BALANCED
Research type
Research Study
Full title
The influence of anaesthetic depth on patient outcome after major surgery (The BALANCED Anaesthesia Study)
IRAS ID
141623
Contact name
Gary Mills
Contact email
Sponsor organisation
Auckland District Health Board
Research summary
Recent observational studies have found an association between deep anaesthesia and increased postoperative mortality in elderly and infirm patients undergoing major surgery. It is unknown whether there is a causal relationship in this observation, which occurs at levels of anaesthetic depth that are within the normal range of
practice. We are performing a large randomised trial of ‘deep’ versus ‘light’ anaesthesia to definitively answer the question of whether anaesthetic depth alters perioperative outcome. Our primary hypothesis is that light general anaesthesia (bispectral index = 50) is associated with decreased all cause mortality compared with deep general anaesthesia (bispectral index = 35) one year after major surgery in elderly patients. 6,500 elderly patients undergoing major surgery will be randomised worldwide to an anaesthetic targeting either bispectral index = 35 or bispectral index = 50 for the deep and light groups respectively. The primary outcome variable will be all cause mortality at one year and secondary outcomes will be myocardial infarction, cardiac arrest, pulmonary embolism, stroke, sepsis, surgical site infection, intensive care unit stay, hospital stay, awareness, World Health Organisation disability assessment score, persistent postoperative pain and cancer recurrence. All patients and outcome assessors will be blind to group allocation and study endpoints will be adjudicated by an endpoint adjudication committee. A data monitoring committee has been established by the Health Research Committee in New Zealand. An interim analysis will be performed when 2000 patients have completed one year followup.REC name
Yorkshire & The Humber - Bradford Leeds Research Ethics Committee
REC reference
14/YH/0076
Date of REC Opinion
20 Jun 2014
REC opinion
Further Information Favourable Opinion