EComment. Gastrointestinal complications in cardiac surgery

Abstract

We read with interest the best evidence topic article by Shin and Abah regarding routine stress ulcer prophylaxis in cardiac surgery [1]. We agree with their recommendation of routine acid suppression therapy for the prevention of gastrointestinal (GI) complications in patients undergoing cardiac surgery. Major GI complications following cardiac surgery consist mainly of upper GI bleeding and GI ischaemia followed by peptic ulcer disease, diverticulitis, pancreatitis and cholecystitis [2, 3, 4]. We have audited our practice with regards to major GI complications in patients undergoing cardiac surgery [2]. We found out that after routine introduction of acid suppression therapy, there was a significant reduction in GI complications related to upper GI bleeding. Therefore, there was no single practice in various cardiothoracic units in the United Kingdom [2]. In their retrospective study of 51 patients with GI complications (in total of 4819 patients), Filsulfi et al. listed the following as independent predictive factors of GI complications in cardiac surgery: age, myocardial infarction, congestive heart failure, haemodynamic instability, cardiopulmonary bypass time (over 120 min), peripheral vascular disease, and renal and hepatic failure [3]. The overall hospital mortality among patients with GI complications was higher and the long-term survival was significantly decreased in these patients compared with the control group [3]. In addition, Mangi et al. performed a retrospective analysis of 46 patients (out of 8709 patients) with GI complications and found the following to be preoperative predictor factors: prior cerebrovascular accident, chronic obstructive pulmonary disease, type II heparin-induced thrombocytopenia, atrial fibrillation, prior myocardial infarction, renal insufficiency, hypertension, and need for intra-aortic balloon counterpulsation [4]. Univariate predictors of increased mortality rate in patients with GI complications included New York Heart Association class III and IV, smoking, direct bilirubin over 2.4 mg/dl, pH less than 7.30, syncope at time of presentation, chronic obstructive pulmonary disease, aspartate transaminase over 600 mg/dl and the need for two or more pressors [4]. The National Institute of Clinical Excellence has recommended the treatment with acid suppression therapy (H2-receptor antagonists or proton pump inhibitors) in all acutely ill patients (admitted to intensive care or high dependency units) for primary prevention of upper GI bleeding. Therefore, depending on the patient, the oral form of acid suppression therapy is preferable [5]. The need of acid suppression therapy should be reviewed after the discharge of the patient from the intensive care or high dependency units on an individual basis and during their recovery process [5]. Acid suppression therapy can reduce the risk of acute upper GI bleeding and blood transfusion requirements. However, it does not significantly affect the mortality rate. The adverse events of ventilation-associated pneumonia and of Clostridium difficile-associated diarrhoea do not appear to be increased significantly after the introduction of acid suppression therapy [5]. In conclusion, GI complications in patients undergoing cardiac surgery remain rare but devastating. The early identification of predictive factors and the application of all the preventive measures are of paramount importance for the better outcome of these patients.