Association of preoperative anemia and increased risk of blood transfusion and length of hospital stay in adults undergoing hip and knee arthroplasty: An observational study in a single tertiary center

BACKGROUND AND AIMS: Anemia is a common feature in patients presenting for major elective surgery, and it is considered an independent risk factor associated with adverse outcomes. Although several studies suggest that preoperative anemia is associated with poor outcomes after elective orthopedic surgery, data are still scarce in middle‐ and low‐income countries where this problem may be even greater. The objective of this study was to evaluate the impact of preoperative anemia in clinical outcomes in patients submitted to hip and knee arthroplasty in a single tertiary hospital. METHODS: Medical records of 234 adult patients submitted to knee and hip arthroplasty from January 2018 to July 2020 were retrospectively reviewed. Patient's demographics (ie, age and gender), pre‐ and postoperative hemoglobin level (Hb), allogeneic red blood cell (RBC) transfusion, intensive care admission, length of hospital stay, hospital readmissions, and mortality up to 30 days after the surgery were analyzed. Outcomes were evaluated according to preoperative anemia status based on World Health Organization (WHO) criteria. RESULTS: Mean age was 70 years with a slight female predominance (57.6%). The prevalence of anemia was 30.7% (72/234) being more prevalent in female (33.3% vs 26.7%). Preoperative anemia was significantly associated with greater rate of blood transfusion (34.5% vs 5.6%; P = .001), prolonged length of hospital stay (6.48 days vs 3.36 days; P = .001), and higher rate of intensive care unit admission (47.2% and 29.6% P = .009). Preoperative anemia had no effect on 30‐day readmission and mortality for both males and females. CONCLUSIONS: Our retrospective study demonstrated that preoperative anemia is a common problem among orthopedic patients and is associated with increased transfusion risk and worse outcomes. Strategies to identify and treat anemic patients before elective surgery are critical to improving clinical outcomes.