Introduction
Background Information
With more than 7.65 followers all over the world, Jehovah’s Witnesses can be considered as one of the minor-stream religions in the world. According to Holden (2002), this religion can be described as a restorationist Christian denomination which is significantly different from mainstream Christianity. Unlike the mainstream Christian denominations, Jehovah Witnesses do not believe in the Holy Trinity. This is the reason why adherents of this faith are sometimes referred to as nontrinitarian Christians (Holden, 2002).
Jehovah Witnesses as a religion traces its roots back to the year 1870. This is the year that the Zion’s Watch Tower Tract Society was formed. The group was an offshoot of the Bible Student Movement and it was formed by Charles Taze Russell, a salesman by profession (Remmers & Speer, 2006). The splinter group was led by Joseph Franklin Rutherford, and it is the group under whose auspices the Jehovah Witnesses exist. The current title of Jehovah Witnesses can be traced back to the year 1931 (Sloan & Ballen, 2008). The name was adopted to differentiate the group from other Bible Student organizations around the world.
This religious group has adopted the door-to-door form of preaching to reach out to more people from around the world. The Witnesses target households and this is perhaps one of the reasons why they prefer moving from one house to the other as opposed to holding outdoor religious crusades and movements. However, the adherents are also known to attend conventions and the annual Memorial which is attended by adherents from all over the world. The conventions have been known to attract more than 12 million adherents while more than 20 million believers attend the Memorial (Holden, 2002).
The life of a Jehovah Witness revolves around the teachings of the Bible. The adherents have been known to prefer their own version of the holy book which they refer to as the New World Translation of the Holy Scriptures (Holden, 2002: p. 56). In fact, the name “Jehovah’s Witnesses” is itself derived from the bible. According to Holden (2002), this is the passage “You are my witnesses, says Jehovah” which is to be found in the book of Isaiah 43: 10 (p. 34).
There are several beliefs that are associated with the adherents of Jehovah’s Witnesses. For example, the adherents conceptualize the bible as an accurate scientific and historical manifestation of Jehovah the God (Sloan & Ballen, 2008). As such, the literature is accurate and reliable. This is the reason why the Witnesses interpret huge chunks of the scriptures literally. This is given the fact that the bible is taken as the “final authority” (Sloan & Ballen, 2008: 45) for the entire belief system.
The adherents of this faith also believe that Jehovah is the correct name of God. This far, Jehovah Witnesses are seen to be reading from the same script with adherents of mainstream Christianity. However, the two belief systems differ when Jehovah Witnesses claim that Jehovah is not part of a Trinity. As such, they do not recognize God the Father, the Son and the Holy Spirit. As opposed to mainstream Christians, Jehovah Witnesses place more emphasis on God the father than on the other two manifestations of God.
Jehovah Witnesses are also firm believers of the Armageddon. To this end, adherents of this faith believe that the world as we know it today will be destroyed. After its destruction, the current world will be replaced with God’s Kingdom which is a perfect manifestation of the world as God desired it to be. Unlike mainstream Christians, Jehovah Witnesses also reject the idea of hell and paradise. On the contrary, they believe that as stated earlier, God will establish His kingdom here on earth. The adherents also fail to observe popular events such as Christmas, Easter, birthdays and such other holidays and practices which are regarded as being contrary to the teachings of the Bible (Holden, 2002).
Jehovah Witnesses take disciplinary measures on members of the congregation who are viewed as having gone against the teachings of the fellowship. According to Holden (2002), the major form of disciplinary action meted out on an unruly member is disfellowship. This is whereby the member is formally expelled from the congregation and shunned by other members. However, there are those adherents who leave the congregation on their own volition. These are regarded as having been disassociated (Holden, 2002). Such members are also shunned by those who remain in the faith.
But perhaps what sets Jehovah Witnesses apart from mainstream Christianity is their steadfast refusal for blood products even in cases of medical emergencies. According to this faith, Jehovah God has prohibited the ingestion of blood. This being the case, adherents of this faith believe that true Christians should object to blood transfusions of any kind. The believer is also prohibited from blood donations or having their own blood stored to be transfused in the future (Holden, 2002).
Refusal of blood transfusion as a policy is contained in the Watch Tower Society writings which are very important to a Jehovah Witness. According to these writings, this stand is non-negotiable. The adherents object not only to transfusions of whole blood but also to its major components (Remmers & Speer, 2006). The four major component referred to here are the red blood cells (herein referred to as RBCs), white cells, blood platelets and blood plasma (Remmers & Speer, 2006). It is noted that a true Christian who regards life as God given gift should never make attempts to sustain it through ingestion of blood or blood components. This is despite the fact that the Witness may be in grave medical danger.
However, the Witnesses are allowed to use some fractions of blood. These are for example albumin, immunoglobulins, haemophiliac preparations among others (Bayam, Tait & McCartney, 2007). However, it is made clear to the Witnesses that the use of these fractions is a matter of personal choice.
The refusal of blood transfusions as a policy and a doctrine in this faith started in the year 1945 (Holden, 2002). Since then, several amendments have been made to this policy. If a member happens to accept a blood transfusion regardless of the situation or circumstances, it is assumed that they have disassociated themselves from the faith. As a result, they are shunned by the others and are prohibited from participating in any activities undertaken by Jehovah Witnesses.
According to Ott, Denton & Cooley (1977), the refusal for blood transfusion on the part of the Jehovah Witnesses poses a professional and ethical challenge to the medical fraternity especially when the adherents of this faith are seeking medical attention. In article titled Cardiovascular Surgery in Jehovah’s Witnesses, Ott et al. (1977) are of the view that the doctor’s desire to safeguard the life of the patient is hampered by the expectations on the part of the patient. The doctor has to respect the wishes of the patient under all circumstances. This is the reason why they should not under any circumstances transfuse the patient with blood if the patient has expressly made it clear that this should not be done. On their part, Jehovah Witnesses are required to sign consent documents before undergoing any surgical procedure. This is to ensure that they cannot blame the doctor for professional negligence should anything go wrong as a result of lack of blood transfusion.
In the past, it is noted that patients who declined blood transfusion on religious grounds were usually denied access to surgical treatment (Ott et al., 1977). However, this trend has changed over time with the development of techniques such as bloodless surgery which have enabled doctors to perform operations on patients without the need for blood transfusion. According to Ott et al. (1977), the first open heart surgery performed on a Jehovah Witness without blood transfusion in Texas Heart Institute was in the year 1964. This is an indication of the fact that medical practitioners have made efforts to accommodate the religious beliefs of Jehovah Witnesses as far as surgery is concerned.
This thesis was written against this backdrop. The researcher is going to analyze the effects of blood transfusions on patient outcomes during cardiopulmonary bypass surgical operations. A comparison will be made between transfused and non-transfused patients as far as their outcomes are concerned. Three articles will be used to carry out this study. The researcher will carry out a metaanalysis of the three articles comparing their methodologies, findings and conclusions. The three articles compare the outcomes of patients who received blood during a cardiopulmonary bypass with those who did not receive blood. In all the three articles, those patients who did not receive blood transfusion were drawn from Jehovah Witnesses denomination. Based on the findings of the metaanalysis, the researcher will draw conclusions as far as the effects of blood transfusion on patient outcomes during cardiopulmonary bypass are concerned.
Problem Statement
As already indicated earlier in this paper, this study will examine the effects of blood transfusions on patient outcomes during cardiopulmonary bypass. A comparison will be made between patients who did not receive blood during the operation with those underwent blood transfusion. The study will be controlled for autologous patients who are transfused with pre-operative self donated blood. This is given the fact that Jehovah Witnesses’ faith prohibits autologous blood transfusions. Jehovah Witness adherents will be taken as the non-transfused group in this study. Their response or reaction to cardiopulmonary bypass will be compared to patients from other faiths and who are transfused.
The researcher will use secondary data as opposed to the use of primary data. Three articles will be accessed from various medical databases. These are the articles that will be meta-analyzed. The findings and conclusions of the three articles will be compared as far as the effects of blood transfusions on patient outcomes are concerned.
