Depth of anesthesia causality dilemmas: the next generation

Relation between bispectral index measurements of anesthetic depth and postoperative mortality: a meta-analysis of observational studies

“…6 Subsequent studies, however, yielded conflicting results. 7 At least two narrative reviews summarized the literature on this topic, each of which reported a clinically important correlation between depth of anesthesia and mortality. 8,9 However, these conclusions were based only on qualitative analyses, wherein authors provided individual interpretations of potentially disparate conclusions rather than quantifying a measured effect size.…”