Background This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. Methods This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score‐matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score‐matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery. Results A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score‐matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498). Conclusion There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast‐induced nephropathy should not be used as a reason to avoid contrast‐enhanced CT.

The peri-operative use of angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers is thought to be associated with an increased risk of postoperative acute kidney injury. To reduce this risk, these agents are commonly withheld during the peri-operative period. This study aimed to investigate if withholding angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers peri-operatively reduces the risk of acute kidney injury following major non-cardiac surgery. Patients undergoing elective major surgery on the gastrointestinal tract and/or the liver were eligible for inclusion in this prospective study. The primary outcome was the development of acute kidney injury within seven days of operation. Adjusted multi-level models were used to account for centre-level effects and propensity score matching was used to reduce the effects of selection bias between treatment groups. A total of 949 patients were included from 160 centres across the UK and Republic of Ireland. From this population, 573 (60.4%) patients had their angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers withheld during the peri-operative period. One hundred and seventy-five (18.4%) patients developed acute kidney injury; there was no difference in the incidence of acute kidney injury between patients who had their angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers continued or withheld (107 (18.7%) vs. 68 (18.1%), respectively; p = 0.914). Following propensity matching, withholding angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers did not demonstrate a protective effect against the development of postoperative acute kidney injury (OR (95%CI) 0.89 (0.58-1.34); p = 0.567).

Purpose Transurethral procedures, including transurethral resection of the prostate (TURP) and laser prostatectomy, are often linked to emergency room (ER) visits for postoperative bleeding. Although some studies have been conducted, the risk factors associated with these ER visits are not completely understood. This retrospective cohort study identified potential risk factors associated with ER visits for postoperative bleeding. Patients and Methods Preoperative assessment data and operational and postoperational parameters recorded at Chang Gung Memorial Hospital, Taiwan between December 2015 and January 2017 for patients who underwent elective transurethral procedures were analyzed to identify potential risk factors. The primary endpoint was ER visits for gross hematuria within three months following operation, and the secondary endpoint was ER visits for blood clot-induced urinary retention (clot retention) within three months following operation. Results A total of 665 patients who underwent elective transurethral procedures were enrolled. The transurethral procedures included monopolar transurethral resection of the prostate (M-TURP), bipolar TURP (B-TURP), greenlight photoselective vaporization of the prostate (PVP), thulium laser enucleation of the prostate (ThuLEP) and thulium laser transurethral vaporesection of the prostate (ThuVARP). Regarding ER visits for clot retention within three months, multivariable logistic regression revealed significantly lower rates of clot retention in patients who received B-TURP than in those who underwent ThuVARP (AOR, 0.18; 95% confidence interval [CI], 0.04–0.82, p = 0.027). Moreover, significantly higher clot retention was observed in patients who underwent two or more rounds of manual irrigation (AOR, 9.51; 95% CI, 1.66–54.43, p = 0.011). Conclusion Multiple manual irrigations shortly after operation can be considered a novel predictor of postoperative clot retention-related ER visits. Among the transurethral procedures, ThuVARP was associated with a higher risk of clot retention-related ER visits than was B-TURP.

Background Postoperative acute kidney injury (AKI) is a common complication of major gastrointestinal surgery with an impact on short- and long-term survival. No validated system for risk stratification exists for this patient group. This study aimed to validate externally a prognostic model for AKI after major gastrointestinal surgery in two multicentre cohort studies. Methods The Outcomes After Kidney injury in Surgery (OAKS) prognostic model was developed to predict risk of AKI in the 7 days after surgery using six routine datapoints (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). Validation was performed within two independent cohorts: a prospective multicentre, international study (‘IMAGINE’) of patients undergoing elective colorectal surgery (2018); and a retrospective regional cohort study (‘Tayside’) in major abdominal surgery (2011–2015). Multivariable logistic regression was used to predict risk of AKI, with multiple imputation used to account for data missing at random. Prognostic accuracy was assessed for patients at high risk (greater than 20 per cent) of postoperative AKI. Results In the validation cohorts, 12.9 per cent of patients (661 of 5106) in IMAGINE and 14.7 per cent (106 of 719 patients) in Tayside developed 7-day postoperative AKI. Using the OAKS model, 558 patients (9.6 per cent) were classified as high risk. Less than 10 per cent of patients classified as low-risk developed AKI in either cohort (negative predictive value greater than 0.9). Upon external validation, the OAKS model retained an area under the receiver operating characteristic (AUC) curve of range 0.655–0.681 (Tayside 95 per cent c.i. 0.596 to 0.714; IMAGINE 95 per cent c.i. 0.659 to 0.703), sensitivity values range 0.323–0.352 (IMAGINE 95 per cent c.i. 0.281 to 0.368; Tayside 95 per cent c.i. 0.253 to 0.461), and specificity range 0.881–0.890 (Tayside 95 per cent c.i. 0.853 to 0.905; IMAGINE 95 per cent c.i. 0.881 to 0.899). Conclusion The OAKS prognostic model can identify patients who are not at high risk of postoperative AKI after gastrointestinal surgery with high specificity. Presented to Association of Surgeons in Training (ASiT) International Conference 2018 (Edinburgh, UK), European Society of Coloproctology (ESCP) International Conference 2018 (Nice, France), SARS (Society of Academic and Research Surgery) 2020 (Virtual, UK).

Background: The purpose of this study is to assess the roles of pediatric surgeons and adult trauma surgeons in the management of pediatric torso trauma patients in a Level I adult trauma center. Methods: From 2015 to 2019, pediatric torso trauma patients (age < 18 years) were studied. A comparison between patients who did and did not undergo surgery was performed. Older children (age: 10–18 years) were compared with young adults (age: 18–35 years) selected with the same criteria using propensity score matching (PSM) and inverse probability of treatment weighting (IPTW). Results: A total of 226 patients were included in the study. Patients who underwent surgery for torso trauma (N = 61) were significantly older than patients who did not undergo surgery (N = 165) (13.1 vs. 10.4 years, p = 0.019). Both PSM and IPTW showed that the older children and young adult groups had similar proportions of patients requiring surgery (32.6% vs. 32.6%, standard difference (SD) = 0.000), proportions of patients who required torso angioembolization (8.7% vs. 9.8%, SD = 0.072), length of hospital stay (LOS) (8.1 vs. 8.0 days, SD = 0.026), and intensive care unit admission LOS (2.6 vs. 2.7 days, SD = 0.033). However, 7.1% of older children received critical care from pediatric surgeons. Additionally, 31.9% of younger children were cared for by pediatric surgeons/pediatricians. Conclusions: Adult trauma surgeons can feasibly perform surgeries for older children with torso trauma in collaboration with pediatric surgeons who provide critical care.