Objectives of the Research
This study had one major objective and several specific objectives. These are as listed below:
Major Objective
To compare transfused and non transfused adult cardiac surgery patients and analyze the effects of blood transfusions on patient outcomes during cardiopulmonary bypass
Specific Objectives
- Analyze the effects of blood transfusions on patient outcomes during cardiopulmonary bypass
- Analyze the lowest acceptable hemoglobin and hematocrit level before transfusion is carried out
- Analyze the implications of refusal of blood transfusion on perfusionists during cardiac bypass
- Analyze the link between the perfusionists, professional ethics and refusal for blood transfusion on the part of Jehovah Witnesses
Research Hypothesis
Hypothesis Statement: Adult cardiac surgical patients with no blood transfusion during cardio- pulmonary by- pass surgery have significantly lower morbidity than patients receiving donated blood.
Utility Statement: If indeed non transfused patients have better outcomes, why should perfusionists not employ this procedure on all patients? If the research statement is supported by data from this study, it is noted that little or no donor blood should be used if associated with comorbidities. The debate in perfusionists’ and cardiac surgery’s field in general revolves around the question of the point at which HCT is too low to the extent that it loses its effect. This is especially so given the fact that most patients have diluted HCTs shortly before undergoing cardiopulmonary bypass if their initial HCT is below 30 percent. Patient with more than 40 percent HCT can undergo bypass without the diluted HCT.
Explanation of the Utility Statement
It is noted that it is the role of perfusionists to administer blood transfusion during cardiac bypass. The perfusionist starts by washing the blood units into a cell saver and putting the same in a pump to improve HCT. This is especially so if the HCT level falls to an acceptable level which is below 30 percent in most literatures. The level of HCT may decline due to hemodilution with crystalloid.
It is noted that perfusionists have a direct impact on the moral beliefs the patients under their care. This being the case, it is important for the perfusionist to be well versed on how to deal with a patient who refuses to have blood transfusion on religious or other grounds. To this end, effective communication with other professionals involved in the cardiac bypass such as anesthesiologists and the surgeons is paramount. This is given the fact that the surgeon will base their decision on whether to perform the surgery or not based on the anticipated blood loss.
Incompetent perfusionists can warrant unnecessary blood transfusions due to loss of blood from the pump as a result of accidents. Unwarranted use of crystalloid as a result of poor volume control can also lead to unnecessary blood transfusions. This is in addition to other shortcomings on the part of the perfusionist such as carrying out a distal anastomosis while the heart is torqued over during a CABG (Ranucci et al., 2006).
Patients such as Jehovah Witnesses and other non transfused patients make it clear that no blood should be added into their system in cardiac bypass. This being the case, the perfusionists should be diligent enough to ensure that conditions calling for blood transfusion during the procedure are averted. This is for example avoiding low HCT and over hemodilution (Ranucci et al., 2006).
If, according to the hypothesis of this research, patients who do not receive a blood transfusion have better post cardiac bypass surgical outcomes than those who receive blood transfusion, then efforts should be made by the perfusionist not to administer blood transfusion on any patient undergoing bypass regardless of their religious beliefs. It is a fact beyond doubt that Jehovah Witnesses and other patients who refuse blood transfusion pose a challenge to the perfusionist, the surgeon and other practitioners carrying out a bypass. This is given the fact that mistakes or accidents that may lead to surgical bleeding and consequently blood transfusion have to be avoided. However, the same treatment should be extended to other patients even those who have not out rightly objected to blood transfusion. Perfusionists have the ability to prevent unnecessary blood transfusion by being diligent and acting professionally. This research thesis will try to address this issue.
Significance of the Study
The importance of the findings of this study to the field of blood transfusion and the perfusionist’s profession in general cannot be downplayed. The following are some of the uses of the findings of this study in this field:
- The findings of the study will help perfusionists understand better the effects of blood transfusions on outcomes of patients undergoing cardiac bypass
- The findings will help the perfusionists compare the impacts of blood transfusion and non transfusion during cardiac bypass
- The findings will help perfusionists improve their performance during cardiac bypass by highlighting the importance or lack of it thereof as far as blood transfusion is concerned
Scope and Limitations of the Study
It is noted that it is not possible to address each and every dimension of a research topic in a single study. This is the reason why the researcher has to demarcate boundaries within the larger field, boundaries within which the current study will be conducted. Perfusionist and cardiopulmonary bypass are such fields which are diverse and multifaceted. This being the case, the current study cannot confidently address each and every dimension in this field. The scope and limitations of this study will help the researcher focus and address effectively and exhaustively a given dimension of the field. The following are the limitations and scope of this study:
- Jehovah Witnesses will form the non-transfusion patients’ category. The researcher will focus on Jehovah Witnesses despite the fact that there are other patients who undergo cardiac bypass without receiving blood transfusion on various grounds
- The study will be limited to transfusion vs. non- transfusion surgical procedures during cardiac bypass. This is despite the fact that the issue of blood transfusions and non- transfusion surgery is to be found in other medical fields such as oncology, neurology and such others
- The study will focus on adult cardiac patients. Pediatric patients and those below 21 years of age were not included in this study. This is despite the fact that there are pediatric patients who undergo bloodless bypass surgery
- The researcher will make use of secondary data. It is three articles from this field which will be meta-analyzed. This means that primary data will not be part of this study
Literature Review
Overview
In this section, the researcher will critically analyze literature that is to be found in this field. The major aim of literature review is to identify agreements and disagreements between different schools of thought in the field. The literature review will also be aimed at identifying knowledge gaps that exists in the field and which can be addressed effectively by the current or future studies in the field. Critical literature review will also help in locating the current study within the larger field of perfusion and cardiac bypass procedure. This is by helping the researcher to compare the current study with what has been already done in the field and how the current study fits into the whole picture. Critical literature review will also help the researcher in avoiding duplication of studies that have already been carried out in the study. This is by familiarizing themselves with findings of studies that have been carried out in the field in the past.
Bloodless Surgery and Jehovah’s Witnesses
Overview
According to Ott et al. (1977), several bloodless surgeries have been carried out over the years to cater for Jehovah Witnesses and other patients who object to blood transfusions. There are other reasons why patients decline blood transfusions during surgical procedures. These range from concerns revolving around infections such as AIDS, hepatitis and such others (Ranucci et al., 2010).
To this end, more than 200 hospitals around the world offer bloodless surgery for those patients who object to blood transfusions (Ranucci et al., 2010). Bloodless surgery has been carried out successfully in invasive surgical procedures such as open heart surgery.
Bloodless surgical procedures pose a challenge to both the patient and the practitioner carrying out the procedure. This is given the fact that there are certain procedures which cannot be carried out effectively without blood transfusions. This is the reason why some practitioners advocate for allogeneic blood products and pre-operative autologous blood transfusion to cater for such patients (Thompsons, Edwards & Stout, 2008).
A Critique of Bloodless Surgery within the Context of Jehovah’s Witnesses
Apart from it being viewed as a challenge to medical practitioners as far as saving lives is concerned, bloodless surgery within the context of Jehovah Witnesses has received criticism from various quarters. There are those who view the permission by the Watchtower Society for tiny fractions of blood during medical procedures with disdain (Holden, 2002). For example, albumin and other blood fractions admissible in bloodless surgery make up a larger percentage of blood components than some derivatives of blood that are prohibited. Albumin makes up about 2.2 percent of blood volume while other components such as white blood cells and platelets which are prohibited account for 1 percent and 0.17 percent respectively (Ho & Leonard, 2011). Hemophiliac treatments which call for collection and storage of large volumes of blood are permitted by Jehovah Witnesses. According to Ranucci et al. (2010), a single haemophiliac treatment can require more than 2000 blood donors. While this massive collection and storage of blood is acceptable to the Watchtower, preoperative autologous blood transfusion which involves the blood of the patient only is prohibited.
Critics have argued that the interpretation of the Bible by Jehovah Witnesses as far blood transfusion is concerned is fallacious and erroneous to say the least. A verse that is usually regarded as the origin of this refusal for blood transfusion is Leviticus 17: 14. This verse states that “for it is the life of all flesh; the blood of it for the life thereof; therefore I said unto the children of Israel, Ye shall eat the blood of no manner of flesh; for the life of all flesh is the blood thereof; whosoever eateth it shall be cut off” (Holden, 2002: p. 56). A critical interpretation of this verse reveals that eating blood is what is prohibited in the scriptures. But blood transfusion is not feeding on blood (Ho & Leonard, 2011). This is given the fact that the recipient accrues no nutritional benefit from the procedure. The blood is not digested; rather, it is retained in the recipient’s system more or less like a donated organ (Ranucci et al., 2010).
