Title : Raising the threshold: Safety evaluation of ASA III patients undergoing elective hip and knee replacement without intensive care backup
Abstract:
Background: Many ring-fenced elective orthopaedic hubs exclude American Society of Anesthesiologists (ASA) III patients because of limited on-site intensive therapy unit availability and reduced in-house medical cover. This retrospective service evaluation assessed whether ASA III patients can safely undergo elective primary hip and knee arthroplasty in a ring-fenced orthopaedic unit without routine intensive care backup.
Methods: A total of 536 consecutive elective primary total hip and knee replacements performed between March 2021 and August 2024 were reviewed. Primary outcomes were intensive care admission and non-orthopaedic postoperative medical review. Secondary outcomes were length of stay, transfusion and wound complications. Outcomes were compared across ASA I-IV, focusing on ASA III versus ASA I-II. Logistic regression was performed using an online SPSS statistics platform.
Results: Of 536 procedures, 282 (52.6%) were hip and 254 (47.4%) knee replacements; mean age was 71 years and 53.9% were female. ASA distribution was I 6.7%, II 66.6%, III 25.9% and IV 0.7%. Intensive care admission was rare (3/536, 0.6%), and none of the 139 ASA III patients required escalation. Nine patients (1.7%) required non-orthopaedic postoperative medical review; seven were ASA III and two ASA IV, all aged at least 74 years. ASA III status was associated with higher odds of medical review versus ASA I-II (OR 4.7, 95% CI 1.5-14.7, p = 0.007). Transfusion was infrequent (6/536, 1.1%). Median length of stay was 1.4 days (mean 2.6); only 13 patients (2.4%) stayed longer than 10 days, predominantly ASA III-IV.
Conclusions: ASA III patients comprised one quarter of this arthroplasty cohort and had very low rates of serious perioperative complications, with no postoperative intensive care use and low transfusion rates despite higher rates of non-orthopaedic medical review in older patients. With appropriate optimisation and clear escalation pathways, ASA III status alone should not be an exclusion criterion for stand-alone elective hubs without on-site ITU.
