Blood Ordering And Utilisation Practices For Elective Thoracic And Cardiovascular Surgery At Kenyatta National Hospital: A Step Towards Establishing A Maximum Surgical Blood Ordering Schedule.

Abstract

ABSTRACT: Introduction: Blood is a valuable resource and is vital in the safety of major operations. Its use for such surgeries should be guided by evidence-based protocols and guidelines. This is however not the case at the Kenyatta National Hospital where blood ordering for peri-operative use, like in many other institutions in Kenya and in Africa, has been based on habit, past experiences, and on the subjective anticipation of blood loss. This highlights the need for development of such protocols, an example of which is the Maximum Surgical Blood Ordering Schedule (MSBOS). This schedule, if developed for thoracic, cardiac and vascular surgeries, which are the largest consumers of blood, would minimise blood wastage, costs of its production and lead to a reduction in theatre cancellation rates for these procedures. Objectives: This study was carried out to determine the blood ordering and utilisation practices for elective thoracic and cardiovascular surgery at the Kenyatta National Hospital. Factors influencing these practices were also determined. Development of a Maximum Blood Ordering Schedule (MSBOS) was a secondary objective. Methods: This was a cross-sectional descriptive study carried out on patients undergoing thoracic, cardiac, and vascular surgery at the Kenyatta National Hospital from June to November 2017. Pre and intra-operative data was recorded from consecutively recruited participants who gave an informed consent and a questionnaire was filled. Amount of blood requested and transfused was recorded and the Cross-match to Transfusion ratio, Transfusion Probability and the Transfusion Index calculated. This aided in the tabulation of an MSBOS. A t-test was used to compare the means and multiple regression analysis done to predict blood utilisation from the clinical variables. A significance level of 0.05 was set. Results: A total of 52 study participants were recruited into the study with a mean (SD) age of 42.60 (15.66). 7 procedures were recorded; 3 thoracic, 3 vascular and 1 cardiac. Females had more pints cross-matched (p=0.016) and underwent longer procedures (p=0.005) than males. They xii also had more pints transfused (p=0.016), which was however not statistically significant after multivariate regression analysis (p=0.148). Length of procedure significantly predicted blood loss (p <0.005) and ultimately pints of blood transfused (p <0.005). The overall C/T ratio was 2.1:1 with thoracic procedures having the highest C/T ratios. The transfusion probability and transfusion index were 59% and 1.3 respectively. Conclusion: This study shows that there was appropriate blood utilisation for cardiac, vascular and thoracic surgery at the Kenyatta National Hospital though this differed for individual procedures. Age, gender, weight and preoperative haemoglobin didn’t affect blood utilisation practices while longer procedures led to more blood loss and more transfusions. Finally, we can conclude that at the Kenyatta National Hospital, 5 units of blood are needed for single cardiac valve replacement, 3 units for AAA repair, 2 units for pneumonectomy, and 1 pint each for oesophagectomy and decortication. Only a G & S would be needed for AV Fistula and venous stripping. This would ensure appropriate blood use.