Opinion of Practitioners Regarding Bloodless Surgery within the Context of Jehovah Witnesses
Practitioners acknowledge the fact that the refusal for blood transfusions on the part of Jehovah Witnesses is a major challenge to their practice. However, according to Ott et al. (1977), studies have shown that the patients are cooperative if they are assured that their religious beliefs will be catered for during the procedure. At the time Ott et al. (1977) were conducting their study, there was no single claim against the hospital that had been lodged by a Jehovah Witness who has undergone surgical procedures. As a result of this, it is obvious that the patient has a right to make their own decisions regarding the form of medical procedure that they desire. Perfusionists and other practitioners have the moral duty to respect such desires and wishes.
However, Ott et al. (1977) caution that special considerations should be given to pediatric patients undergoing medical procedures. If the practitioner is of the opinion that extensive blood loss is inevitable, then surgery should not be recommended (Ott et al., 1977). Simple medical procedures such as correcting a patent ductus arteriosus or a ventricular septal defect can however be performed through bloodless surgery in pediatric patients. However, things are a bit complicated when it comes to major medical procedures such correcting anomalies such as tetralogy of Fallot (Bayam et al., 2007).
Lowest Hematocrit and Impacts during Coronary Surgery
Ranucci et al. (2006) are of the view that morbidity and mortality rates in patients who have undergone coronary surgical procedures can be increased by elevated by hemodilutional anemia. In a retrospective study of 1766 adult patients who have undergone cardiopulmonary bypass, Ranucci et al. (2006) analyzed lowest hematocrit values during extracorporeal circulation as a risk factor. This was together with allogenic blood transfusions during the same procedure.
Laurent et al. (2011) are of the view that hemodilution is an important aspect of cardiopulmonary bypass. It is noted that hemodilution enhances “peripheral perfusion and blood flow to tissues and (enhances) venous return” (Ranucci et al., 2006: p. 301). Hemodilution is also important during hypothermic surgical procedures. In both instances, hemodilution is shown to reduce viscosity thus improving perfusion (Churchhouse et al., 2011). It is noted that allowing for anemia through hemodilution on the part of the perfusionist is likely to reduce unnecessary blood transfusions.
However, critical limits of hemodilutional anemia during cardiac bypass have not yet been established. On the contrary, many studies have indicated that low hematocrit values brought about by hemodilution poses various challenges to medical practitioners during a cardiac bypass procedure (Ranucci et al., 2006).
Ranucci et al. (2006) found that lowest hematocrit values were significantly linked to morbidity characterized by LOS, lung and renal dysfunction among others after cardiac bypass. Cases of mortality were also reported as a result of low hematocrit values. Nadir hematocrit values were as such identified as risk factors during cardiac bypass procedures and in extension, other surgical procedures that may call for the skills of a perfusionist.
There are various causes of hemodilutional anemia during cardiac bypass and other medical procedures. A case in point is a prolonged cardiac bypass procedure (Churchhouse et al., 2011). When this happens, perfusionists have no option by to administer more cardioplegic solutions accompanied by increased fluid volumes which lead to elevated hemodilution. As a result of this, prolonged cardiac bypass procedure can be regarded as a morbidity and mortality risk factor in itself.
The relationship between nadir hematocrit values and myocardial dysfunctions is another grey area in perfusion and medical surgery field. From a study cited in Ranucci et al. (2006), Spiess and his colleagues found that post-cardiac bypass hematocrit levels exceeding 34 percent are positively related to myocardial infarction. Hemodynamic instability has also been shown to cause post- surgery anemia (Cacciarelli et al., 1999).
Intraoperative Blood Transfusion, Mortality and Morbidity in Non- Cardiac Surgery
It has already been pointed out that blood transfusion and lack of it thereof is not limited to cardiac surgical procedures. There are other surgical procedures that are significantly affected by the dynamics of blood transfusion.
Laurent et al. (2011) are of the view that the effects of Intraoperative erythrocyte transfusion on the outcomes of anemic patients who have undergone a non- cardiac surgical procedure are little understood. In a 2011 study published in Anesthesiology journal, the researchers sought to find out the link between blood transfusion and mortality and morbidity rates. Severe anemia is defined by these scholars as that which is characterized by hematocrit values which are less than 30 percent. This definition is consistent with that given by other scholars such as Ranucci et al. (2006). However, Laurent et al. (2011) controlled their study for those patients who were exposed to 1 or 2 units of erythrocytes intraoperatively.
A multivariate logistic regression model controlled for 30- day mortality and 30 –day complications was adopted.
In conducting this study, Laurent et al. (2011) acknowledged the fact that Intraoperative blood transfusion on patients undergoing major surgical procedures was seen to increase morbidity and mortality rates. This was especially so in patients with acute anemia during the operation. This assumption is in line with what is already known in this field. Many researchers in the past have come to associate Intraoperative blood transfusions with negative effects on the outcomes of patients who have undergone surgery. In this study, Laurent et al. (2011) wanted to find out whether these negative impacts on patient outcomes could be directly linked to blood transfusion during the operation. This is given the fact that the scholars were also aware of the fact that the negative effects on outcomes could be associated with critical blood loss during the operation.
In order to increase the accuracy of this study, Laurent et al. (2011) used patients who showed severe anemia preoperatively as the subjects for the study. These preoperative anemic patients were transfused during the surgical procedure. Their outcomes were compared with those of patients who did not receive transfusion. The aim of using these patients (preoperative anemic patients) was to reduce the effects of Intraoperative blood loss on the outcomes of the patients. As such, the researchers could thus control the study for severe baseline anemia (Ranucci et al., 2006).
34 percent of those patients who recorded preoperative hematocrit levels ranging from 15 percent to 23.9 percent received erythrocyte transfusion intraoperatively (Laurent et al., 2011). On the other hand, 18 percent of those patients who recorded preoperative levels ranging from 27 percent to 30 percent were transfused.
It was found that 30 day mortality rate for those subjects who were exposed to erythrocyte intraoperatively was 6.44 percent. This is as compared to 4.26 percent of those patients who were not exposed to red blood cells. The researchers found that blood transfusion was linked to increased mortality rates. It was also found that those subjects who received transfusion were more likely to have post- operative complications. This is as compared to those patients who did not receive blood transfusions.
The findings and conclusions of this study are similar to those of studies conducted in the past in the same field. For example, in a study conducted by Koch and his colleagues and cited in Churchhouse et al. (2011), it was found that erythrocyte transfusion did increase the mortality and morbidity risks of those patients undergoing coronary bypass grafting procedures. In another study conducted by Murphy and his colleagues using subjects from the United Kingdom, it was also found that erythrocyte increased the risk for ischemic complications in cardiopulmonary surgical patients (as cited in Ho & Leonard, 2011).
However, there are few studies in this field which have come up with slightly different findings. As reported earlier in this paper, a retrospective analysis of more than 8000 patients carried out by Carson et al. (as cited in Ranucci et al., 2010) is such one study. According to these scholars, pre- operative or post- operative blood transfusion was not linked to changes in mortality and morbidity rates after the operation. This is after nadir hematocrit was adjusted for the patients taking part in the study. However, it is important to note that Carson’s study was conducted on subjects undergoing surgical repair or hip fractures and not cardiopulmonary surgical procedures (Ranucci et al., 2010). However, regardless of the difference in the background of the patients used, the subtle variation of these findings cannot be downplayed.
Laurent et al. (2011) conclude that Intraoperative blood transfusion is in fact linked to increased post- operative morbidity and mortality rates on the patients. In other words, blood transfusion has negative effects on the outcomes of patients undergoing surgical procedures. However, most studies have failed to establish the exact association between blood transfusion and negative outcomes on the patients. As Laurent et al. (2011) candidly state in their conclusion, the link between blood transfusion and negative effects on the outcomes of the patients was not known whether it was emanating from the negative effects of the blood transfusion or from elevated loss of blood by those patients undergoing operation. It is a fact beyond doubt that perfusionists will find it necessary to transfuse those patients who are likely to or have already lost a lot of blood during the operation. This being the case, it is possible that the reported negative outcomes after the operation could indeed be associated with this blood loss and not from the transfused blood per se (Cacciarelli et al., 1999).
