General Surgery, University of Texas Southwestern, Dallas, USA, United States
Background/Case Studies: Preoperative anemia is an under-recognised yet prevalent condition that affects surgical outcomes in low middle-income countries (LMICs). Despite the high prevalence of preoperative anemia, the definition, management, and its effect on surgical outcomes remains unclear. The consequences of anemia are specifically significant in LMICs since the access to safe blood products and critical care support is limited. This review aims to understand the impact of preoperative anemia on surgical delay, transfusion needs, hospital stay, postoperative complications, and mortality.
Study
Design/Methods: A scoping review was conducted in accordance with PRISMA guidelines. The review protocol was registered in the PROSPERO database (Registration No: CRD420250654109). Databases including PubMed, CINAHL, Web of Science, and Embase were searched for cohort, case-control, cross-sectional studies, and randomized controlled trials that reported at least one outcome in the setting of preoperative anemia. Outcomes that were considered included postoperative complications, transfusion requirement, length of stay, mortality, discharge time, and readmission. Title and abstract screening was performed on 1513 studies after which 1444 were excluded. Sixty-nine full-text articles were assessed, of which 38 were excluded for reasons including wrong setting (n=13), wrong outcomes (n=7), wrong study design (n=7), no surgical intervention (n=5), wrong patient population (n=4), pediatric-only population (n=1), wrong comparator (n=1), and no full text (n=1). In total, 30 studies were included. Data were extracted using a pre designed data extraction template and thematic analysis of the data was carried out (as described in Figure A).
Results/Findings: Among the 30 included studies, 63% (19/30) explicitly defined anemia, with variations in the hemoglobin thresholds. 20% (6/30) of the studies stratified anemia by severity (mild, moderate, severe). 10 studies reported the treatment of anemia with only 1 reporting the type of blood products transfused. 20% of the studies reported surgical delays attributed to anemia with a mention of delay due to preoperative correction. None of the included studies had a quantitative correlation between preoperative anemia and postoperative outcomes such as infection rates, wound healing, length of hospital stay, or readmissions.
Conclusions: This review highlights major gaps that exist in literature on preoperative anemia in LMICs. Data on surgical delays due to preoperative anemia and functional outcomes are minimally reported. Specific emphasis must be placed on standardized diagnosis, detailed reporting of treatment, and association with postoperative outcomes to highlight the burden of preoperative anemia specifically in LMICs.
