Abstract P204: Bispectral Index Monitoring for Prognostication After Cardiac Arrest Resuscitation and Therapeutic Hypothermia
Background: Prognostication of neurologic outcomes after cardiac arrest (CA) with the use of Therapeutic Hypothermia (TH) remains difficult, as current methods of assessment are inadequate. Initial reports have suggested that Bispectral Index (BIS) monitoring, used to assess consciousness during anesthesia, may have utility in this setting although published data remain sparse.
Objectives: We hypothesized that BIS values during the initial 48 hours of post-CA care correlates with survival outcomes and neurologic function at hospital discharge.
Methods: We performed a prospective cohort study of all post-CA patients who received TH at our tertiary care hospital from June 2007 to April 2009. BIS values were captured at 0, 12, 24 and 48 hrs post-arrest. Means were compared via student t-tests.
Results: Of our cohort, 38 patients achieved ROSC and received TH. Mean age was 55±14, 11/38 (29%) were female, and 17/38 (45%) survived to discharge. Comparing survivors vs non-survivors (Figure⇓), mean BIS values were significantly different at 24 hr (p<0.001) and 48 hr (p=0.013) - although some patients at 48 hrs were no longer paralyzed. Four patients had a BIS value of 0 during at least one timepoint; none survived to discharge despite only one having care withdrawn before clinical brain death. Survivors with cerebral performance category (CPC) scores 3–5 (i.e. worse outcomes) had significantly lower BIS values averaged over all timepoints (CPC 1–2: 51±7 vs CPC 3–5: 40±9, p=0.014).
Conclusions: Higher mean BIS values during and after TH are significantly associated with favorable outcomes, although there was no clearly identifiable “cut point” to determine survival.