Determinants of gastrointestinal complications in cardiac surgery

Abstract

We designed this study to define determinants of gastrointestinal complications after cardiac surgery. From January 1992 through December 2000, 11,058 patients underwent cardiac surgery on cardiopulmonary bypass at our institution. Data were prospectively collected and univariate and multivariate analyses conducted. A total of 147 gastrointestinal complications occurred in 129 patients (129/11,058; 1.2%) including gastroesophagitis (18, 12.2%), upper gastrointestinal hemorrhage (42, 28.6%), perforated peptic ulcer (7, 4.7%), cholecystitis (10, 6.8%), pancreatitis (13, 8.8%), intestinal ischemia (17, 11.5%), colitis (18, 12.2%), diverticulitis (5, 3.4%), intestinal occlusion (2, 1.1%), lower gastrointestinal hemorrhage (1, 0.7%), and mixed gastrointestinal complications (14, 9.5%). Patients with gastrointestinal complications were significantly older and had significantly higher comorbidity (unstable angina, chronic renal failure, and peripheral vascular disease), morbidity (prolonged mechanical ventilation, intraaortic balloon pumping, bleeding, acute renal failure, stroke, and infection), and mortality rates (22.5% vs 4%, P < 0.0001). They also had longer cardiopulmonary bypass times and higher valvular surgery rates. Multivariate analysis identified 6 independent predictors for gastrointestinal complications: prolonged mechanical ventilation (odds ratio [OR], 5.5), postoperative renal failure (OR, 4.2), sepsis (OR, 3.6), valve surgery (OR, 3.2), preoperative chronic renal failure (OR, 2.7), and sternal infection (OR, 2.4). Factors such as mechanical ventilation, renal failure, and sepsis are the stronger predictors for GI complications, causing splanchnic hypoperfusion, hypomotility, and hypoxia. Furthermore, excessive anticoagulation after valve replacement may lead to GI hemorrhage. Valve surgery, often requiring anticoagulation, increases bleeding. Monitoring mechanical ventilation and hemodynamic parameters, adopting early extubation and mobilization measures, preventing infections, and strictly monitoring renal function and anticoagulation may prevent catastrophic abdominal complications.

Fig. 1 Mortality rate by gastrointestinal (GI) complication.