SRS179 - Could we use the ASA grade as a predictor to identify patients who would benefit from routine postoperative blood tests after primary total joint replacement?

Abstract Aims To evaluate the necessity of routine postoperative blood tests after primary total joint replacement and explore the use of ASA grade as a predictor to identify patients who would benefit from such tests. Reducing unnecessary tests may shorten hospital stays, lower costs, and support the shift toward day-case joint replacement. Methods This retrospective review included 1200 consecutive primary total joint replacements at our hospital. Data collected from electronic records included demographics, type of surgery, ASA grade, and pre-/postoperative blood test results (haemoglobin, sodium, potassium, renal function). Interventions related to abnormal postoperative tests—such as AKI management, electrolyte correction, or blood transfusion—were documented. Results A statistically significant association was observed between need for postoperative intervention and:Higher ASA grade (P = 0.016)Preoperative anaemia (P = 0.042)Chronic DOAC use (P = 0.012)Serum sodium (P = 0.023)43 patients required postoperative intervention triggered by abnormal blood tests.Postoperative anaemia (n = 17):10 required blood transfusion (90% were anaemic preoperatively)7 managed with active monitoringHyponatraemia (n = 24):23 monitored; 1 symptomatic case treatedAcute kidney injury (n = 2):Managed with IV fluids and diuretic discontinuationAll interventions occurred in ASA III–IV patients; none in ASA I–IIPostoperative Hemocue ≥100 g/L reliably predicted no intervention requirement Recommendations ASA I–II patients are unlikely to need postoperative blood tests. ASA III–IV patients may benefit from routine postoperative testing. A recovery room Hemocue ≥100 g/L may eliminate the need for further blood tests