Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

The LEGS Score: A Proposed Grading System to Direct Treatment of Chronic Lower Extremity Ischemia

OBJECTIVE: To prospectively compare the Lower Extremity Grading System (LEGS)-derived “recommended treatment” to the actual treatment performed and to analyze LEGS intergrader scoring consistency by comparing blinded scoring results between physician graders. SUMMARY BACKGROUND DATA: Due to technical advances and the increased medical complexity of the aging population, the most appropriate treatment for chronic lower extremity ischemia—open surgery versus endovascular—is again in flux. In an attempt to standardize management, the LEGS score, based on the best available outcomes data, was devised by the physicians of an established vascular service. METHODS: From March to June 2002, all chronically ischemic lower extremities that met standard indications for revascularization were prospectively enrolled and independently graded with the LEGS score by an “endovascular surgeon” and an “open surgeon” for comparative analysis. The results were then blindly evaluated to determine whether the LEGS-derived “recommended treatment” agreed with the actual treatment rendered and to assess for intergrader consistency. Agreement was assessed using kappa statistical analysis. RESULTS: Of the 137 presenting limbs (mean patient age 66.4 yo; 43% claudication, 57% limb-threatening ischemia), 107 were treated (65% endovascular, 30% open surgery, 5% amputation), 16 were pending treatment, and 14 were not treated because of patient refusal (n = 13) or death (n = 1). The LEGS score predicted the actual or offered clinical treatment in 90% of cases. The LEGS score comparison between physician graders resulted in identical “recommended treatment” in 116 of 128 cases for a 90.6% agreement. CONCLUSIONS: A reproducible scoring system to guide the treatment of patients with chronic lower extremity ischemia is possible. While systems like the LEGS score may have potential clinical application, their use as a treatment standardization tool for future prospective outcomes comparisons between open and endovascular surgery will be essential