PURPOSE: The neuroprotective effects and mortality benefit of mild induced hypothermia (MIH) after cardiac arrest has been demonstrated. The impact of providing this therapy to patients who have relative exclusion criteria remains unclear.
METHODS: The protocol included patients with Ventricular Tachycardia (VT)/Fibrillation (VF) or Pulseless Electrical Activity (PEA), return of circulation in under sixty minutes, and coma. MIH was started within six hours of arrival with a goal of 32 to 34 degrees (C). Patients were cooled with either ice (2 patients) or an automated cooling device (22 patients). Process measures, mortality, and neurological outcomes were compared to a similar cohort of patients who would have qualified for the protocol in the previous two years.
RESULTS: Patients included 14 men, 10 women (mean age of 60), 16 had an initial rhythm of VT or VF and 7 had PEA. All were in a coma (GCS < 6). The control group had similar baseline characteristics. Good outcomes included discharge to short term care for non-neurological reasons or discharge to home. Of those cooled, 54% had a good outcome versus 19% in the retrospective cohort. Of those who met all protocol criteria and had no relative exclusions, 83% had good outcomes vs 0% among those who had a relative exclusion. Patients presenting with PEA had a 57% survival rate. Average time to cooling in patients undergoing cardiac catheterization was 268 minutes and those without was 209 minutes.
CONCLUSION: We found that patients who had relative exclusion criteria, regardless of presenting rhythm, had poor outcomes with this therapy. We also found that the time to cooling could be improved if the cooling process were started prior to the catheterization laboratory.
CLINICAL IMPLICATIONS: The decision to provide this therapy to patients who have relative exclusion criteria may be impacted by this data. Future studies may reveal whether shortening the time to cooling within the six hour window improves clinical outcomes, and whether guidelines should support this therapy for patients with PEA.
DISCLOSURE: Carey Thomson, No Financial Disclosure Information; No Product/Research Disclosure Information