The benefits of mechanical improvements in cardiopulmonary bypass - Thesis Proposal Example

The benefits of mechanical improvements in cardiopulmonary bypass Introduction Advances in medical mechanics and functions are designed to not only create ease for the medical practitioners but to improve overall patient health care and that includes their physical, psychological and sociological well being. Cardiovascular surgery is one of the most common procedures required in medical industry, required by almost half a million people in the United States alone each year. Currently, the surgery has a relatively low mortality and risk rate thanks to the development of advanced techniques in the past 20 years including advances in biomaterials, manufacturing, computer microsystem technology, and electronics (Jameel et al, 2009). Cardiopulmonary bypass (CPB) is a system that takes over the basic functions of the heart and lungs, that is circulation of blood and the providing oxygen to cellular bodies, during surgery. This allows the cardiac operation to take be performed in a less chaotic and stationary environment thus reducing chances of error. During the procedure, the blood is gravity drained to a reservoir, it is then oxygenated and returned to the arterial system via a pump. One of the main concerns for physicians is the damage that is sustained by the blood and blood cells during friction as it is being propelled from the pump. The commonly used rolled pumps utilize a basic mechanism with tubing lined along a raceway with rollers massaging the tubing to propel the blood forward. This style of pump requires the clinician to keep the occlusion balanced at a level that ensures adequate forward blood flow with minimal damage the fragile blood cells inside the tubing. Roller pumps have been found to cause shear stress in blood that can lead to haemolysis, realease of vasoactive substances and spallation which is a breakdown in the tubing wall. Hemolysis and the corresponding increase in plasma free hemoglobin are severely detrimental to the patient outcome and prolong the patients’ recovery following cardiac surgery utilizing cardiopulmonary bypass. However, there has been some decrease in the occurrence of these risks by the utilization of centrifugal pumps that were specifically developed to eliminate intermittent tubing occlusion. Research has been done to provide evidence that the damage to red blood cells, platelets, and plasma proteins is minimized with the use of centrifugal pumps as compared to the common roller pumps but the answers remain inconclusive despite the mass volume of data available on the topic. While in recent years there has been an uptake in the use of centrifugal pumps specially during extended surgeries; the lack of supporting and concrete evidence for the benefits of the system has restricted the complete conversion away from roller pumps. Problem Statement There is a research gap in the data and conclusions available for the comparative advantages of using Centrifugal pumps against roller pumps during Cardiopulmonary bypass and this gap is limiting the benefits and increase in quality care for the patients. As long as medical practitioners cannot be sure of the advantages of utilizing these pumps, the necessary financial and research investment cannot be provided for the complete conversion of the CPB techniques. This research will focus on meta- analysis of the existing material on the topic in the attempt to provide comparative and conclusion remarks on the advantages of centrifugal pumps and suggest the future direction of the technology for CPBs. Previous researches will be evaluated using statistical tools as well as qualitative content analysis to gather insights and points of parity for the research making this is a triangulation approach. The following hypothesis and questions will be the guiding points for the research: Hypothesis The stance that the researcher is taking on the question of the current improvements in CPB technology is that: “Patients receive increased benefits during cardiac procedures as well as during recovery period from the use of Centrifugal pump technology in Cardiopulmonary bypass” Research questions The content and qualitative analysis of the research will attempt to answer the following questions: Has cardiac patient’s care and recovery time has increased in quality after the introduction of centrifugal pumps in the process? What is the overall perception and reaction of medical practitioners towards the technique? Is more research required to compare the CPB techniques available at this point in time? Are more advanced techniques required in CPB before patient risk can be minimized? What should be the focus of researchers in the field of CPB and cardiac surgery in the coming years? Methodology As a meta-analysis all the data for the research will be secondary in nature, acquired