Journal article

Rationale and Design of the Balanced Anesthesia Study: A Prospective Randomized Clinical Trial of Two Levels of Anesthetic Depth on Patient Outcome After Major Surgery

Timothy G Short, Kate Leslie, Matthew TV Chan, Douglas Campbell, Christopher Frampton, Paul Myles



BACKGROUND: An association between relatively deep anesthesia, as guided by the bispectral index (BIS), and increased postoperative mortality has been demonstrated in 6 of 8 published observational studies, but association does not necessarily mean causality. Small clinical trials of anesthetic depth have demonstrated increased delirium and postoperative cognitive dysfunction in patients who were relatively deeply anesthetized, but have been inadequately powered to study mortality. A large-scale randomized study is required to determine whether causality exists. METHODS: The primary hypothesis of our study is that "light" anesthesia, defined as a BIS target of 50, will reduce all-cause morta..

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University of Melbourne Researchers


Awarded by New Zealand Health Research Council, Auckland, New Zealand

Awarded by Australian National Health and Medical Research Council, Australia

Awarded by Research Grants Council, Hong Kong Special Administrative Region, China

Funding Acknowledgements

This work is funded by the New Zealand Health Research Council (12-308-Short), Auckland, New Zealand; the Australian National Health and Medical Research Council (APP1042727), Australia; and the Research Grants Council (general research fund 461513), Hong Kong Special Administrative Region, China.