Objectives: To determine the longitudinal changes in functional outcome and compare ordinal outcome scale assessments in comatose cardiac arrest survivors.
Design: Prospective observational study of comatose cardiac arrest survivors. Subjects who survived to 1 month were included.
Setting: Academic medical center ICU.
Patients: Ninety-eight consecutive patients who remained comatose after resuscitation from cardiac arrest; 45 patients survived to 1 month.
Interventions: None.
Measurements and main results: Patients' functional neurologic outcomes were assessed by phone call or in-person clinic visit at 1, 3, 6, and 12 months postcardiac arrest using the modified Rankin Scale, Glasgow Outcome Scale, and Barthel Index. A "good" outcome was defined as modified Rankin Scale 0-3, Barthel Index 70-100, and Glasgow Outcome Scale 4-5. Changes in dichotomized outcomes and shifts on each outcome scale were analyzed. The mean age of survivors was 51 ± 19 years and 18 (40%) were women. Five (19%) out of 26 patients with data available at all timepoints improved to good modified Rankin Scale outcome and none worsened to poor outcome between postarrest months 1 and 6 (p = 0.06). Thirteen patients (50%) improved on the modified Rankin Scale by 1-3 points and four (15%) worsened by 1-2 points between months 1 and 6 (overall improvement by 0.5 points; 95% CI, 0-1; p = 0.04). From postarrest months 6 to 12, there was no change in the number of patients with good versus poor outcomes. The modified Rankin Scale and Barthel Index were more sensitive to detecting changes in outcome than the Glasgow Outcome Scale.
Conclusions: In initially comatose cardiac arrest survivors, improvements in functional status occur over the first 6 months after the event. There was no significant change in outcome between postarrest months 6 and 12. The modified Rankin Scale is a sensitive outcome scale in this population.