from peer reviewed medical journals and researches. The inclusion criteria for the analysis has been limited to randomized controlled studies (as they are considered the gold standard in clinical trials) available and originally written in the English language. Non-randomized studies will be reviewed and possibly referred to if sample size and strength of the study prove significant but will not be the focus of the study. Only Research papers written in the past 2 years will be considered as they will provide the latest information and updated reviews of the technology; studies conducted before 2011 will be referred to provide historical background and edifications. All studies included in analysis must include two of the following measurements: Interleukin 6, Interleukin 8, Blood product transfusions (RBC, FFP, Platelets), Complete Blood Count, White Blood Count, Platelet Count, Hct, Hb, Plasma Free Hemoglobin. Research sources/ Data Collection Initial searches will be conducted through the EbscoHost portals MEDLINE and CINAHL using the following keywords : “centrifugal vs. roller blood pump; centrifugal vs. roller pump; hemolysis during cardiopulmonary bypass; hemolysis caused by blood pump; inflammatory response caused by cardiopulmonary bypass; blood pump in cardiac surgery”. Reference review of works cited by initial querys as well as review of works cited in current student text will be consulted for further data points. Index of Hemolysis will be consulted as well to guide the research. Studies conducted on pediatric population will be excluded from the analysis due to fragility of blood cells, although literature will be reviewed and possibly referred to if deemed appropriate, and studies conducted in non-human patients will be excluded due to the abundant qualifying studies, which have been conducted on actual patients. Data from the researches will be collated and coded for efficient analysis, using a basic spreadsheet format. A preliminary table has already been constructed for the purpose but it may be changed further as the literature review goes ahead: Research Title Research Year First Author Sample Size Common Data points Subject (Human/ Non-Human) Statistical tools used Results and Remarks Cited By Using such a spreadsheet will allow the researchers to correctly categorize prior researchers and select the ones for statistical analysis. All will be used for the qualitative part of the study. Accompanying accounts will provide explanations for the common data points to be used and highlight the landmark studies. Any of the studies which have been cited by at least 20 other authors will be considered as the landmark studies. The references for the initial literature review are present in the ‘references’ section. Statistical analysis The conclusions of the selected studies will be quantified using the pre-decided common data points to gauge the advantages/ success of centrifugal pumps. These data points will then be analyzed using a ‘Two independent samples t-test’ that will compare the mean of the dependant variable (patient health/outcome) for two independent groups (i.e the use of roller pumps or the use of centrifugal pumps). The confidence interval will be kept at 90% of significance given the erratic nature of the data collected. Other tools like One way ANOVA will also be considered if enough data points have been collected . Discussion While time constraints make this method of research efficient given the vast debate already going on at the topic, the researches accept that it is possible that more primary studies will be required before a conclusive answer can be given. However, a meta analysis can also help unearth the answers that Medical practitioners and perfusionists need to advocate to the manufactures and FDA to invest in the development and authorize use of blood pumps that better serve the patient and cause no harm. REFERENCES: Albert T. Cheung, M. G.-S. (2007). Cardiopulmonary Bypass, Hemolysis, and Nitroprusside-Induced Cyanide Production. International Anesthesia Research Society, 105 (1), 29-33. Andreas Keyser, M. K. (2011). Prospective Randomized Clinical Study of Arterial Pumps Used for Routine on Pump Coronary Bypass Grafting. Artificial Organs, 35 (5), 534-542. Pelosi, A., Anderson, L.K., Paugh, J., Robinson, S., and Eyster, G.E., (2013). 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Bio-Medical Materials and Engineering, 23, 37-47. Sebastian Holinski, M. B. (2013). Effect of Different Pump Heads for CPB on Early Cognitive Outcome after Coronary Artery Bypass Surgery. Annals of Thoracic and Cardiovascular Surgery, 19, 273-278. Silva, C D., et al., (2013). In Vivo Evaluation of Centrifugal Blood Pump for Cardiopulmonary Bypass—Spiral Pump. Artificial Organs, HYPERLINK "http://onlinelibrary.wiley.com/doi/10.1111/aor.2013.37.issue-11/issuetoc" Volume 37, Issue 11,  pages 954–957, . Read More