Hypothermic Carotid Arterial Flush for Induction of Selective Cerebral Hypothermia during Cardiac Arrest

ABSTRACT

PURPOSE: Hypothermia has been demonstrated to protect the brain from reperfusion injury in patients suffering from cardiac arrest. We hypothesized that infusion of normal saline at 4 degrees C into the carotid artery (hypothermic carotid arterial flush, HCAF) during cardiac arrest would achieve selective cerebral hypothermia during cardiac arrest and cardiopulmonary resuscitation (CPR), without a detrimental effect on the rate of return of spontaneous circulation (ROSC) or significant impairment of cardiopulmonary function after ROSC. METHODS: Ventricular fibrillation was induced in 18 dogs weighing 12~18 kg, and circulatory arrest was maintained for 9 minutes. The subjects were then resuscitated using open cardiac massage. Group I (n=6) received no normal saline, while the dogs of group II (n=6) and group III (n=6) received infusions of 15 ml/kg and 30 ml/kg of normal saline solution, respectively, at 4 degrees C into both carotid arteries (cephalad) via 18 gauge catheters. RESULTS: Tympanic temperature decreased from 37.7 (37.5~37.7) degrees C to 34 degrees C within 1.2 (1~2) min and 1.0 (1~2) min from the start of HCAF in groups II and III, respectively. Thereafter, tympanic temperatures were maintained below 34 degrees C to 7.7 (1.5~14.5) min and 21.2 (12~37) min, respectively, from the start of HCAF in groups II and III. There were no significant differences in CPR-related variables or post-ROSC hemodynamic and laboratory variables between the two groups. CONCLUSION: HCAF rapidly induces selective cerebral hypothermia without detrimental effects on the rate of ROSC or significant impairment of cardiopulmonary function after ROSC.