Hypothermia for cardiac arrest

CTL-Derived Granzyme B Participates in Hippocampal Neuronal Apoptosis Induced by Cardiac Arrest and Resuscitation in Rats

Hippocampal neuronal apoptosis is a devastating consequence of cardiac arrest (CA) and subsequent cardiopulmonary resuscitation (CPR). In this study, we assessed the contribution of cytotoxic T lymphocyte (CTL)-derived toxic mediator granzyme B (Gra-b) to the hippocampal neuronal apoptosis following CA/CPR in rats. Rats that experienced CA/CPA presented with cytosomal shrinkage, dense cytoplasm, and intensive eosinophilic staining in the CA1 region of dorsal hippocampus. CA/CPR rats also exhibited inability in spatial navigation and a local infiltration of peripheral CD8+ T cells into the hippocampus. The protein levels of Gra-b, cleaved Caspase-3, and cleaved PARP1 were significantly elevated in rats undergoing CA/CPR. Pretreatment with Gra-b inhibitor suppressed Gra-b release, attenuated hippocampal neuronal apoptosis, as well as improved cognitive impairment. Together, this study indicates that CTL-derived Gra-b is involved in the CA/CPR-induced neuronal apoptosis, and pharmacological manipulation of Gra-b may represent a novel avenue for the treatment of brain injury following CA/CPR.

Neurologic complications of cardiac arrest

Cardiac arrest is a common and serious medical emergency affecting upwards of 450000 Americans on an annual basis. It causes a substantial strain on the physical and financial resources of the medical system. The optimal management of patients requires the close collaboration of multiple specialists, including first responders, intensivists, cardiologists, and neurologists. The role of the neurologist for the post-arrest patient is to assist in management to minimize brain injury as well as to prognosticate long-term outcomes to help guide therapy decisions of families and physicians. This review focuses on epidemiologic data, current management recommendations, clinical and ancillary testing to suggest long-term prognosis, and common complications of cardiac arrest. Particular attention has been paid to updates, including therapeutic hypothermia, since this topic was last reviewed in 1993.

Therapeutic hypothermia following emergent coronary artery bypass grafting after failed percutaneous coronary intervention in a comatose post-cardiac arrest patient

We report the case of 60-yr-old female in which therapeutic hypothermia (TH) was successfully induced maintaining the target temperature of 34℃ for 12 hr despite a risk of hypothermia-induced coagulation abnormalities following an emergent coronary artery bypass grafting (CABG) due to failed percutaneous coronary intervention, who suffered a cardiac arrest. Emergent CABG may be a relative contraindication for TH in post-cardiac arrest patients because hypothermia may increase the risk of infection and bleeding. However, the possibility of an improved neurologic outcome outweighs the risk of bleeding, although major surgery may be a relative contraindication for TH.

A comparison between head cooling begun during cardiopulmonary resuscitation and surface cooling after resuscitation in a pig model of cardiac arrest

OBJECTIVE

Employing transnasal head-cooling in a pig model of prolonged ventricular fibrillation, we compared the effects of 4 hrs of head-cooling started during cardiopulmonary resuscitation with those of 8 hrs of surface-cooling started at 2 hrs after resuscitation on 96-hr survival and neurologic outcomes.

DESIGN

Prospective controlled animal study.

SETTING

University-affiliated research laboratory.

SUBJECTS

Domestic pigs.

INTERVENTIONS

Twenty-four male pigs were subjected to 10 min of untreated ventricular fibrillation followed by 5 min of cardiopulmonary resuscitation. In the head-cooling group, hypothermia was started with cardiopulmonary resuscitation and continued for 4 hrs after resuscitation. In the surface-cooling group, systemic hypothermia with a cooling blanket was started, in accord with current clinical practices, at 2 hrs after resuscitation and continued for 8 hrs. Methods in the control animal studies were identical except for temperature interventions.

MEASUREMENTS AND MAIN RESULTS

All animals were resuscitated except for one animal in each of the surface-cooling and control groups. After 5 min of cardiopulmonary resuscitation, jugular vein temperature was significantly decreased in the head-cooled animals. However, there were no differences in pulmonary artery temperatures among the three groups at that time. Nevertheless, both head-cooled and surface-cooled animals had an improved 96-hr survival after resuscitation. Significantly better neurologic outcomes were observed in early head-cooled animals in the first 3 days after resuscitation.

CONCLUSION

Early head-cooling during cardiopulmonary resuscitation continuing for 4 hrs after resuscitation produced favorable survival and neurologic outcomes in comparison with delayed surface-cooling of 8 hrs duration.