Study of the patterns of utilisation of blood and blood products, and (b) the status of subgroups of blood group A (A1) and A 2) at the Kenyatta National Hospital

Abstract

This study aimed at assessing the demand for and utilisation of blood by different wards at the Kenyatta National Hospital. Five hundred and five requests for blood received at the hospital's blood transfusion centre between July and November, 1990 were studied. The ratio of units of blood crossmatched for a patient to units transfused into the patient (crossmatch/transfusion ratio) was used to assess blood utilisation. For the paediatric requests, the amount of blood issued to a patient and the amount actually transfused into the patient was also considered. Approximately thirty seven per cent (37.h%) of the requests were from the surgical wards; 3**.9% were from the obstetric/gynaecologic wards and the rest (27.7%) were from general medical wards (adult and paediatric). Blood was crossmatched for 51.3% of those requesting for it. The paediatric wards showed the lowest crossmatch/ transfusion (C/T) ratio of 1.1/1 while the surgical and medical wards had C/T ratios of 2.0/1 and 1.5/1 respectively. In the paediatric wards, 61.7% of the patients were transfused with less than 500mls of blood although each was issued with a 500mls of blood pack. The findings show that blood transfusion service is not adequate to meet the demands of the hospital. Surgical patients have the highest demand for blood. However, by comparing C/T ratios, the medical wards show better blood utilisation rates than the surgical wards. There are some surgical procedures which are associated with such low transfusion rates that pre-operative cross- matching for 2 units of blood may not be warranted. The 500 ml blood packs issued to paediatric patients are often not fully utilised and any blood remaining in the pack is wasted. b) the subgroups of blood group A1 and A2 are the most common. These subgroups are identified by mixing the cells with anti-A. serum (absorbed B) or anti-A. lectin obtained from the seeds of dolichos biflorus. In this study, three hundred and thirty two blood group A and forty four hundred group AB (total three hundred and seventy six) samples received at the hospital's blood transfusion centre were subgrouped into A1 and A2 using commercial anti-A1 prepared from the lectin Dolichos biflorus. Subgroup was found to comprise BU.3% of group A and 79.5% of group AB samples. The ratios of in blood groups A and AB were found to be 5.A/1 and 3.9/1 respectively. The apparent difference in the ratio of A1/A2, in blood groups A and AB was not statistically significant. This result is in contrast to the findings of other investigators who have reported a higher proportion of non-A1 antigens. It is recommended that a survey involving a larger population should be undertaken to verify these findings. These 2 studies, though different, are both related to transfusion medicine. Because the study on blood utilisation consisted entirely of data collection and analysis, the second study was chosen to engage the author in a practical aspect of blood transfusion which is a requirement for this course.