Cardiac arrest: few patients in a coma post-arrest live longer than a month

Clinical bottom line (level 4)

  1. 4% of patients who are in a coma following a cardiac arrest are alive after one month.
  2. A lack of motor response to pain after 16 hours helps predict mortality.
Edgren et al: Lancet 1994; 343: 1055-1059
Expires October 2003

The study

Inception cohort study with unblinded, unobjective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: 12 acute hospitals, USA and Europe

262 patients (aged mean 58, 75% male) with cardiac arrest who were comatose (no purposeful motor response to painful stimuli 10 minutes after restoration of spontaneous circulation with a pulse of >90 mmHg)

Excluded if
  • responded purposefully to painful stimuli
  • arrest secondary to intracranial lesions
  • infants
  • terminal condition



    • Factors studied:
  • Glasgow Coma Score, pupil light response, seizures, spontaneous breathing


    • Patients were resuscitated using ACLS guidelines, and then received a standardised intensive care protocol of brain-orientated life-support. Half of the patients were randomly assigned to receive 30 mg/kg thiopentone, started within 50 minutes of study entry.

    Multivariate logistic regression analysis performed on prognostic factors.

    ?100% (no information on any loss to follow-up) followed for 4 weeks
    Outcomes studied:
  • survived one month

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)    		 NNF
    (95% CI)
    survived one month 4 weeks 11/262 4.2%
    (1.8% to 6.6%)    		 23
    (15 to 56)

    • Only lack of motor response to pain later than 16 hours was independently associated with a poor outcome (no odds ratio provided)

    Comments

    1. The study design focuses to just a part of the problem (cerebral performance instead of overall performance, "best performance at any time" as neurological end-point), which must be taken into account.
    2. No comatose patients were alive after a year, though overall survival rates were 21.5%.
    3. 75% of arrests were outside hospital.

    Citation

    1. Edgren E, Hedstrand U, Kelsey S, et al: Assessment of neurological prognosis in comatose survivors of cardiac arrest. Lancet 1994; 343: 1055-1059
    Contributor: Chris Ball and Clare Wotton, October 1999
    Reviewer: Luis Ruiz Del Fresno

    Clinical Question.
    Patient cardiac arrest
    Intervention or Exposure comatose
    Outcome poor neurological outcome, mortality