POSSUM and p-POSSUM overestimate morbidity and mortality in laparoscopic bariatric surgery.

BACKGROUND: Despite their wide use in surgical audit, the application of the Physiologic and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM) and the Portsmouth predictor of mortality (p-POSSUM) in bariatric surgery has been limited. The aim of this study was to evaluate the usefulness of POSSUM and p-POSSUM in bariatric comparative audit. METHODS: Data were retrospectively collected on consecutive patients who underwent laparoscopic gastric by-pass (LRYGB) and sleeve gastrectomy (SG) at a teaching institute. POSSUM and p-POSSUM equations were applied. The observed to expected ratios for morbidity and mortality were calculated. A Student's t test was performed to assess if a relationship could be found between the observed and the predicted outcomes. RESULTS: Between 2008 and 2013, 504 patients (370 female) with a mean (range) age of 46 (17-69) years underwent LRYGB (n = 383) and SG (n = 121). The operative morbidity was 10.9% and mortality was .2%. POSSUM overpredicted morbidity (30.56%), and no relationship between morbidity risk and the development of complications was found (P = .152). There was a grouping of patients in the low-risk mortality groups for both POSSUM and p-POSSUM. Both equations overpredicted mortality (5.95% and 1.62%, respectively). CONCLUSION: Both POSSUM and p-POSSUM equations overpredicted morbidity and mortality in this only study in the literature of modern bariatric practice that employed a large representative patient sample receiving the commonest procedures. A multicenter study is needed to address the low incidence of events and enable modification of those equations for use in bariatric surgical audit.

Randomised, double blind, placebo controlled trial of intravenous antioxidant (n-acetylcysteine, selenium, vitamin C) therapy in severe acute pancreatitis.

BACKGROUND: Based on equivocal clinical data, intravenous antioxidant therapy has been used for the treatment of severe acute pancreatitis. To date there is no randomised comparison of this therapy in severe acute pancreatitis. METHODS: We conducted a randomised, double blind, placebo controlled trial of intravenous antioxidant (n-acetylcysteine, selenium, vitamin C) therapy in patients with predicted severe acute pancreatitis. Forty-three patients were enrolled from three hospitals in the Manchester (UK) area over the period June 2001 to November 2004. Randomisation stratified for APACHE-II score and hospital site, and delivered groups that were similar at baseline. RESULTS: Relative serum levels of antioxidants rose while markers of oxidative stress fell in the active treatment group during the course of the trial. However, at 7 days, there was no statistically significant difference in the primary end point, organ dysfunction (antioxidant vs placebo: 32% vs 17%, p = 0.33) or any secondary end point of organ dysfunction or patient outcome. CONCLUSIONS: This study provides no evidence to justify continued use of n-acetylcysteine, selenium, vitamin C based antioxidant therapy in severe acute pancreatitis. In the context of any future trial design, careful consideration must be given to the risks raised by the greater trend towards adverse outcome in patients in the treatment arm of this study.