However, it is important to note that despite the arguments given above regarding the ambiguous relationship between blood transfusion and negative outcomes on the part of the patients, studies have increasingly shown that blood transfusion does not improve the outcomes of the patients (Thompson, Edwards & Stout, 2008). It is a fact beyond doubt that anemia (either pre-operative, intra- operative or post- operative anemia) does increase morbidity and mortality as far as the patient is concerned. And this is one of the reasons why perfusionists find it important to transfuse the patients. However, this does not rule out the fact that blood transfusion does not in any way improve the outcomes of the patients undergoing surgical procedures.
Guidelines on Blood Transfusion
For the longest time, professionals in this field have been aware of the fact that blood transfusion is associated with negative outcomes on the part of the patients. Despite the fact that there is lack of sufficient scientific evidence to tie negative outcomes exclusively to blood transfusion, the professionals have realized that it is important to regulate the practice of blood transfusion during and after operations. To this end, the professionals have come up with policies and guidelines addressing blood transfusion on patients undergoing surgery.
The Transfusion Requirement in Critical Care is one of the professional organizations that provide perfusionists with guidelines on how and when to administer blood transfusion (Ranucci et al., 2006). This organization recommends a restrictive transfusion strategy for critical patients admitted in the Intensive Care Unit (Ranucci et al., 2010). To this end, the organization is of the view that blood transfusion should be controlled depending on the condition of the patient. FOCUS is another organization that provides perfusionists with policies and guidelines addressing blood transfusion on patients undergoing medical procedures. FOCUS limits itself to post- operative surgical patients regardless of whether they are admitted in the intensive care unit or not. However, just The Transfusion Requirement in Critical Care entity, FOCUS is of the view that blood transfusion should be controlled and should be informed on the condition of the patient among other factors.
Currently, guidelines addressing blood transfusion use the patient’s hemoglobin concentration as a major factor in making decisions regarding blood transfusion (Ranucci et al., 2006). Most professional organizations and most studies advise the perfusionist to administer blood transfusion if the patient’s hemoglobin concentration falls below 6 g/dl (Thompson et al., 2008). This is the nadir hemoglobin concentration that calls for blood transfusion. This recommendation is very significant to those perfusionists and surgeons who are dealing with patients who object blood transfusion. These are patients such as the Jehovah’s Witnesses who are the subject of this study. If the practitioner strongly feels that hemoglobin levels of the patient may fall below 6 g/dl during operation, they should avoid carrying out the surgical procedure. This is given the fact that the procedure will put the life of the patient at risk.
On the other hand, the professionals and studies conducted in this field advise that perfusionists should avoid administering blood if the patient’s hemoglobin concentration is above 10 g/dl (Ranucci et al., 2010). Blood transfusion carried out when hemoglobin levels are above this level is, according to this recommendation, unnecessary.
However, it is important to note that there are some areas of surgical operation which are not covered by the recommendations given above. For example, Laurent et al. (2011) are of the view that the recommendations leaves out Intraoperative blood transfusion on patients whose hemoglobin concentrations lie between the two extremes. It is noted that it is up to the perfusionist to determine whether blood transfusion will be necessary when the patient’s hemoglobin concentrations lie between 6 and 10 g/dl.
Blood Transfusion and Impacts on Patients’ Outcomes
Preamble
So far, this paper has consistently portrayed that blood transfusion has a negative impact on the outcomes of patients undergoing surgical procedures. The paper has focused on those patients who are undergoing cardiopulmonary surgical procedures. However, it is noted that the negative impacts of blood transfusion is not limited to the cardiopulmonary field. Other surgical procedures such as hip replacements, neurology among others also have to put into consideration blood transfusion and the impact it has on the outcomes of the patients.
It is important to try and address the question of exactly why blood transfusion is associated with negative outcomes. As it has already been noted, the exact connection between blood transfusion and the negative outcomes is not well known. However, this paper will try to address the adverse effects of blood transfusion from a general perspective. This will shed some light on why the procedure is associated with increased morbidity and mortality rates on the part of the patients.
Negative Effects of Blood Transfusion
According to Bayam et al. (2007), the complications associated with blood transfusion can be grouped into two broad categories. These are immunological and infectious effects (Bayam et al., 2007). Apart from the negative impacts arising from blood transfusion per se, there are those in the field of perfusion who argue that complications arising from blood transfusion may be directly or indirectly related to quality degradation of the blood components during transportation and storage (Churchhouse et al., 2011). This is whereby the blood or blood components are stored under poor conditions leading to the death of the blood cells. It has also been noted that chemical compounds used to line the plastic bag used to transport and store blood and blood components may leach into the components stored within it. The chemical reaction between the blood components and the chemical compounds may affect its quality in the long run (Laurent et al., 2006). The blood will in extension react with the immune system of the recipient and this reaction may lead to post- operative and other complications.
Analysts have noted that the negative effects of blood transfusion in the United States of America accounts for about seventeen billion dollars (Cacciarelli et al., 1999). These are the costs incurred in treating the conditions arising from the blood transfusion among others. This being the case, it is noted that the cost of a single blood transfusion is more than that of acquisition of the blood or blood components and the transfusion procedure all combined (Ranucci et al., 2010).
It is noted that morbidity and mortality arising from blood transfusions may be related in part to the status of the patient. This is the reason why most studies addressing blood transfusion controls for variables such as age, sex and the medical history of the patient. Other risks as far as blood transfusion is concerned are related to the quantity of blood transfused and the blood components that are transfused. Again, this is the reason why most studies control for the two variables. For example, in Laurent et al. (2011)’s study cited earlier in this paper, the researchers addressed erythrocyte transfusion. This was limited to one or two units but not more than that.
Many studies have found that complications arising from blood transfusion increases with a rise in frequency and volume of transfusion (Churchhouse et al., 2011). What this means is that frequent blood transfusion is not recommended since it increases the likelihood of the patient developing complications. Similarly, the transfusion should be regulated as far as volume is concerned. This is given that increased volumes increase the likelihood of the patient developing complications.
So, what exactly are some of the adverse effects of blood transfusion? The paper will address the two broad categorizations given above in this section. These are immunologic and infectious complications.
Immunologic Complications
There are several complications under this broad category:
Acute Hemolytic Reactions
According to Ho & Leonard (2011), this complication is associated with transfusion of erythrocytes. It is noted that approximately 0.016 percent of blood transfusions lead to this form of complication. Approximately 0.003 percent of these complications are fatal, meaning that they can lead to mortality (Ho & Leonard, 2011).
Acute hemolytic reactions are attributed to the destruction of donor red blood cells by the patient’s preformed antibodies (Churchhouse et al., 2011). Most scholars attribute this to clerical errors or erroneous typing and cross matching during the transfusion process. If the perfusionist suspects acute hemolytic reactions, the process should be stopped and the donor blood evaluated for hemolysis. If this complication is unchecked, it might lead to pigment nephropathy which affects the kidneys of the patient (Churchhouse et al., 2011).
Febrile Non- Hemolytic Reactions
This is reported in approximately 7 percent of blood transfusions. It is attributed to the reaction of the patient’s antibodies to the white blood cells in the donor’s blood. According to Ho & Leonard (2011), this reaction is heightened in those patients who have already been exposed to previous transfusions. Antipyretics are generally used to combat the fever arising from the reaction.
Febrile non- hemolytic reactions is one of the reasons why perfusionists have adopted leukoreduction before transfusions. This is whereby white blood cells are eliminated from the blood components to reduce the reaction of patient to them.
Post- Transfusion Purpura
This complication is very rare in the field of perfusion (Churchhouse et al., 2011). It is reported when the transfused components contain platelets with HPA- 1a surface protein (Churchhouse et al., 2011). The complication is reported in those patients who lack HPA- 1a. They are sensitized to HPA- 1a from previous transfusions. Thrombocytopenia is reported to occur in these patients approximately 7 to 10 days following subsequent blood transfusions (Ranucci et al., 2010). The perfusionists can treat this complication using intravenous immunoglobulin. To avoid complications in the future, the perfusionists should make sure that the patient receives blood components with washed or HPA- 1a negative cells (Ranucci et al., 2010).
Transfusion Associated Acute Lung Injury
Transfusion Associated Acute Lung Injury (herein referred to as TRALI) is another immunological complication that is associated with blood transfusion (Laurent et al., 2011). This complication is associated with acute respiratory distress. It is reported in about 0.05 percent transfusion cases. Symptoms of this complication include non- cardiogenic pulmonary edema and hypotension (Laurent et al., 2011).
