The association between preoperative anaemia and surgical mortality and morbidity in South African surgical patients

• Main Author: Marsicano, Daniela
• Other Authors: Hauser, N
• Format: Dissertation
• Language: English
• Published: Faculty of Health Sciences 2020
• Subjects: Anaesthesiology
• Online Access: http://hdl.handle.net/11427/31104

Background: In high-income countries, preoperative anaemia has been associated with poor postoperative outcomes. To date, no large study has investigated this association in South Africa. The demographics of South African surgical patients differ from those of the European and Northern American surgical patients where the preoperative anaemia data are derived. These associations between preoperative anaemia and postoperative outcomes are therefore not necessarily transferable to South African surgical patients. Objectives: The primary objective was to determine the association between preoperative anaemia and in-hospital mortality in South African adult noncardiac, non-obstetric patients. The secondary objectives were to describe the association between preoperative anaemia and i) critical care admission, and ii) length of hospital stay, and to describe the prevalence of preoperative anaemia in adult South African surgical patients. Methods: We performed a secondary analysis of the South African Surgical Outcomes Study (SASOS) – a large, prospective, observational study of patients undergoing in-patient noncardiac, non-obstetric surgery at 50 hospitals across South Africa over a one-week period. To determine whether preoperative anaemia is independently associated with mortality or admission to critical care following surgery, we conducted a multivariate logistic regression analysis, which included all the independent predictors of mortality and admission to critical care identified in the original SASOS model. Results: The prevalence of preoperative anaemia was 1727/3610 (47.8%). Preoperative anaemia was independently associated with in-hospital mortality (odds ratio (OR) 1.66, 95% confidence interval (CI) 1.06-2.60, p=0.028) and admission to critical care (OR 1.49, 95% CI 1.08-2.05, p=0.015). Conclusion: Almost 50% of patients undergoing surgery at government-funded hospitals in South Africa had preoperative anaemia, which was independently associated with postoperative mortality and critical care admission. These numbers indicate a significant perioperative risk, with a clear opportunity for quality improvement programmes which may improve surgical outcomes. Long waiting lists for elective surgery allow time for assessment and correction of anaemia preoperatively. With a high proportion of patients presenting for urgent or emergency surgery, it behoves perioperative clinicians in all specialities to educate themselves in the principles of patient blood management.