Characteristics, incidence, and outcomes of gastrointestinal complications post cardiac surgery in a quaternary referral centre: A retrospective study.

Background: Gastrointestinal (GI) complications after cardiac surgery are associated with high morbidity and mortality. Early identification and treatment of GI complications could improve patient outcomes.

Objectives: The objective of this study was to ascertain the incidence, risk factors, and clinical outcomes of GI complications following cardiac surgery.

Methods: A retrospective single-centre cohort study of adult patients undergoing cardiac surgery in an Australian quaternary cardiothoracic surgical referral centre was conducted from November 2012 to March 2020. Preoperative, intraoperative, and postoperative characteristics were compared between patients who did and did not develop GI complications. Data are presented as n (%). Between-group comparisons were analysed using Chi-square and Fisher's exact tests (where n < 6) for categorical variables and Wilcoxon rank-sum test for continuous variables.

Results: Of the 4417 patients who underwent cardiac surgery, 95 (2.2%) patients developed a total of 100 GI complications, with the most common being paralytic ileus (n = 22/100, 22%). Baseline characteristics and preoperative factors associated with GI complications included an age of >70 years (GI complication vs no GI complication: 55.8% vs 37.6%; p = 0.000), preexisting diabetes (49.5% vs 34.5%; p = 0.002), and a creatinine level >200 mcg/ml (11.6% vs 3.7%; p = 0.000). Intra-operative factors included a cardiopulmonary bypass time >120 min (28.4% vs 15.5%; p < 0.01). Postoperatively, developing a GI complication was associated with return to theatre (36.8% vs 13.9%; p < 0.01) and new stroke, pneumonia, and acute kidney injury (all p < 0.01). Patients with a GI complication had a higher intensive care unit and hospital mortality (7.4% vs 1.1%, and 13.6% vs 1.4%, respectively), and a longer intensive care unit and hospital stay (5.5 vs 2.3 days, and 24.0 vs 10.3 days).

Conclusions: Multiple risk factors associated with GI complications in cardiac surgery patients were identified. These provide potential targets to support the early detection and management of GI complications to reduce morbidity and mortality in these patients.