Background: Outpatient appendectomy for acute appendicitis is a feasible, yet not widely performed procedure, as there are no universally accepted criteria for patient selection. The aim of this study was to assess preoperative clinical factors associated with successful short-stay appendectomy (SSA) and establish a predictive score to help with patient selection.
Methods: All consecutive laparoscopic appendectomies performed in our institution between January 2013 and June 2015 were retrospectively analyzed. Several preoperative clinical and biological variables were compared between patients with SSA, defined as a postoperative stay <24 h, and those needing inpatient care. Logistic regression analysis was used to identify variables independently associated with SSA, and these variables were then used to create a predictive score.
Results: A total of 578 patients were included, 303 (53%) in the SSA group and 275 (48%) in the long-stay appendectomy (LSA) group. In multivariate analysis, male gender (OR 1.61, 95% CI 1.12-2.31, p = 0.010), ASA class I-II (OR 9.52, 95% CI 1.65-180.69, p = 0.037), absence of generalized guarding (OR 3.55, 95% CI 1.30-11.41, p = 0.019), C-reactive protein <100 mg/dl (OR 3.09, 95% CI 1.81-5.42, p < 0.001) and leukocyte count <20 g/l (OR 2.06, 95% CI 1.02-4.30, p = 0.046) were independently associated with SSA. These five parameters were used to construct a predictive score, whereby ≥17 (range 0-21) was defined as the optimal threshold to predict SSA with a high sensitivity (95.6%) and negative predictive value (82.2%).
Conclusions: A purely clinical predictive score based on five widely used preoperative parameters can be used to identify eligible patients for short-stay appendectomy.