Effect of pre-admission immunosuppressive therapy and regional transfer versus metropolitan hospital presentation on colectomy rates in acute severe ulcerative colitis

Abstract

Ulcerative colitis is a chronic idiopathic inflammatory disorder of the colon with a relapsing remitting course. It affects 40,000 Australian patients currently.1 During their disease course 1 in 5 of these patients develop a severe episode of colitis requiring hospital admission and a significant proportion of them 19-40 % require resection of the colon to remain healthy.2 The colectomy rate of acute severe ulcerative colitis (ASUC) continues to remain high despite significant advances in medical therapy over the last three decades. Risk stratification and optimal treatment strategy remain clinical challenges. It has been suggested by some authors that patients established on immunosuppressive therapy at the time of severe ulcerative colitis are a higher risk for colectomy than those not on treatment.3 Over half the patients admitted for this condition are on treatment at the time of admission but the outcomes of these patients have not been well studied. In addition many patients are transferred to large tertiary metropolitan hospitals from smaller regional hospitals which lack inflammatory bowel disease or gastroenterology specialty input. The initial management of these patients is therefore undertaken in these regional hospitals and the effect of this on colectomy rates not currently known.This thesis firstly aimed to identify whether being on immunosuppressive treatment at the time of admission with ASUC increases the risk of colectomy. Secondly this thesis aimed to compare the colectomy rates of ASUC patients presenting initially to regional with those presenting directly to a metropolitan tertiary hospital. We aimed to identify the driving factors for any inequality to allow development of strategies to improve the outcome of regional patients with this condition.Our findings show that immunosuppressive therapy prior to admission with ASUC does not significantly increase the colectomy rate. Predictors of colectomy confirmed were colonic dilation ≥ 5.5cm, transfer from a regional hospital, CRP level ≥ 45 mg/ml on day 3 of admission, first presentation of ulcerative colitis and bowel action frequency ≥ 8 on day 3 of treatment. Knowledge of these key parameters allows the clinician to select high risk patients for early and aggressive rescue therapy, stomal therapist and colorectal surgeon review.In regards to our second aim we found that regional transfer patients were three times as likely to undergo colectomy as patients presenting directly to our metropolitan hospital at 30 days post admission. The primary factor identified was poor response to intravenous steroids. Predictors of colectomy in regional transfer patients identified were bowel frequency ≥ 8 on day 3 and CRP ≥ 45 mg/L on day 3 of therapy.