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

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

Background Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications. Methods We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC). Findings In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683–0·717]). Interpretation In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required. Funding British Journal of Surgery Society

Common bile duct stones: an unusual case of diarrhoea through a mucous fistula

We present a very unusual case of diarrhoea in a 77-year-old man. He had a previously complicated surgical history, with a loop ileostomy and a colonic mucous fistula. He developed a sudden onset of diarrhoea from his mucous fistula. A contrast enema suggested a cholecystocolonic fistula and subsequent computed tomography demonstrated a common bile duct stone caused a degree of obstruction. The patient was treated successfully by endoscopic retrograde cholangiopancreatography and stone extraction. This case demonstrated the role that contrast enema may still play in unusual cases of diarrhoea. </jats:p

Gastric Volvulus and Splenic Hematoma in a Paraoesophageal Hernia

A 70 year old gentleman presented with features of gastric outlet obstruction. He had recently been investigated for upper GI symptoms and a barium meal had revealed a large paraoesophageal hernia. He had positive gastric splash. Endoscopy confirmed the presence of a hiatus hernia with associated gastric volvulus. He underwent exploratory laparotomy and was found to have a large paraoesophageal hernial sac containing most of the stomach, part of the omentum and the spleen. There was organoaxial volvulus of the stomach and a large subcapsular splenic haematoma. Splenectomy with repair of the hernia and gastropexy was performed after reducing the contents and excising the sac. He recovered well and was discharged on the eleventh postoperative day</jats:p

Delayed diagnosis of blunt traumatic diaphragmatic hernia

A 52-year-old man presented with a 3-day history of left shoulder-tip pain and shortness of breath, in the background of abdominal pain for 3 weeks. The patient had been admitted 4 months previously following a fall onto his left posterior chest wall, when he sustained a left-sided pneumothorax and fractures of the left 6th, 7th and 8th ribs posteriorly. At that time a computed tomography scan showed a left-sided pneumothorax with associated basal atelectasis and consolidation. On this, the second admission, initial observations were stable, apart from a mild tachypnoea. Abdominal examination was normal, but respiratory auscultation revealed bowel sounds in the left hemithorax. The chest radiograph showed a new left-sided pneumothorax and large bowel in the left chest (Figure 1). Abdominal radiography confirmed this, with some mildly dilated loops of bowel. A computed tomography scan demonstrated a left diaphragmatic rupture with associated intra-thoracic incarcerated large bowel, a left hydropneumothorax and mediastinal shift to the right (Figures 2 and 3). Subsequently, the patient underwent a transverse colectomy with colostomy formation, along with diaphragmatic repair through a left thoraco-abdominal approach. Gastrointestinal continuity was later restored electively. </jats:p