Objectives:
Withdrawal of life-sustaining therapy (WLST) is the most common cause of death following cardiac arrest (CA). A well-described “self-fulfilling prophecy” exists, in which a poor exam often prompts WLST. The prognostic value of the neurological exam at various time points, in the absence of WLST, remains unknown.
Methods:
All patients (N=291) treated at Columbia University with therapeutic hypothermia (TH) following CA between May 2007 and February 2015 were identified. Neurological exams were documented at admission, 72 hours, five days and seven days after arrest. Glasgow coma motor scores (GCS-motor) no better than extensor posturing, bilaterally absent pupillary light response and bilaterally absent corneal reflexes were considered poor exams. Patients were excluded if the cause of death was WLST (n=125) or they died despite full support prior to 7 days (n=70). A cerebral performance score (CPC) at hospital discharge of 3-5 was considered a bad outcome. False positive rates (FPRs) in percentages were calculated.
Results:
A total of 96 patients were analyzed (average age 59±17 years, 40% female, 91% with pre-hospitalization CPC 1-2, bystander CPR in 69%, initial rhythm of VT/FT in 41%, mean ROSC 19±15 minutes). Sixty-one percent of patients had a poor outcome. GCS-motor was associated with a poor outcome, with FPRs of 36.3% (21-63.6), 29.4% (15.7-47.7), 11.8% (3.8-28.4) and 10.8% (3.5-26.4) at admission, 72 hours, five days and seven days respectively. Bilaterally absent corneal reflexes had FPRs of 29.2% (13.4-51.3), 26.3% (10.1-51.4), 5.3% (0.3-28.1) and 0% (0-18.5). Bilaterally absent pupillary response had the lowest FPRs at 8.3% (2.2-23.6), 0% (0-13.3), 0% (0-14.1), and 0% (0-13.7).
Conclusion:
A poor neurological exam remains a significant predictor of poor outcome following cardiac arrest. In the setting of TH, the pupillary exam reaches 100% specificity at 72 hours, while the GCS-motor and corneal reflex have unacceptably high rates of good outcomes despite poor exams. They become more specific over time, suggesting that patients may benefit from delaying prognostication until at least five days after arrest.
Prognostic value of continuous EEG monitoring during therapeutic hypothermia after cardiac arrest
