Cardiac Arrest Temperature: The Effect of Ethyl Alcohol and Carbon Dioxide on Rats, Guinea‐pigs and Isolated Rat Hearts

Abstract

1. Previous clinical and experimental reports have suggested that the systemic administration of ethyl alcohol permits lower body temperatures before the onset of hypothermic cardiac arrest. 2. In the investigations described here, the effect of ethyl alcohol on the temperature at which cardiac arrest occurred in rats, guinea-pigs and isolated rat hearts was studied. Comparison was also made of the difference between pulmonary ventilation with air and with 5% carbon dioxide in oxygen. 3. The results demonstrated that both the administration of ethyl alcohol and ventilation with 5% carbogen reduced the cardiac arrest temperature of rats. Ethyl alcohol did not influence the cardiac arrest temperature of guinea-pigs nor of isolated rat hearts.

A Study of the Thermogenic Effect of Ethanol in the Hypothermic Rat

“…It may be argued that the fact that the rats were paralysed and anaesthetized may have prevented them from responding to a metabolic substrate. However, the studies by White Table 1 & Nowell (1965) and Duthie & White (1977), in which they reported the failure of alcohol to induce rapid cooling, were conducted on similarly anaesthetized rats. Furthermore, the relatively small doses of both barbiturate and relaxant would be unlikely to inhibit metabolic pathways to such an extent that they became totally incapable of responding to the addition of an energy source.…”

“…White & Nowell (1965) reported that an ethanol treated group of rats cooled more slowly than a control group, and this was confirmed by Duthie & White (1977). In an attempt to explain this paradoxical situation in which cooling was not enhanced by the cutaneous vasodilatation, White & Nowell (1965) postulated that ethanol, with its high calorific value, might exert a thermogenic effect in hypothermic animals.…”

Cardiac Arrest Temperature: The Effect of Ethyl Alcohol and Carbon Dioxide on Baboons

“…Previous studies (White and Nowell, 1965;Duthie and White, 1977) have supported the view that ethyl alcohol protects the rat heart from the effects of hypothermia, with the result that cardiac arrest occurs at a lower temperature than normal. It has been shown also that high inspired carbon dioxide concentrations augment the protective effect of ethanol on the rat heart, and allow still lower temperatures to be achieved before the occurrence of cardiac arrest (Duthie and White, 1977).…”

Changes in the myocardium and skeletal muscle in guinea pigs in cold exposure with and without ethanol

“…The severity and type of the lesion was studied using proven muscle stainings and examining the release of muscle enzymes into the serum. In addition, the effect of ethanol on the development of the lesions was tested, as many studies have shown that ethanol can keep the heart beating in deeper hypothermia than could be survived otherwise (McGregor et al 1966;Webb et al 1968;Duthie and White 1977).…”