Patients reporting this complication recover fully within 4 days. Mortality rate for this complication has been recorded at less than 1 in every 10 patients. The cause of this condition remains unclear to professionals in this field. However, studies have continually linked it to anti- HLA antibodies (Laurent et al., 2011). It is noted that the aforementioned antibodies are usually formed during pregnancy. As a result of this, most perfusionists have opted to plasma from male donors to avoid this complication.
Allergic Reactions
This is another immunologic complication associated with blood transfusion. According to Ho & Leonard (2011), this complication is usually recorded in those patients who have preformed antibodies to specific chemical components in the transfused blood. Prior exposure to transfusion is not a prerequisite for this complication.
The major symptoms for this condition are urticaria and pruritus (Cacciarelli et al., 1999). This may to anaphylactic shock if it remains unchecked. According to Cacciarelli et al. (1999), this condition is especially common in those patients who lack immunoglobin lgA. These makes up about 0.13 percent of the whole population. When such patients are exposed to donor blood with the immunoglobin lgA, they may develop an anaphylactic reaction (Cacciarelli et al., 1999).
Infectious Complications
Just like in the case of immunologic complications, there are many conditions under this category:
Transfusion Transmitted Bacterial Infection
This is a rare infectious condition where donor blood has been contaminated with bacteria (Cacciarelli et al., 1999). In the year 2002, it was estimated that approximately 0.002 percent of platelet transfusions and approximately 0.0002 percent of erythrocyte transfusions had severe bacterial infection (Ho & Leonard, 2011).
Bacterial contamination of donor blood has been shown to increase with the duration of time the blood is stored. It is especially common in blood components that have been stored for a period longer than 5 days (Cacciarelli et al., 1999). It is also noted that the contamination is most common in blood platelets as opposed to other blood components. Apart from the duration of storage, there are other factors which can lead to contamination of the blood on the part of the donor. Such other sources of blood contamination may include donor’s skin when the blood comes into contact with the skin during donation, phlebotomist’s skin among others. As it has already been alluded to earlier in this paper, the contamination may also arise from chemicals and compounds leaching from the blood container (Churchhouse et al., 2011).
Transmission of Infections such as HIV and Hepatitis
It is noted that there are other forms of infections that can transmitted via blood transfusion. A case in point is HIV seropositive blood being transfused to a patient undergoing operation. However, this form of infection has been greatly reduced since the early 1980s when equipments to test donor’s blood for HIV were innovated.
Other infections that can be transmitted through blood transfusion include hepatitis C (Churchhouse et al., 2011). This is a low rate by any standards. The low rates have been associated with the enhanced ability to screen for antibodies and nucleic acid for the viral RNA before the blood is transfused into the patient.
There are other rare infections that are transmitted through blood transfusion. This is for example hepatitis B and syphilis (Ranucci et al., 2010). Others are Chagas disease, cytomegalovirus, HTLV among others (Ranucci et al., 2010).
Other Adverse Effects of Blood Transfusion
Transfusion Inefficacy
According to Ho & Leonard (2011), the inefficacy is not a complication per se. However, it is noted that the condition can lead to a multitude of other complications given that it creates the need for subsequent transfusions. It has been noted that this inefficacy is significant for critical care patients who need frequent blood transfusions for various reasons. This is for example to restore oxygen delivery in the critical patients.
There are several factors that can lead to transfusion inefficiency. For example, the blood components might have been damaged by storage lesion which may lead to decreased viability of erythrocytes. Storage lesion can also lead to reduced ability of tissue oxygenation (Ranucci et al., 2010).
Transfusion Associated Volume Overload
This complication is brought about by the simple fact that blood components have a given volume (Ranucci et al., 2010). This complication is especially common in patients who have underlying cardiac or kidney conditions. Volume overload can also be linked to insufficient efficacy. This is given the fact that insufficient efficacy creates the need for repeated transfusions (Ranucci et al., 2010). Some blood components are more hypertonic than others and as such, they tend to increase the risk for transfusion associated volume overload. This is for example components such as plasma which have higher volume than others such as red blood cells.
Hypothermia
This is also associated with large volumes of transfusion (Cacciarelli et al., 1999). This is especially so considering the fact that most blood components are stored under low temperatures. It is noted that the patient’s body temperature can plummet to low levels such as 32 degrees Celsius (Cacciarelli et al., 1999). Hypothermia can lead to physiologic disturbances. Perfusionists can avoid this by warming the blood before transfusion.
Inclination for Bleeding
This is also brought about by transfusions with large volumes of blood components. The increased volume can be necessitated by hemorrhaging or transfusion inefficacy. When this happens, it is believed that intravascular coagulation. The perfusionist should monitor the condition of the patient closely and transfuse with platelets (Ranucci et al., 2006).
There are other conditions which are associated with massive blood transfusions. This is for example metabolic alkalosis. This condition is brought about by the breakdown of citrate found into blood into bicarbonate (Ranucci et al., 2006). Others are hypocalcaemia which is brought about by the combination of citrate and serum calcium in the blood (Ranucci et al., 2006).
Summary of the Articles Used in the Study
As already indicated in this paper, the researcher made use of three articles in this study. The study was a metaanalysis of these three articles. The three were compared with regard to the methodologies used, the findings made and the conclusions drawn. The findings of the articles were also located within the larger blood transfusion and cardiopulmonary field.
It is then important to look at a summary of the three articles at this juncture. This is to introduce the reader to the articles and to give them an idea of what the articles are all about. The researcher will provide the reader with only a brief summary of these articles. This is given the fact that the articles will be analyzed in detail later on in the paper.
Thesis Article 1: How Good Patient Blood Management Leads to Excellent Outcomes in Jehovah’s Witness Patients Undergoing Cardiac Surgery by Emmert et al.
This article was published in the Interactive CardioVascular and Thoracic Surgery journal in 2011. It is a fairly recent article where the researchers try to analyze the effects of good patient blood management on Jehovah Witness patients. In the article, the scholars admit that the refusal of blood products by these patients during surgical procedures leads to an ethical challenge on the part of the care provider.
The study involved a total of 16 Jehovah Witness patients. All of them underwent cardiac surgical procedure at the Clinic for Cardiovascular Surgery, University Hospital Zürich (Emmert et al., 2011). This was in a span of 6 years (between 2003 and 2008). All the 16 patients survived the operation with no major complications.
The scholars arrived at the conclusion that improved patient blood management practices results into improved short term and long term patient outcomes. This is especially so if the practice is accompanied by “meticulous surgical techniques” (Emmert et al., 2011: p. 183).
Thesis Article 2: Comparison of Cardiac Surgery Outcomes in Jehovah’s Versus Non- Jehovah’s Witnesses by Stamou et al.
This study was comparative in nature. The scholars compared the outcomes of Jehovah Witness patients who underwent surgery without blood transfusion with the outcomes of those patients who underwent surgery with blood transfusion. The findings of the study were published in the American Journal of Cardiology in the year 2006.
The scholars compared the “operative mortality and early clinical outcomes after open cardiac surgery” (Stamou et al., 2006: p. 1223) between Jehovah Witness patients who underwent bloodless surgery and non- Jehovah Witness patients who received blood products when undergoing surgery.
A total of 245 open heart surgery patients were used in this study. These included 49 Jehovah Witnesses and 196 non- Jehovah Witnesses (Stamou et al., 2006). The data used for the study was collected between January 1990 and July 2004 (Stamou et al., 2006).
The scholars found no significant differences between the two groups of patients in most of the outcomes analyzed. The outcomes included acute myocardial infarction, new- onset atrial fibrillation, unadjusted stroke, acute renal failure and hemorrhage- related re- exploration (Stamou et al., 2006).
This article came to the conclusion that cardiac surgical procedures among the two groups of patients are associated with comparable clinical outcomes (Stamou et al., 2006). This is so if the perfusionist and other medical practitioners involved in the surgical procedure adhere to blood conservation protocols.
Thesis Article 3: Bloodless Cardiac Surgery in Jehovah’s Witnesses: Outcomes Compared with a Control Group by Reyes et al.
The findings of this study were published in the Rev Esp Cardiol journal in the year 2007. The scholars start by acknowledging the fact that the refusal of blood products by some patients is a problematic issue on practitioners in this field. In this study, the scholars sought to find out whether the “clinical characteristics and surgical outcomes in Jehovah’s Witnesses undergoing cardiac surgery are similar to those in other patients” (Reyes et al., 2007: p. 727).
