The association between preoperative anemia and postoperative morbidity in pediatric surgical patients: A secondary analysis of a prospective observational cohort study

Abstract

Background The prevalence of anaemia in the South African paediatric surgical population is unknown. Anaemia may be associated with increased postoperative complications. We are unaware of studies documenting these findings in patients in low‐ and middle‐income countries (LMICs). Aim The primary aim of this study was to describe the association between preoperative anaemia and 26 defined postoperative complications, in noncardiac paediatric surgical patients. Secondary aims included describing the prevalence of anaemia and risk factors for intraoperative blood transfusion. Method This was a secondary analysis of the South African Paediatric Surgical Outcomes Study, a prospective, observational surgical outcomes study. Inclusion criteria were all consecutive patients aged between 6 months and <16 years, presenting to participating centres during the study period who underwent elective and non‐elective noncardiac surgery and had a pre‐operative haemoglobin recorded. Exclusion criteria were patients aged <6 months, undergoing cardiac surgery, or without a preoperative Hb recorded. To determine whether an independent association existed between preoperative anaemia and postoperative complications a hierarchical stepwise logistic regression was conducted. Results There were 1094 eligible patients. In children in whom a preoperative Hb was recorded 46.2% had preoperative anaemia. Preoperative anaemia was independently associated with an increased risk of any postoperative complication (odds ratio 2.0, 95% confidence interval: 1.3 to 3.1, p=0.002). Preoperative anaemia (odds ratio 3.6, 95% confidence interval: 1.8 to 7.1, p<0.001), was an independent predictor of intraoperative blood transfusion. Conclusion Preoperative anaemia had a high prevalence in a LMIC and was associated with increased postoperative complications. The main limitation of our study is the ability to generalise the results to the wider paediatric surgical population, as these findings only relate to children in whom a preoperative Hb was recorded. Prospective studies are required to determine whether correction of preoperative anaemia reduces morbidity and mortality in children undergoing noncardiac surgery.