Impact of direct transfer to critical care on mortality for patients who undergo emergency colorectal cancer resection: a national population-based cohort study in England

Background It is recommended that patients receiving emergency surgery and with ‘high-risk' of morbidity and mortality should be transferred directly from theatre to critical care. Using a national, population-based cohort study, we estimated the effect of direct transfer to critical care on 90-day mortality after emergency colorectal cancer resection, and the variation amongst English NHS hospitals. Methods Patients who underwent emergency colorectal cancer resection between December 2016 and November 2019 according to Hospital Episodes Statistics, National Bowel Cancer Audit or National Emergency Laparotomy Audit were included. Patients were identified as having a direct transfer to critical care through linkage with the Intensive Care National Audit and Research Centre Case Mix Programme. Multivariable logistic regression and propensity score methods were used to measure the effect of direct transfer to critical care on 90-day mortality. Results In total, 10,441 patients underwent an emergency colorectal cancer resection. Unadjusted 90-day mortality was higher in the direct transfer to critical care cohort (10.9%) than in patients without direct transfer to critical care (3.7%) (odds ratio [OR]: 3.16, 95% confidence interval [CI]: 2.65–3.77). There was no evidence of an association after risk adjustment (adjusted OR: 1.16, 95% CI: 0.94–1.43) or after propensity score analysis (weighted OR: 0.94, 95% CI: 0.69–1.27). For patients at high risk with a predicted mortality ≥5%, the proportion of patients with a direct transfer to critical care varied widely amongst hospitals (interquartile range 68%–92%; median 83%). Conclusions Our findings suggest that apparent higher postoperative mortality in patients having direct transfer to critical care can be mostly explained by characteristics of patients, tumours, physiology and surgery. However, the extent to which direct transfer to critical care is used varies widely amongst hospitals. Further work to understand this variation has the potential to improve patient outcomes after emergency colorectal cancer resection.