Prevalence of pre-operative anemia and its implication for patient blood management in a Nigerian Hospital
Authors: Kalu Queeneth , Usoro Nathaniel , Etta Otu , Eshiemomoh Roseline , Enabulele Joseph 
Published: November 2022

Objectives:
Pre-operative anemia is common in Sub-Saharan Africa including Nigeria. Anemia is a known risk factor for blood transfusion. In our hospital, like many others, patients are usually admitted a day before elective surgeries and the default treatment for anemia by most surgeons and anesthetists is allogenic blood transfusion. Anemia and blood transfusion are independently and synergistically associated with complications and undesirable outcomes. Patient blood management (PBM) is gaining popularity and has been advocated by the World Health Organization (WHO) for member countries to adopt as a means of improving patient outcomes. There is currently no research from the University of Calabar Teaching Hospital highlighting the prevalence of pre-operative anemia. This research was aimed at filling this gap and also presenting a baseline for comparison as the hospital strives to implement the three pillars of PBM strategies: Manage anemia, minimize blood loss and harness tolerance to anemia to improve patient outcomes.

Material and Methods:
All surgical patients who consented to the study were recruited prospectively. Patients who had no pre-operative hemoglobin (Hgb) or packed cell volume (PCV) recorded were excluded from the study. Demographic data, type of surgery, and pre-operative PCV levels were documented. Anemia was defined using the WHO standard as PCV <39% (Hgb 13.0 g/dL) in men and <36% (Hgb 12.0 g/dL) in women. Data were obtained about transfusion at the end of surgery. Surgeries were categorized into general, orthopedic, obstetric, gynecological, urologic, pediatric, ear, nose, throat/maxillofacial, burns and plastic unit (BPU), neurological, and thoracic. The information was entered into SPSS version 20. Data were cleaned and analyzed. The statistical significance was placed at P < 0.05. Results are presented as tables, chats, and histograms.

Results:
A total of 237 patients were recruited with a mean age of 37.30 ± 19.05. More of them were females (54.0%) and a higher proportion of them (64.6%) had elective surgery. The categories of surgeries were predominantly general surgical (24.9%) and gynecological (21.9%) followed by orthopedic (17.7%), ENT/maxillofacial (9.3%), urologic (8.0%), and obstetric (7.2%) cases. The rest were neurosurgical (3.4%) and pediatric surgical (2.1%) cases. The overall prevalence of anemia was found to be 54.9%. The mean pre-operative PCV was 34.90 ± 7.37%. The highest proportion of pre-operative anemia was found among the pediatric surgical cases (80.0%) followed by the urologic (68.4%) and neurosurgical cases (62.5%). The prevalence of pre-operative anemia among the different surgical patients was gynecological (46.2%), general surgical (45.8%), obstetric (41.2%), ENT/maxillofacial (40.9%), and orthopedic (38.1%) cases. The lowest proportion of pre-operative anemic patients was found among the thoracic (25.0%) and Burns and Plastics (11.1%) cases. Most of the patients (86.5%) were not transfused intraoperatively. Whereas 20% of the anemic patients were transfused; only 5.6% of the non-anemic ones needed a blood transfusion.

Conclusion:
Pre-operative anemia remains prevalent in our environment and anemia is a risk factor for a blood transfusion which carries both risk and cost implications. PBM has as its first pillar the management of anemia. This pre-emptive approach to allogeneic blood transfusion avoidance is aimed at improving patient outcomes. Prevention and treatment of pre-operative anemia will be beneficial not just to the patients but to all healthcare stakeholders.