title: Is it possible to predict the risk of ischaemic bowel after cardiac surgery?
abstract: A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'Is it possible to predict the risk of ischaemic bowel after cardiac surgery?' Altogether 80 papers were found as a result of the reported search, of which 7 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. This best evidence topic presents 68 214 cardiac surgical patients from seven major cardiothoracic centres dated from 1980 to 2011. The incidence and mortality rates of bowel ischaemia after cardiac surgery range from 0.07-0.5 and 59-64%, respectively. Advanced age and peripheral vascular disease are the common preoperative risk factors, which were reported by 3 papers each. The most common intraoperative risk factors were prolonged cross-clamp and cardiopulmonary bypass time, which were reported by 3 papers each. Five of 7 papers reported that the use of intra-aortic balloon pump was a significant risk factor. The use of inotropes, postoperative blood loss and postoperative renal failure were reported by 3 of 7 papers, each to be a significant risk factor for postoperative bowel ischaemia in cardiac surgery patients. We, therefore, conclude that these are probably the most significant and useful predictive risk factors for bowel ischaemia after cardiac surgery. Thus, careful intraoperative management to minimize cardiopulmonary bypass and cross-clamp time and optimal care of patients' postoperative haemodynamic status, particularly in elderly patients with severe atherosclerotic disease, are useful in preventing this rare but lethal postoperative complication. Besides that, a heightened clinical suspicion in patients with these risk factors may lead to prompt diagnosis of bowel ischaemia, allowing intervention to prevent mortality. The variability of the study design and risk factors studied in each paper impose limitation to summarize the predicting risk factors.
authors.affiliation: Department of Cardio-Thoracic Surgery, National Heart Centre Singapore, Singapore kokhooi84@hotmail.com.
authors.forename: Kok Hooi
authors.initials: KH
authors.lastname: Yap
authors.affiliation: Department of Cardio-Thoracic Surgery, National Heart Centre Singapore, Singapore.
authors.forename: Kim Chai
authors.initials: KC
authors.lastname: Chua
authors.affiliation: Department of Cardio-Thoracic Surgery, National Heart Centre Singapore, Singapore.
authors.forename: See Lim
authors.initials: SL
authors.lastname: Lim
authors.affiliation: Department of Cardio-Thoracic Surgery, National Heart Centre Singapore, Singapore.
authors.forename: Yoong Kong
authors.initials: YK
authors.lastname: Sin
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D019985:Benchmarking; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000401:mortality; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D002317:Cardiovascular Agents / Q000627:therapeutic use; D015897:Comorbidity; D003250:Constriction; D019317:Evidence-Based Medicine; D006439:Hemodynamics; D006801:Humans; D007423:Intra-Aortic Balloon Pumping / Q000009:adverse effects; D065666:Mesenteric Ischemia / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology / Q000517:prevention & control; D008875:Middle Aged; D016017:Odds Ratio; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D002317:Cardiovascular Agents
keywords: Cardiac surgery; Ischaemic bowels; Predict; Risk factors