NIRS - evidence- or eminence-based practice?

Green and Kunst support the routine use of cerebral near-infrared spectroscopy (NIRS) as part of a multi-modal approach to monitoring adult patients undergoing cardiac and non-cardiac surgery, and resuscitation 1, despite a cited previous systematic review 2 suggesting its abandonment because its use does not seem to improve outcome. Furthermore, the technology appears too imprecise to be able to derive any information other than relative (rather than absolute) changes in regional cerebral oxygen saturation. We think that Green and Kunst's support lacks evidential basis, therefore, beyond the use of NIRS in cardiac surgery, and risks ‘eminence-based’ implementation instead 3, 4, obfuscating the efficiency and safety afforded by evidence-based practice 5. Further evidence, using standardised outcomes 6, is needed before the benefits of routinely using cerebral NIRS can be properly supported