Safety and feasibility of nasopharyngeal evaporative cooling in the emergency department setting in survivors of cardiac arrest☆

Abstract 

Aim

Mild therapeutic hypothermia improves survival and neurologic recovery in primary comatose survivors of cardiac arrest. Cooling effectivity, safety and feasibility of nasopharyngeal cooling with the RhinoChill device (BeneChill Inc., San Diego, USA) were determined for induction of therapeutic hypothermia.

Methods

Eleven emergency departments and intensive care units participated in this multi-centre, single-arm descriptive study. Eighty-four patients after successful resuscitation from cardiac arrest were cooled with nasopharyngeal delivery of an evaporative coolant for 1h. Subsequently, temperature was controlled with systemic cooling at 33°C. Cooling rates, adverse events and neurologic outcome at hospital discharge using cerebral performance categories (CPC; CPC 1=normal to CPC 5=dead) were documented. Temperatures are presented as median and the range from the first to the third quartile.

Results

Nasopharyngeal cooling for 1h reduced tympanic temperature by median 2.3 (1.6; 3.0)°C, core temperature by 1.1 (0.7; 1.5)°C. Nasal discoloration occurred during the procedure in 10 (12%) patients, resolved in 9, and was persistent in 1 (1%). Epistaxis was observed in 2 (2%) patients. Periorbital gas emphysema occurred in 1 (1%) patient and resolved spontaneously. Thirty-four of 84 patients (40%) patients survived, 26/34 with favorable neurological outcome (CPC of 1–2) at discharge.

Conclusions

Nasopharyngeal evaporative cooling used for 1h in primary cardiac arrest survivors is feasible and safe at flow rates of 40–50L/min in a hospital setting.

Keywords: Cardiac arrest, Hypothermia, Cooling devices