The effect of preoperative anemia on perioperative outcomes among patients undergoing emergency surgery: A multicenter prospective cohort study

Introduction: Preoperative anemia is a common finding among surgical patients. It is associated with an increased risk of perioperative morbidity and mortality. Outcomes among emergency surgical patients are not established. This study aimed to assess the effect of preoperative anemia on perioperative outcomes among patients undergoing emergency surgery in selected Southern Ethiopia governmental teaching hospitals, Southern Ethiopia, 2022.

Method: A multicenter prospective cohort study was conducted. Data were collected at selected hospitals, after obtaining ethical approval from the institutional review board. Descriptive statistics, cross-tabulation, and multivariable binary logistic regression analysis were performed. A P-value less than 0.05 were taken as statistically significant.

Result: A total of 200 patients who underwent emergency surgery were grouped into the anemia group (100 patients) while the rest were in the non-anemia group. There was no statistically significant difference between the groups regarding socio-demographic and intraoperative patient characteristics. Based on multivariate logistic regression, anemia group had a significant risk of perioperative transfusion requirement (Relative Risk (RR) = 4.030, p < 0.001), developing postoperative complications (RR = 1.868, p = 0.017), occurring in-hospital mortality (RR = 5.763, p = 0.045), prolong the length of hospital stay (RR = 4.028, p < 0.001), and requiring postoperative intensive care unit admission (RR = 6.332, p = 0.003) compared with non-anemia groups.

Conclusion: Preoperative anemia was associated with a higher rate of perioperative transfusion requirements, along with increased postoperative complication, increased in-hospital mortality, increased Intensive Critical Care Unit admission rate, and prolonged length of hospital stay. We recommend adequate preoperative assessment and correction of hemoglobin concentrations to normal values to improve surgical outcomes and reduce complications.