Blood gas analyses of hibernating hamsters and dormice

Summary Blood gases were measured in hibernating and hypothermic animals as a biological model of clinical hypothermia. Blood gas analyses from hamsters and dormice were carried out with the aid of permanent arterial catheters during normothermia and hibernation. In golden hamster pH increased from 7.30 to 7.46 during hibernation andPaCO₂ decreased from 59.7 to 40.5 mm Hg. In dormice pH increased from 7.24 to 7.44 andPaCO₂ decreased from 38.5 to 27.4 mm Hg. The actual bicarbonate concentration increased from 29 to 52 mMol in golden hamsters and from 16 to 34 mMol in dormice during hibernation.In experiments with induced hypothermia in golden hamsters under ketamine-anaesthesia there was no correlation between temperature andPaCO₂. Despite the slight decrease inPaCO₂ during hibernation we conclude thatPaCO₂ rather than total carbon dioxide content is held constant when temperature is changed. During clinical hypothermia it will probably be safe to keepPaCO₂ constant.These investigations were supported by the Swiss National Research Foundation