Elevated surface chlorophyll associated with natural oil seeps in the Gulf of Mexico

Natural hydrocarbon seeps occur on the sea floor along continental margins, and account for up to 47% of the oil released into the oceans. Hydrocarbon seeps are known to support local benthic productivity, but little is known about their impact on photosynthetic organisms in the overlying water column. Here we present observations with high temporal and spatial resolution of chlorophyll concentrations in the northern Gulf of Mexico using in situ and shipboard flow-through fluorescence measurements from May to July 2012, as well as an analysis of ocean-colour satellite images from 1997 to 2007. All three methods reveal elevated chlorophyll concentrations in waters influenced by natural hydrocarbon seeps. Temperature and nutrient profiles above seep sites suggest that nutrient-rich water upwells from depth, which may facilitate phytoplankton growth and thus support the higher chlorophyll concentrations observed. Because upwelling occurs at natural seep locations around the world, we conclude that offshore hydrocarbon seeps, and perhaps other types of deep ocean vents and seeps at depths exceeding 1,000 m, may influence biogeochemistry and productivity of the overlying water column

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

2013 WSES guidelines for management of intra-abdominal infections

Peer reviewe

Necrotising soft tissue infection in western Sydney: An 8‐year experience

Background: This study aimed to assess the risk factors, management, imaging validity, Laboratory Risk Indicator for Necrotising infection (LRINEC) score and outcomes of necrotising soft tissue infection (NSTI) at a western Sydney tertiary hospital. Methods: A retrospective study was conducted of all patients with NSTI from 2012 to 2019 at our institution. Patient characteristics, imaging, microbiology and site, LRINEC score, surgical management and outcomes/disposition were collected. Results: Thirty-six patients met the inclusion criteria with mean age of 52 years and body mass index of 38.1; 55.6% were male, 48% of Polynesian descent and 55.6% were diabetic. The most frequent sites of NSTI were perineal (30.6%), lower limb (30.6%), perianal (19.3%) and trunk (11.1%). A total of 64% of patients underwent computed tomography radiological imaging with diagnostic accuracy of 50%. The mean LRINEC score was 7 (1–20). A total of 52.8% were transferred from another facility or non-surgical teams which delayed surgical review by 11.4 h (P < 0.03) and operating time by 12.4 h (P < 0.04) compared with direct emergency department referrals to the on-call surgical team. There was no statistical difference in outcomes in both groups. The overall average time to surgical debridement was 16.2 h (standard deviation 19.6, range 3.4–105.1). The mean hospital length of stay was 20.9 days; 44.4% of patients were transferred for rehabilitation or plastic reconstruction with a single mortality from multi-organ failure. Conclusion: The optimal management of NSTI requires a high index of suspicion and LRINEC score is a useful adjunct in aiding a clinician's decision. Early surgical debridement within 24 h of diagnosis and a multidisciplinary approach is associated with a lower mortality rate