BIS values during resuscitation: the role of the suppression ratio (case report)

We report a case during which it was simultaneously recorded usual Bispectral Index (BIS) values and elevated suppression ratio (SR) during resuscitation maneuvers. A 52-year-old woman, scheduled for a suspension laryngoscopy, required cardio-pulmonary resuscitation due to an anaphylactic shock secondary to the administration of succinylcholine. Post-crisis analysis of the BIS trace showed both BIS numbers consistent with an adequate level hypnosis and an increase in SR. Simultaneous hypnotic BIS values and an elevated SR is striking as SR quantifies electroenceph- alographic suppression. Clinicians must remember that SR is one of the parameters incorporated into BIS and must take SR into account even when the BIS is within the target range.