Impact of the Acute Surgical Unit on a Local and Global Scale

Abstract

Introduction Traditionally, general surgical departments allocated their staff to elective operative and outpatient commitments, with emergency general surgical (EGS) patients managed ad-hoc. An acute surgical unit (ASU) model was pioneered in 1996 and spread globally. However, uptake remains slow, in part due to clinical equipoise. This thesis aims to address key gaps in the literature, to support hospitals considering establishing an ASU and EGS policymakers. Methods Locally, three retrospective studies were performed at the Lyell McEwin Health Service. For patients with appendicitis or cholecystitis, these compared cohorts ≤2.5 years pre/post ASU introduction. Primary outcomes were length of stay, time to theatre, after-hours operating rates, rates of cholecystectomy on index admission and rates of appropriate communication and management of incidental pathology (appendicitis patients only). A fourth study prospectively assessed patient reported outcomes within the Royal Adelaide Hospital ASU. Primary outcomes were factors associated with patient satisfaction on multivariate analysis. Nationally, two studies reported the results of a cross-sectional assessment of the general surgery departments in all medium-large sized Australian public hospitals. Primary outcomes were the spectrum of EGS models in use, staff satisfaction and operative exposure. Globally, two systematic reviews were performed. The first identified ASU-type dedicated models of care for emergency patients in urology. The primary outcome was the spectrum of models. The second collated for meta-analysis general surgery studies comparing the Traditional and ASU models. Primary outcomes were length of stay, cost and rates of after-hours operating and complications. Results Locally, single centre retrospective studies of 319–1,214 patients found that establishing an ASU was associated with reduced time to theatre and rates of after-hours operating, and superior rates of cholecystectomy on index admission. Length of stay was reduced for patients with cholecystitis but not appendicitis. For presumed-appendicitis patients with incidental pathology, rates of communication or appropriate management were unchanged. Nationally, the cross-sectional study enrolled 119/120 eligible hospitals. Sixty-four (54%) hospitals reported using an ASU or hybrid EGS model. Compared with the Traditional structure, hybrid or ASU models were associated with greater surgeon and registrar satisfaction. Registrar-perceived operating exposure was unaffected by EGS model. Globally, the first systematic review identified seven centres implementing a variety of dedicated models for emergency urological patients. The second review enrolled 77 publications representing 150,981 unique EGS patients from thirteen nations. Compared with the Traditional model, ASU introduction was associated with reductions in length of stay and rates of after-hours operating and complications. Financial assessments found the ASU to deliver equivalence or cost savings. Conclusion Compared with the Traditional structure, the ASU model delivers superior outcomes. The ASU model should be promoted in health policy to benefit patients, staff and health budgets. Further improvements may involve ASU wards as centres of education and excellence, linked contractual obligation and increased funding for general surgeons to deliver EGS care and greater inter-hospital coordination. Future research includes cost analyses, quality improvement initiatives measured by patient reported outcomes and assessment of ASU model utility in other surgical specialties and in low-income countries.