The scholars used 59 Jehovah Witnesses and a similar number of non- Jehovah Witnesses for the study. The study used data for the period between January 1998 and September 2006 (Reyes et al., 2007). The researchers compared pre- operative, intra- operative and post- operative data in this study.
The study found that clinical traits among the 2 groups of patients were similar. However, Jehovah Witnesses’ patients reported reduced levels of bleedings as compared to non- Jehovah Witnesses. However, post- operative complications and mortality was comparable between the two groups (Reyes et al., 2007).
The scholars concluded that patients demanding for bloodless cardiac procedures can record comparable outcomes with those who were transfused. This is when the two groups are matched for pre- operative clinical characteristics such as age, gender and such others
Chapter Transition
In this chapter, the researcher introduced the reader to the study by highlighting some of the areas that will be addressed in the study. The reader was provided with a detailed analysis of the significance of this study, statement of the problem and review of literature. The literature reviewed was that to be found in the field of perfusion especially that touching on transfused and non- transfused cardiac surgical procedures. A highlight of Jehovah’s Witnesses and their belief in bloodless surgery as well as the effects of transfusion were analyzed. The researcher also provided the reader with the hypothesis of the study as well as the goals and objectives.
In chapter two, the researcher is going to look at materials and methods utilized in this study. The investigative procedure that was adopted for this study will be analyzed as well as a detailed description of the research methodology.
Materials and Methods
Introduction
In this section, the researcher is going to look at the materials and methods that were adopted for this study. This will begin with a brief overview of the investigative approach to be adopted. This will then be followed by a detailed description of the research methodology. The aim of this section is to provide the reader with an idea of the steps that were followed in carrying out the study.
Meta- Analysis: A Brief Overview of the Investigative Approach
As already indicated earlier in this paper, the researcher is going to adopt meta- analysis as the preferred investigative approach. The three articles that were identified above are going to be meta- analyzed for this study. This being the case, it is important then to look at meta- analysis as an investigative procedure and address some of its major highlights.
Glass, 1976 (as cited in DeCoster, 2004) defines meta- analysis as a “detailed analysis of a large collection of analysis results for the purpose of integrating the findings” (DeCoster, 2004: p. 2). To this end, a researcher applies statistical techniques in analyzing the findings of other studies that have been conducted in the field of their interest.
According to DeCoster (2004), the major aim of this investigative technique is to “…….provide the same methodological rigor to a literature review that (is) required from experimental research” (p. 2). In other words, this author is trying to say that meta- analysis is different from conventional literature review. Whereas literature review as we know it merely provides a narrative of the findings of studies conducted in a given field and the agreements and disagreements of scholars in that field, meta- analysis goes a step further. Meta- analysis involves the methodical and statistical analysis of the findings of other studies in the field.
There are several forms of meta- analysis that can be conducted by the researcher in any given field. The selection of a preferred form of meta- analysis depends on various factors. One such factor is the aims and objectives of the meta- analysis. A meta- analysis that requires statistical analysis of large volumes of studies or data requires a different approach from that adopted when dealing with a small volume of data. What this also means that the availability of data will determine the form of meta- analysis to be adopted (DeCoster, 2004).
According to DeCoster (2004), meta- analytic summaries is one such form of meta- analysis adopted by researchers in a given field. Unlike the conventional meta- analysis which is usually used in reviewing primary research articles and papers, this form of meta- analysis is mainly used within primary research articles (DeCoster, 2004). To this end, the researcher makes use of meta- analysis to provide more information aimed at addressing the primary study’s theoretical framework. The aim here is to provide the researcher with an idea regarding the general “strength or consistency of a given relationship within the studies being conducted” (DeCoster, 2004: p. 3).
The other form of meta- analysis as identified by DeCoster (2004) is ‘quantitative literature reviews’. This is the most common form of meta- analysis and it is also the one which is going to be adopted for the current study. It mainly involves the review of articles reporting findings of primary studies. In the article reviews, the researcher “……selects a research finding or ‘effect’ that has been investigated in primary research under a large number of different circumstances” (DeCoster, 2004: p. 3). To this end, meta- analysis is used to describe the overall strength of the identified effect. The researcher also tries to analyze the circumstances under which the particular effect is weak or strong (DeCoster, 2004).
In the context of the current study, the researcher is going to carry out a quantitative literature review of the three articles that were selected. The researcher will investigate the effects of transfused versus non- transfused outcomes on patients who have undergone cardiopulmonary bypass surgery. The articles that will be analyzed compare the clinical outcomes and other characteristics between those patients that received blood products and those who did not. Jehovah Witnesses will be used as representatives of the non- transfused group. By carrying out the meta- analysis, the researcher will be trying to describe the overall “………strength of (blood transfusion) and under which circumstances the ‘effect’ is stronger and weaker” (DeCoster, 2004: p. 3).
Methodology Adopted for this Study
In this section, the researcher is going to provide the reader with a detailed description of the research methodology that was adopted for this study. To this end, the researcher will provide information on the steps that were followed from formulation of the research problem to the selection of articles that will be used in the study.
The following were the steps that were followed for this meta- analysis:
Formulation of the Research Problem
The researcher started this study by defining the research problem to be addressed. This began with a literature review that was carried out to determine what already exists in the field. This was to help the researcher come up with a hypothesis and corresponding research questions.
The researcher was interested in finding out the effects of blood transfusion on patient outcomes during cardio- pulmonary bypass. From the literature review, it was evident that most studies in the field compared the outcomes of patients who received blood products with those who did not receive them. Further analysis of literature in this direction revealed that Jehovah Witnesses insisted on bloodless surgery. It is at this stage that the researcher decided to analyze the effects of blood transfusions by comparing outcomes of Jehovah Witnesses who did not receive blood products with the outcomes of patients who received the products.
At the end of the literature review, the researcher had formulated the research problem and the hypothesis to be tested. The hypothesis statement that the researcher settled for read:
Adult cardiac surgical patients with no blood transfusion during cardio- pulmonary by- pass surgery have significantly lower morbidity than patients receiving donated blood.
This thesis statement or hypothesis appears on chapter one of this paper. The researcher settled for the statement given the fact that it was felt it is a precise and intellectually stimulating hypothesis. The hypothesis was informed by a theoretical framework. This was the theory that blood transfusion affects the outcomes of patients during cardio- pulmonary by- pass.
The next step after formulating the research question was to “limit the phenomenon of interest” (DeCoster, 2004: p. 5). To this end, the researcher set out to identify the population with which the study will be conducted. This was performed by coming up with definite inclusion and exclusion criteria for the study (this will be analyzed in detail later on in the paper). The aim here was to limit the scope of the articles that will be analyzed so that all of those selected address “the same basic phenomenon” (DeCoster, 2004: p. 6). The scope of the study was also meant to be broad enough such that “…….there is something to be gained by the synthesis that could not easily be obtained by looking at an individual study” (DeCoster, 2004: p. 6).
The researcher settled for various inclusion and exclusion criteria. The articles selected for the review should address the effects of blood transfusion on patients undergoing cardiovascular surgical procedures. The patients undergoing bloodless surgery in the studies selected should be Jehovah Witnesses. The patients should also be above 21 years of age, meaning pediatric patients below the age of 21 years will be excluded from the study. Below is a list of the inclusion and exclusion criteria used in the study:
- Articles must address cardiopulmonary by- pass surgical procedures
- Subjects used in the study must be 21 years of age and above
- The articles must address the issue of transfused versus non- transfused surgical procedures
- The non- transfused group in the articles must be made up of Jehovah Witnesses
- The articles must have been published not earlier than 2005
Searching for the Literature
Now that the research question and the hypothesis have been formulated, it was time now to search for literature that meets the criteria set out.
According to DeCoster (2004), once the boundaries of the meta- analysis have been set out, the researcher then needs to “locate all the studies that fit within those boundaries” (p. 7). This being the case, the researcher set out to locate as many studies addressing this topic as possible.
