Abstract TP87: Early Quantitative Somatosensory Evoked Potentials Markers after Cardiac Arrest

Abstract

Background and Purpose: The high incidence of poor functional outcome following cardiac arrest (CA) signifies the importance of prognostic tools to track recovery. This study evaluates the prognostic value of quantitative somatosensory evoked potentials (SSEPs) under targeted temperature management (TTM). We hypothesize that the integrity of thalamocortical pathways involved in SSEP may be represented by amplitude and latency, which may provide an indication of outcome. Methods: Twenty-one Wistar rats underwent 7min asphyxia-CA followed by immediate TTM (n=7/group): hypothermia (33±1 ° C), normothermia (37±0.5 ° C), hyperthermia (39±0.5 ° C). Fourteen additional rats underwent sham surgery followed by TTM. SSEPs were recorded before CA and 30min-4hr post-resuscitation. Functional outcome was evaluated by 72hr Neurologic Deficit Scale (NDS) score. N7 and N10 amplitude and latency during early recovery were normalized to baseline values. Results: Sham animals had significantly higher N10 amplitudes (p<0.05) and N7 and N10 latencies (p<0.01) under hypothermia, and shorter N7 and N10 latencies (p<0.05) under hyperthermia, compared to normothermia. N7 and N10 latency and N10 amplitude were significantly higher in hypothermic CA animals than normothermic and hyperthermic CA animals (p<0.01) and in good (72hr NDS≥60) compared to poor (72hr NDS<60) outcome animals (p<0.01). N10 amplitude had 50% sensitivity for good outcome at 30min post-resuscitation with 100% specificity. Conclusions: SSEP N10 amplitude during early recovery from CA with TTM is associated with functional outcome and predicts good outcome in a rodent model.