Intranasal Cooling Improves Survival Following Cardiac Arrest

The patients were randomized to either intranasal cooling with the RhinoChill system, along with standard advanced cardiac life support (ACLS) care (96 patients), or ACLS alone (104 patients), until they were either resuscitated or reached hospital, at which stage patients in both groups were cooled.

The results showed that the target tympanic temperature of 34 °C, used as an approximation of brain temperature, was reached three hours earlier in the group receiving prehospital cooling; target core body temperature was reached two hours earlier. Among patients surviving as far as hospital admission, 47% of patients who were cooled survived to hospital discharge, compared with only 31% of those who had not been cooled. Survival rates in the 75% of patients who received CPR within ten minutes of collapse were 59% and 29% respectively. The researchers also found that 37% of those patients cooled intranasally during the arrest surviving neurologically intact, compared with only 21% of those not cooled in the field; neurologically intact survival rates in patients who received CPR within ten minutes of collapse were 46% and 18% respectively, a very significant difference. The study was published in the August 17, 2010, issue of Circulation.

"We believe that this study demonstrates that making every attempt to initiate both CPR and intra-arrest cooling as early as possible in the resuscitation process should be adopted,” said lead author Maaret Castren, M.D., of the department of emergency medicine. "A strength of this approach appears to be its relative noninvasiveness and ease of administration. It may prove an ideal device for the emergency medical services setting.”

For the study the researchers used the RhinoChill Intra-Nasal Cooling System, a product of BeneChill (San Diego, CA, USA), which uses a noninvasive nasal catheter to spray a rapidly evaporating coolant liquid into the nasal cavity, which serves as a "heat exchanger” that lies directly under the brain; cooling the brain reduces its need for oxygen and slows the damage processes. The system's portability and ease of use mean that cooling of the brain can be initiated much sooner after a cardiac arrest than with traditional devices, which cannot be used until the patient reaches hospital.

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