The association of brainstem and motor recovery with awakening after out-of-hospital cardiac arrest

BACKGROUND: Coma is common following resuscitation from cardiac arrest. Few data describe the trajectory of recovery the first days following resuscitation. The objective of this study is to describe the evolution in neurological examination during the first 5 days after resuscitation and test if subjects who go on to awaken have different patterns of early recovery. METHODS: Prospective study of adult subjects resuscitated from out-of-hospital cardiac arrest. We abstracted demographic information and trained clinicians completed daily neurologic examinations using the Glasgow Coma Scale (GCS) and Full Outline of UnResponsiveness brainstem (FOUR-B) and motor (FOUR-M) scores during daily sedation interruption. The change in scores between Day 1 and Day 5 was analyzed using the Kruskal-Wallis Test and logistic regression models. The relationship of FOUR-B, FOUR-M, and GCS with time to death was estimated by fitting cox proportional hazard models. RESULTS: FOUR-M and GCS did not differ over time (p = 0.10; p = 0.07). FOUR B increased over time (p < 0.01). Time to recovery of brainstem or motor function differed between those treated at 33 °C and 36 °C (p = 0.0023 and p = 0.0032, respectively). FOUR-B, FOUR-M, and GCS differed between survivors and non-survivors (p < 0.01). Time to recovery of brainstem and motor function differed between survivors and non-survivors. FOUR-M and FOUR-B differed between those with good outcome and poor outcome. CONCLUSIONS: The brainstem clinical examination improved during the first 5 days following resuscitation. Brainstem recovery was common in entire cohort and did not differentiate between survivors and non-survivors. Recovery of motor function, however, was associated with survival.