Early predictors of outcome in comatose survivors of ventricular fibrillation and non-ventricular fibrillation cardiac arrest treated with hypothermia: A prospective study* Mauro Oddo, MD † ; Vincent Ribordy, MD; Franc ¸ ois Feihl, MD; Andrea O. Rossetti, MD; Marie-Denise Schaller, MD; Rene ´ Chiole ´ ro, MD; and Lucas Liaudet, MD T herapeutic hypothermia (TH) has been convincingly shown to improve outcome in a se- lected subset of patients with cardiac arrest (CA) due to ventricular fi- brillation (VF) and without sustained pos- tresuscitation circulatory shock (1– 4). However, in clinical practice, these rep- resent a minority of patients and indeed indications for TH are narrowly defined (5–7). This might at least in part contrib- ute to explain why TH is still underused (8). In order to better define the role of TH in general clinical setting and to ex- pand its appropriate utilization to a larger proportion of patients, additional studies including unselected heterogeneous co- horts of comatose survivors of CA of var- ious etiologies are needed. We therefore designed a prospective study including all patients admitted to our intensive care unit (ICU) for post-CA coma. All patients were treated with a uniform protocol of TH. Several predefined clinical vari- ables obtained at admission, including duration of CA (defined as the time from collapse to return of spontaneous circulation), initial arrest rhythm (VF or non-VF) and hemodynamic status (presence or absence of postresuscita- tion circulatory shock), were analyzed and their potential correlation with clinical outcome at hospital discharge was evaluated. METHODS Patient Population This prospective study was conducted be- tween December 2004 and October 2006, in a 32-bed adult medico-surgical ICU of a univer- sity hospital. Full approval was given by our institutional ethic committee. Patient popula- tion consisted of all consecutive subjects, aged 80 yrs admitted for persistent coma follow- ing out-of-hospital cardiac arrest (OHCA). Out-of-hospital resuscitation was delivered by an emergency medical team, which included one trained physician, according to the Amer- ican Heart Association guidelines published in 2000 (9) and, since January 2006, to the 2005 revised version of these guidelines (10). Pa- tients were initially treated in the emergency room and, after stabilization, were rapidly transferred to the ICU. Therapeutic Hypothermia TH was started immediately on admission to the emergency room and was administered according to our local, previously described *See also p. 2456. From the Department of Critical Care Medicine (MO, VR, M-DS, RC, LL), Interdisciplinary Emergency Center (VR), Division of Pathophysiology (FF), Depart- ment of Neurology (AOR), Lausanne University Medical Center and Faculty of Biology and Medicine, Lausanne, Switzerland. For information regarding this article, E-mail: Mauro.Oddo@chuv.ch † Current address: Department of Neurosurgery, Clinical Research Division, University of Pennsylvania Medical Center, 3rd Floor Silverstein Building, 3400 Spruce Street, Philadelphia, PA 19104. The authors have not disclosed any potential con- flicts of interest. Copyright © 2008 by the Society of Critical Care Medicine and Lippincott Williams & Wilkins DOI: 10.1097/CCM.0b013e3181802599 Objectives: Current indications for therapeutic hypothermia (TH) are restricted to comatose patients with cardiac arrest (CA) due to ventricular fibrillation (VF) and without circulatory shock. Additional studies are needed to evaluate the benefit of this treatment in more heterogeneous groups of patients, including those with non-VF rhythms and/or shock and to identify early predictors of outcome in this setting. Design: Prospective study, from December 2004 to October 2006. Setting: 32-bed medico-surgical intensive care unit, university hospital. Patients: Comatose patients with out-of-hospital CA. Interventions: TH to 33  1°C (external cooling, 24 hrs) was administered to patients resuscitated from CA due to VF and non-VF (including asystole or pulseless electrical activity), inde- pendently from the presence of shock. Measurements and Main Results: We hypothesized that simple clinical criteria available on hospital admission (initial arrest rhythm, duration of CA, and presence of shock) might help to identify patients who eventually survive and might most benefit from TH. For this purpose, outcome was related to these pre- defined variables. Seventy-four patients (VF 38, non-VF 36) were included; 46% had circulatory shock. Median duration of CA (time from collapse to return of spontaneous circulation [ROSC]) was 25 mins. Overall survival was 39.2%. However, only 3.1% of patients with time to ROSC >25 mins survived, as compared to 65.7% with time to ROSC <25 mins. Using a logistic regression analysis, time from collapse to ROSC, but not initial arrest rhythm or presence of shock, independently predicted survival at hospital discharge. Conclusions: Time from collapse to ROSC is strongly associ- ated with outcome following VF and non-VF cardiac arrest treated with therapeutic hypothermia and could therefore be helpful to identify patients who benefit most from active induced cooling. (Crit Care Med 2008; 36:2296 –2301) KEY WORDS: hypothermia; cardiac arrest; indications; predictors; outcome 2296 Crit Care Med 2008 Vol. 36, No. 8