Preoperative anaemia in patients undergoing open intra-abdominal surgery at a South African tertiary hospital

Abstract

Background: The prevalence of preoperative anaemia (PA) in mixed surgical populations is as high as 47.8%. PA in mixed surgical populations is associated with increased postoperative mortality (PM). It is likely that the prevalence of PA and the associated risk of PM might be higher in open intra-abdominal surgery (OIAS) populations, such as laparotomy patients, due to the underlying disease pathologies in this group. An investigation of PA in OIAS patients can inform future improvements in the perioperative management of this high-risk surgical group.
Method: This was a sub-analysis of data from a pre-existing registry of 435 laparotomy patients who attended a South African tertiary hospital. The registry collected data on preoperative haemoglobin (Hb), patient characteristics, and PM. Identified PA was graded according to World Health Organization definitions. Established mean red cell volume (MCV) thresholds were used for the morphological classification of PA.
Results: The prevalence of PA was 71.0% (95% confidence interval [CI]: 66.8–75.3%). Overall, PA was associated with a three-fold higher risk of PM (odds ratio 3.35, p < 0.001). Postoperative mortality was higher in patients with moderate and severe anaemia than in those without anaemia, while there was no difference in PM between patients with mild anaemia and non-anaemic patients.
Conclusion: PA is common in OIAS patients and is associated with increased PM. Identification of OIAS patients with PA, and appropriate preoperative management of these patients is recommended.