In patients coming to theatre with an intra aortic balloon pump, is it better to turn it off or keep it on while on bypass?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'In patients coming to theatre with an intra aortic balloon pump (IABP), is it better to turn it off or keep it on while on bypass?' Altogether 46 papers were found using the reported search, of which 11 represented the best evidence to answer the clinical question. Nine of them were randomised controlled trials (RCTs). The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The different RCTs were performed looking at various effects of IABP induced pulsatility during cardiopulmonary bypass (CPB) and cardioplegic arrest. These studies showed that IABP induced pulsatile perfusion results in improved perfusion to vital organs, better lung function in chronic obstructive pulmonary disease patients, ameliorates the coagulative system and lowers endothelial activation. Despite these facts a survey in the UK and Ireland showed that 80.5% of cardiac surgeons stop IABP on commencing CPB. We conclude that in patients who already have IABP in-situ whilst going on CPB there is enough evidence in the literature to suggest that it should be turned on to internal trigger mode. Although several randomised control trials in this field have conveyed considerable benefit in terms of biochemical markers measured, none of them have resulted in better clinical outcomes in terms of reduction in major morbidity or mortality. This may be largely due to the small sample size in most of these studies. Seven out of 11 papers were published by same group of authors.