title: Electrocardiographic changes during surface-induced deep hypothermia. The influence of ether, halothane, carbon dioxide, and perfusion rewarming.
abstract: The influence of halothane, ether, carbon dioxide, and perfusion rewarming on the electrocardiogram was studied in 37 dogs subjected to surface-induced deep hypothermia. Significant anesthetic-related differences in P-R, QRS, Q-T and R-R intervals during cooling were not apparent; however, reduced arterial pressure, ventricular fibrillation, and a greater tendency for bradycardia requiring supportive measures were noted at low temperatures with halothane anesthesia. The use of 95% O2/5% CO2 significantly reduced the QTc at low temperatures; Other phenomena, including the occurrence and significance of J waves, are discussed. The relationship of the electrocardiogram to clinical and pathological results was evaluated and indicates that (1) properly managed resuscitation (manual massage and defibrillation) is not a serious hazard, (2) ether in 100% oxygen is the agent of choice for surface-induced deep hypothermia with prolonged circulatory arrest, and (3) halothane may be used in a procedure combining surface cooling and perfusion rewarming if given in a mixture of oxygen and carbon dioxide.
mesh_terms: D000769:Anesthesia, Inhalation; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology* / Q000517:prevention & control; D001919:Bradycardia / Q000517:prevention & control; D002245:Carbon Dioxide / Q000494:pharmacology*; D006348:Cardiac Surgical Procedures; D004285:Dogs; D005019:Ethyl Ethers / Q000494:pharmacology*; D005260:Female; D006221:Halothane / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006358:Hot Temperature; D007036:Hypothermia, Induced; D008297:Male; D010477:Perfusion; D014693:Ventricular Fibrillation / Q000517:prevention & control
chemical_list: D005019:Ethyl Ethers; D002245:Carbon Dioxide; D006221:Halothane