Background:
Mortality data estimates show that there are about 400,000‐460,000 sudden cardiac deaths (SCDs) in the United States annually. Managing cardiac arrest patients with coma postresuscitation has been largely supportive. Following restoration of spontaneous circulation (ROSC), secondary inflammatory responses lead to further brain injury, resulting in high morbidity and mortality. Induced mild hypothermia (32°C‐34°C) has recently been shown by 2 randomized controlled trials to be neuroprotective, leading to improved neurological outcomes and survival. The International Liaison Committee on Resuscitation recommended its use in 2002, and several centers have set up formal protocols. We report our experience, identifying feasibility factors, complications, and outcomes.
Methods:
Between June and December 2006, a total of 8 cardiac arrest patients who met defined eligibility criteria were managed with a therapeutic hypothermia protocol at Unity Hospital, a suburban community hospital. We report our experience as a case series. The goals of our protocol are to achieve within 6‐8 hours of ROSC a core body temperature of 32°C‐34°C and to maintain cooling for 24 hours from initiation. Cooling was achieved with a surface cooling machine or with ice packs and a cooling blanket when the machine was unavailable. We monitored patients closely for complications during and after the protocol. Favorable outcome measure was discharge home with minimal or no neurological deficits.
Results:
There were 4 men and 4 women. Their mean age was 70 ± 14 years (range 43‐88 years). The main comorbidities were coronary artery disease (n = 6), hypertension (n = 5), diabetes mellitus (n = 5), and cardiac arrhythmia (n = 4). Cardiac arrest occurred outside the hospital (n = 6) and in the hospital (n = 2) and was witnessed in 6 of the 8 cases. The mean time from ROSC to initiation of cooling was 3 ± 1.6 hours. The mean time from ROSC to attaining the target temperature (<34°C) was 8.1 ± 4.7 hours. The mean duration of cooling was 23.8 ± 0.6 hours. The mean duration at which target temperature was maintained was 18.6 ± 4.6 hours. The median time from onset of passive rewarming to attaining a temperature > 36°C was 7.25 hours. Hypokalemia occurred in 5 patients, whereas creatinine levels worsened in 3 patients. Two patients survived and were discharged home with little or no neurological deficits.
Conclusions:
Induced hypothermia is feasible and not associated with significant complications. We had excellent outcomes for 2 of the 8 patients in this case series. Characteristics peculiar to these 2 patients that could have contributed to their favorable outcome include younger age (48 and 64 years), minimal comorbidities, and relatively higher score on the Glasgow coma scale at the time of admission (GCS of 5).
Author Disclosure:
A. Aghenta, None; A. Osowo, None; C. Palacio, None; V. Das, None; J. Hessney, None.