Prehospital intranasal evaporative cooling for out-of-hospital cardiac arrest: a pilot, feasibility study.

Intranasal evaporative cooling presents a novel means of initiating therapeutic hypothermia after an out-of-hospital cardiac arrest (OHCA). Few studies have evaluated the use of intranasal therapeutic hypothermia using the Rhinochill device in the prehospital setting. We sought to evaluate the use of Rhinochill in the Physician Response Unit of London's Air Ambulance, aiming to describe the feasibility of employing it during prehospital resuscitation for OHCA. We prospectively evaluated the Rhinochill device over a 7-month period. Inclusion criteria for deployment included: age above 18 years, Physician Response Unit on-scene within maximum of 10 min after return-of-spontaneous circulation (ROSC), witnessed OHCA or unwitnessed downtime of less than 10 min, pregnancy not suspected, normal nasal anatomy, and likely ICU candidate if ROSC were to be achieved. Thirteen patients were included in the evaluation. The average time from the 999 call to initiation of cooling was 39.5 min (range 22-61 min). The average prehospital temperature change in patients who achieved ROSC was -1.9°C. Patients were cooled for an average of 38 min prehospital. In all cases, the doctor and paramedic involved with the resuscitation reported that the Rhinochill was easy to set up and use during resuscitation and that it did not interfere with standard resuscitation practice. Intranasal evaporative cooling using the Rhinochill system is feasible in an urban, prehospital, doctor/paramedic response unit. Cooling with Rhinochill was not found to interfere with prehospital resuscitation and resulted in significant core body temperature reduction. Further research on the potential benefit of intra-arrest and early initiation of intranasal evaporative cooling is warranted.