CHRONIC MEMORY IMPAIRMENT AFTER CARDIAC-ARREST OUTSIDE HOSPITAL

Objectives-To evaluate the nature, prevalence, and severity of chronic memory deficit in patients resuscitated after cardiac arrest outside hospital and to determine whether such deficits are related to duratio n of cardiac arrest. Design-Case-control study. Subjects-35 survivors of cardiac arrest outside hospital and 35 controls matched for age and sex who had had acute myocardial infarction without cardiac arrest. M ain outcome measures-Subjects assessed at least two months after index event for affective state (hospital anxiety and depression scale), pr emorbid intelligence (national adult reading test), short term recall (digit recall test), and episodic long term memory (Rivermead behaviou ral memory test). Results-Cases and controls showed no difference in s hort term recall. Cases scored lower on Rivermead test than controls ( mean (SD) score out of 24 points: 17.4 (5.4) v 21.8 (2.0), P<0.001), p articularly in subtests relating to verbal and spatial memory. Moderat e or severe impairment was found in 37% of cases and in no controls. S everity of impairment of memory correlated significantly with measures of duration of cardiac arrest. This deficit was not significantly ass ociated with subjects' age, interval from index event to assessment, o ccupation, measures of comorbidity, social deprivation, anxiety or dep ression scores, or estimated premorbid intelligence. Conclusions-Clini cally important impairment of memory was common after cardiac arrest o utside hospital. Improvement in response times of emergency services c ould reduce the severity of such deficits. With an increasing numbers of people expected to survive cardiac arrest outside hospital, rehabil itation of those with memory deficit merits specific attention.