Formulating Key Terms
The process of locating the studies to be analyzed begun with the formulation of key terms which will be used in searching the articles. The key terms were formulated from the hypothesis to ensure that they are as relevant to the study as possible. The following are the key words that were used:
Table 1: Key Words used to Locate Articles
From the table above, it is obvious that the phrase “adult cardiopulmonary surgery” appeared in all the key terms used to search for articles. This is given the fact that this phrase was the main component of the search terms and as thus, it had to appear in all the key terms. The aim was to make sure that all the articles located revolved around cardiopulmonary surgery among adult patients. This means that from the word go, the researcher was able to eliminate articles addressing transfused and non- transfused surgery in other fields such as oncology, neural surgery among others. The inclusion of this phrase in all key terms also ensured that studies conducted among pediatric patients were not included.
It is also notable that the key terms above contain parentheses. According to DeCoster (2004), parentheses are used to ensure that the “computer is linking (the search) terms the way they are intended” (p. 8). This is especially so when one is locating articles using an electronic or computerized search engine. This is when the researcher is locating articles from online databases.
The use of the article “AND” was meant to help the computer link the search terms together. This means that the computer will locate articles which contain the phrases connected by this article.
Identifying the Search Engines to be Used
After formulating the key words, the researcher then went ahead and compiled a list of search engines and data bases that will be used to search for the articles. The researcher came up with an initial list of 15 medical databases. However, these were reduced to 8 after eliminating those databases which were believed to contain articles which are not relevant to this study. The final 8 databases are as listed below:
- PubMed
- MEDLINE
- NCBI
- WHOLIS
- AMED
- JSTOR
- Elsevier
- BioMed
The researcher settled on the 8 databases after it was felt that they contained articles relevant to this study. The researcher ran each of the four key terms in all the 8 databases. This gave rise to a large number of articles. It should be noted that some of the articles were irrelevant to the study and were discarded. The initial number of articles located and the final number of articles selected for each of the search engines is as listed below:
Table 2: Articles from Each of the Databases
From the initial 99 articles located from the search engines, the researcher selected only 58. The other 41 articles eliminated failed to meet the criteria set for the study.
Developing a Master Candidate List
According to DeCoster (2004), “……..many (articles) will turn up in several of your searches” (p. 7). This means that the researcher has to come up with a list where each of the articles located appears only once.
The search for literature in this study was no different. Among the 58 articles selected above, the researcher realized that many of them turned up in more than one database. The researcher came up with a master candidate list to make sure that each article appeared only once.
The master candidate list gave rise to 32 articles. These were the articles that the researcher took through the next stage of locating sources for this study.
Final Selection of the Articles
The researcher accessed and reviewed all the 32 articles selected. It was only 9.4 percent of these articles which remained at the end of this stage. After reading all of the articles, the researcher felt that all of them did not meet the inclusion and exclusion criteria fully. 3 articles were the ones which the researcher believed that they met all the inclusion and exclusion criteria. The three articles are analyzed in section 1.7 above.
Comparing and Contrasting the Three Articles
After settling for the three articles analyzed in section 1.7 above, the researcher then compared and contrasted them to identify the agreements and disagreements between the three. To this end, the researcher critically analyzed the objectives of the articles, the methodology adopted, the findings of the studies reported in the articles, the conclusions drawn by the various authors among other aspects. A critical analysis of these articles was then carried out within the context of the wider field of blood transfusion and cardiopulmonary bypass surgery. The aim here was to identify the link between the three articles and the rest of the studies in the field.
Potential Limitations and Weaknesses of the Research Methodology
According to DeCoster (2004), meta- analysis as a research methodology has several limitations. Some of them were manifest in this study. These are as analyzed below:
The Methodology Ignores the Study Quality
It is argued that meta- analysis usually fails to take into consideration the quality of the studies used. Instead, most researchers take into consideration the relevant of the study to their topic rather than the quality of the study or the standards followed.
The researcher in this case ensured that the articles included in this study were from credible authors who have published other peer reviewed articles. This ensured that the credibility of the articles was not compromised.
The Methodology uses Only Significant Findings of Other Studies
Critics of meta- analysis argue that the methodology cannot “draw valid conclusions because only significant findings are published” (DeCoster, 2004: p. 3). This is given the fact that most meta- analysis studies use only published articles. Relevant articles that may contain significant findings but which are not published are usually not included in the meta- analysis. The contribution of such studies is as a result ignored.
This researcher could well be accused of this bias. This is given the fact that all the three articles used in the study are published in medical journals. However, the researcher made use of other unpublished articles in this paper during the literature review.
Meta- analysis as a Methodology is Subjective
According to DeCoster (2004), opponents of this methodology argue that it is characterized by subjectivity thus affecting its credibility and quality of the findings. This is given the fact that the selection of the articles to be used in the study is subject to the discretion of the researcher.
To avoid this, the researcher made sure that the articles selected for the study are of high quality and from credible sources. The fact that the articles were published in peer reviewed journals is an indication of the fact that they are not as subjective as opponents of this methodology would like us to believe.
Results
Introduction
In chapter two, the researcher looked at the steps that were followed in conducting this research. The researcher looked at the steps that were followed in locating the articles used for the paper and the comparison made among the three articles and between the three articles and other studies in the field.
In this chapter, the researcher is going to present the results of the meta- analysis. To this end, the researcher will compare the objectives and purposes of the three articles, the methodologies adopted, the findings and the conclusions made.
Comparing the Three Articles
Starting from this juncture, the researcher is going to refer to the three articles used in this study as Article 1, Article 2 and Article 3. This is as opposed to providing the whole title of the article together with the authors. The three tags above will each correspond to the 3 articles as stated below:
Article 1
This will refer to Thesis Article 1 as indicated in section 1.7 above. This is the article titled How Good Blood Management Leads to Excellent Outcomes in Jehovah’s Witness Patients Undergoing Cardiac Surgery by Emmert et al. (2011).
Article 2
This will refer to Thesis Article 2 as indicated in section 1.7 above. The article is titled Comparison of Cardiac Surgery Outcomes in Jehovah’s Versus Non- Jehovah’s Witnesses by Stamou et al. (2006).
Article 3
This will be used in reference to Thesis Article 3 as it appears in chapter one of this paper. This is the article titled Bloodless Cardiac Surgery in Jehovah’s Witnesses: Outcomes Compared with a Control Group by Reyes et al. (2007).
A Comparison of the Objectives and Purposes of the Three Articles
The objectives of the three articles are summarized in the table below:
Table 3: Comparing Objectives and Purposes
Methodologies used in the Three Articles
Table 4: Methodologies
Pre- operative, Intra- Operative and Post- Operative Parameters
Each of the three articles analyzed for this study were found to have pre- operative, intra- operative and post- operative parameters. These are as indicated below:
Article 1
Parameters Preoperative : Age, Sex, History of smoking, diabetes, HTN, PAD, COPD, Elective surgery, Emergent surgery, redo surgery, Ace inhibitors, B blocker, Aspirin, Cabg on pump/off pump, Hemoglobin preop, Hematocrit preop, red blood cell count, platelets, INR preop, Fibrinogen
Parameters Intraoperative: Mortality, MI, Arrythmias, Duration of procedure, CPB time (min), Aortic Xclamp time, Ringers lactate, Blood products, bone wax
Parameters Postoperative: Mortality, MI, Stroke, Renal Failure, Arrhythmias, Re-exploration for bleeding, blood products, Hemoglobin at discharge, HCT at discharge, platelets, fibrinogen at discharge, Ventilation time, length of stay ICU, length of stay in hospital
Article 2
Parameters: stroke (p = 0.5), acute myocardial infarction (p = 0.6), new-onset atrial fibrillation (p = 0.106), prolonged ventilation (p = 0.82), acute renal failure (p = 0.70), and hemorrhage-related reexploration (p = 0.59), Mortality, length of stay. It is noted that the parameters for this study are similar to those in Emmert et al. (2011) above
Article 3
Pre- operative Parameters: all parameters compared JW vs. control group: Diabetes, Hypertension, Smoking, Dyslipidemia, COPD, Preoperative stroke Preoperative AF, Severe PH (>60 mm Hg), Ventricular dysfunction, hemoglobin, HCT
Preoperative parameters: AMI
Post- operative Parameters: Hemoglobin, Hematocrit, length of stay in hospital, length of stay in ICU, length of stay in hospital days total, repeat surgery due to bleeding, mortality, Renal Failure, Post op AF
Other Conditions Maintained in the Three Studies
Article 3
All the Jehovah Witnesses patients who requested for bloodless surgery (n= 59) were requested to sign a consent form. All subjects were taken through a laboratory workup before undergoing surgery. Depending on the recorded blood count, erythropoietin 300- 500 U/kg was administered every 24 hours for a period of 7 days for those patients with hematocrit <36 percent. The same was also administered 72 hours after surgery together with either oral or intravenous ferric therapy. Aprotinin or tranexamic acid was also used on all the 59 subjects during the operation. Cell saver systems were also used on all the 59 subjects during the operation (Reyes et al., 2007).
