Good neurological recovery at ICU discharge of asystole patients treated with induced mild hypothermia

Induced mild hypothermia therapy (MHyT) improves neurological outcome in postresuscitation cardiac arrest patients with ventricular fibrillation/tachycardia (VF/VT). Patients with asystole were excluded from earlier studies due to poor overall outcome [1, 2]. The present study enrolled both patients with asystole or VT/VF; one of the objectives was to assess neurological function at ICU discharge.

A prospective multicenter single-arm registry in 49 patients with witnessed cardiac arrest who were selected for MHyT. Patients had to be ≥ 18 years old and unconscious at ICU/emergency room admission (GCS < 8), with a time interval between cardiac arrest and initiation of MHyT treatment <6 hours. Informed consent was obtained from the patient or legal representative. Neurological status was documented upon emergency room arrival, during MHyT treatment, at ICU discharge and at hospital discharge as measured by the Glasgow Outcome Scale (GOS). Temperature measurements were continuously taken throughout the MHyT treatment via bladder catheter. For the MHyT treatment the Deltatherm^® device (KCI, San Antonio, TX, USA) was used.

Of the 49 patients included in the registry 31 (63%) had VF/VT and 17 (35%) had asystole as first rhythm. In one patient (2%) the rhythm was unknown. Good neurological recovery at ICU discharge (GOS 5 and 4) was seen in 22 (45%), three patients (6%) were neurologically impaired (GOS 3), six patients (12%) were in a vegetative state (GOS 2) and 16 (33%) of the patients died. In two patients (4%) the neurologic outcome was unknown. Good neurological recovery was seen in 48% (n = 15) of patients with VF/VT and in 41% (n = 7) of patients with asystole.

MHyT improves neurological outcome in patients with witnessed cardiac arrest regardless of the initial rhythm. Favorable results in VT/VF patients were similar to preceding studies [1, 2]. Hypothermia also appears to provide neurological protection in patients presenting with asystole.