Therapeutic hypothermia (TH) and targeted temperature management improve neurologic recovery, and survival for patients resuscitated from witnessed out-of-hospital ventricular tachycardia (VT) and ventricular fibrillation (VF) cardiac arrest. The American Heart Association recently gave a class IIb recommendation for the use of TH for non-VT/VF and unwitnessed arrests. We explored changes in baseline characteristics, resource use, and outcomes after expanding indications for TH at our institution based on these guidelines. Fifty-six consecutive patients treated with TH for out-of-hospital cardiac arrest were retrospectively evaluated based on whether they received treatment before (protocol 1) or after (protocol 2) broadening inclusion criteria. In protocol 1, TH was indicated after a witnessed VT/VF arrest. In protocol 2, TH was indicated for unwitnessed arrests, pulseless electrical activity, or asystole. Both populations undergoing TH had similarly extensive medical comorbidities and consumed considerable hospital resources. Overall, 64% of the patients from both protocols died in the hospital, although nominally lower mortality was seen in patients treated under protocol 1 compared with protocol 2 (59% vs. 67%, P = 0.57). Lower mortality was observed after VT/VF than after pulseless electrical activity or asystole (47% vs. 93% vs. 56%, P = 0.017). No patient survived following an unwitnessed arrest, and age (odds ratio per 10 years = 2.59; 95% confidence interval, 1.34–4.81) was independently associated with increased mortality. In an evolving field where best practice is still poorly defined, these data, along with future prospective studies in larger populations, should help to enhance care delivery and optimize cost-effectiveness strategies.
From the *Department of Internal Medicine, University of North Carolina, Chapel Hill, NC; †Division of Cardiology and Pulmonary & Critical Care, University of North Carolina Center for Heart and Vascular Care, Chapel Hill, NC; ‡Kaiser Permanente, Atlanta, GA; §Department of Emergency Medicine, University of North Carolina, Chapel Hill, NC; ¶Department of Pharmacy, Loyola University Medical Center, Maywood, IL; and ‖Department of Pharmacy Practice and Science, University of Maryland, School of Pharmacy, Baltimore, MD.
Reprints: Jason N. Katz, MD, MHS, UNC Center for Heart and Vascular Care, 160 Dental Circle, CB 7075, Burnett-Womack Bldg, 6th Floor, Chapel Hill, NC 27599. E-mail: firstname.lastname@example.org.