Article 1
A total of 16 Jehovah Witnesses were used for this study. These are the patients who underwent cardiac surgery between 2003 and 2008. The procedures performed on the patients were coronary revascularization (n= 6), valve (n = 6), combined (n= 1) and aortic surgery (n= 3) (Emmert et al., 2011: p. 183). For aortic surgery, two subjects had acute type- A dissection. Off pump surgery was carried out for those subjects who underwent cardiac bypass surgery (n= 5). Preoperative hematocrit was 42.8±4.7%. Preoperative Hb was 14.5±2 g/dl. Preoperative hematological stimulating treatment was also administered on those subjects with Hb< 12g/dl (n= 3).
Article 2
The study used subjects who underwent cardiac surgery between January 1990 and July 2004 (n= 20399). Cardiac transplantations, off- pump surgical procedures and pediatric patients (age <14 years) were not included in the research. Standard anesthesia and surgical techniques were used on all 20399 subjects. Extracorporeal circulation and myocardial protection methods were also utilized for all 20399 subjects. Anticoagulants were administered using 3 mg/kg heparin sulfate. This was meant to sustain an activated clotting time of ≥480 seconds.
Findings Made in the Three Articles
Article 1
The mean age of the subjects in this study was 63± 17 years. The preoperative EuroSCORE for all the patients was 5.7±1.9. Preoperative platelets were 255± 55×103/µl.
All the subjects survived the operation. No major complications were reported despite the fact that none of the patients received blood products. The Cell Saver system with a transfused volume of 474±101 ml was used. Ringer’s Lactate (873±367 ml) and HES 6% (700±388ml) were used as synthetic plasma substitutes (Emmert et al., 2011). Bone wax, fibrin glue and hemostaticas were also used routinely.
The scholars found that decrease in Hk and Hb were the lowest during off- pump surgery (Emmert et al., 2011). This is as compared to other forms of CPB (25±9% vs. 33±6%; P=0.01 and 22±9% vs. 31±6%; P=0.04) (Emmert et al., 2011: p. 186). It was also found that decrease in the level of platelets was also greatly reduced (20±12% vs. 43±14%; P=0.01). The follow-up duration in this study was 52±34 months. During this period, one of the subjects died as a result of non-cardiac complications. The other 15 patients were alive and in good clinical condition. No MACE was reported among the 15. Recurrent symptoms were also not present.
Article 2
The scholars found no significant differences between Jehovah Witnesses and other patients when controlled for post- operative risk factors. According to Stamou et al. (2006), “no significant differences were identified in unadjusted stroke (p=0.5), acute myocardial infarction (p=0.6), new-onset atrial fibrillation (p=0.106), prolonged ventilation (p=0.82), acute renal failure (p=0.70) and hemorrhage related reexploration (p=0.59) rates between the two groups” (p. 1223).
The postoperative mortality rates, postoperative length of stay and intensive care unit stay between the two groups of patients was similar (Stamou et al., 2006).
Article 3
The researchers found that the clinical characteristics of the 2 sets of patients were comparable. It was however found that Hb and Hk levels were higher in Jehovah Witnesses both before and after cardiac surgery (Reyes et al., 2007). Before surgery, Hb and Hk levels among this group was 13.6 g/dL vs 12.9 g/dL; P=.01, and 40.7% vs 39%; P=.09. After the operation, the Hb and Hk levels were 11 g/dL vs 10 g/dL; P=.003, and 34.2% vs 30.7%; P=.001 (Reyes et al., 2007). It was also noted that JW patients reported less bleeding as compared to the control group. Intubation was also reduced as well as post operative stay in intensive care and the hospital. However, there were no significant differences between the two groups as far as postoperative complications and mortality was concerned (Reyes et al., 2007).
A Comparison of the Conclusions Made in the Three Articles
Discussion of Results
Some similarities can be drawn between the three articles analysed in this study. One of them is the objectives of the studies. All the articles addressed clinical outcomes among non- transfused cardiac patients taking Jehovah Witnesses as representatives of the non- transfused patient category. However, two of the studies compared the outcomes in JW witnesses with those of other patients receiving blood products while one of the studies addressed JW patients alone. Article 1 addressed the issue of good patient blood management protocols and patient outcomes among Jehovah Witnesses without comparing the results with those of non- Jehovah Witnesses. However, Article 2 and Article 3 compared the outcomes among JW with those among non- Jehovah Witnesses.
Article 1 used 16 JW patients operated on between 2003 and 2006. Article 2 made use of 49 JW and 196 non- JW operated on between January 1990 and July 2004 (N=245). Article 3 used 59 Jehovah Witnesses and 59 non- Jehovah Witnesses (N= 118). This means that the current study made use of data collected from 379 patients (N=379) made up of 124 JW and 255 non- JW.
The findings and conclusions made in the three papers are also comparable. Article 1 concluded that good patient blood management practices improve the outcomes of the patients after surgery. Article 2 concluded that blood conservation protocols during bloodless surgery made it possible to achieve patient outcomes comparable to transfused surgery outcomes. Article 3 concluded that bloodless surgery can give rise to patient outcomes which are similar to those observed in transfused surgery provided that patient’s clinical characteristics remain constant.
Taken as one, the findings and conclusions drawn from the three articles points out to the fact that bloodless surgery can give rise to patient’s outcomes similar to those achieved during transfused surgery. This is provided that the perfusionists, the nurse and other professionals involved in the surgery adhere to certain practices. These are for example good patient blood management protocols, controlling for patient’s pre-operative clinical characteristics and adhering to blood conservation protocols.
This meta- analysis found that blood transfusion is not necessary during cardio-pulmonary bypass surgery. The perfusionist can reduce cases of unnecessary blood transfusions by adhering to good patient blood management practices and observing blood management protocols.
The findings of the meta-analysis addressed the research hypothesis formulated in chapter 1 above. The hypothesis read: Adult cardiac surgical patients with no blood transfusion during cardiopulmonary by-pass surgery have significantly lower morbidity rates than patients receiving donated blood. The findings of this meta-analysis proved this hypothesis to be true. It was found that JW patients who received no blood transfusion had significantly lower morbidity levels as compared to those patients who received blood transfusion. For example, Emmert et al. (2011) found that JW had no post-operative MACE or any other recurrent symptoms that would have called for further post-operation intervention. Reyes et al. (2007) found that non- transfused patients (JW) reported less morbidity rates given that they recorded reduced 24 hours bleeding, shorter hospital stay and mechanical ventilation.
The findings of the three articles and consequently the findings of the current study are consistent with findings made by other scholars in the field. For example, when looking at the link between Intraoperative blood transfusion and post-operative outcomes in patients undergoing non-cardiac surgery, Laurent et al (2011) Intraoperative blood transfusion increased mortality rate among patients. Morbidity rates characterised by complications such as thromboembolic were also higher in patients receiving blood transfusions. Ranucci et al (2010) concluded that patients undergoing transfused cardiopulmonary bypass surgery had increased morbidity levels characterised by complications such as renal failure, anemia among others.
Conclusions
This meta-analytic study sought to find out whether it is a fact that adult cardiac surgical patients with no blood transfusion during cardiopulmonary bypass surgery have significantly lower morbidity levels than patients receiving donated blood. The study addressed this issue using Jehovah Witnesses as the group of patients undergoing bloodless surgery. The outcomes of these patients were compared with that of patients undergoing transfused cardiac surgery. It was found that patients undergoing bloodless cardiac surgery had less morbidity rates as compared to transfused patients. The researcher located three articles addressing this issue and analysed them critically.
The findings of this study raise a very significant question. If non-transfused patients have better outcomes as compared to transfused patients, why can’t perfusionists adopt bloodless surgery for all cardiac surgery patients? Given that the hypothesis of this study was supported, it is noted that then no or little donor blood should be used if associated with comorbidities. This being the case, the perfusionist then needs to ask themselves the question: “at what point is the HCT too low such that it loses its effect?”
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