The Respiratory and Cardiovascular Response to Immersion in Cold and Warm Water

Abstract

During their first few minutes of immersion in stirred water at 5 and 150 C. the pulmonary ventilation of twelve unclothed men was high, and their end-tidal PCO2 fell. The pCO2 then returned to or a little above its original level but did not greatly exceed it even in working experiments lasting 20 min. in water at 50 C. or 40 min. in water at 150 C. Although work reduced or reversed the initial fall in pCO2, these results therefore do not bear out predictions that the pCO2 would rise to dangerous levels during hard work in cold water, at least in immersions of moderate duration.In water at 37.80 C. the men's heart rates rose steadily, in water at 250 C. they fell and remained low, and in water at 5 and 150 C. they rose and then fell. Repeated immersion at 150 C. reduced or abolished the early respiratory and heart rate responses to immersion and the metabolic response, but did not significantly increase the falls in rectal temperature. Clothing also reduced the reflex responses to immersion. A number of ventricular extrasystoles were observed during the first 2 min. of immersion in water at 150 C., and it is suggested that ventricular fibrillation due to increased venous and arterial pressures, adrenaline, and hyperventilation, may be responsible for some cases of sudden death in cold water. THIS paper describes observations on the end-tidal pCO2, pulmonary ventilation, heart rate, and electrocardiographs of twelve men during immersion in water at temperatures between 5 and 37.80 C. Cotes [1954 and 1955] has reported that the pulmonary ventilation of a man could be predicted from his alveolar pCO2 and deep body temperature, and anticipated that CO2 would accumulate in the body to reach dangerous concentrations during hard work in cold water.Sudden death in cold water without drowning is generally [Simpson, 1958] attributed to vagal arrest of the heart following inhalation of cold water into the naso-pharynx and glottis. However, it has seemed possible that ventricular fibrillation might be responsible for some of these cases; an increase in venous pressure may follow sudden exposure to cold [Bondurant, Hickam and Isley, 1957; Keatinge and McCance, 1957] and a rise in filling pressure may precipitate ventricular fibrillation in isolated hearts [Keatinge, 1959], while adrenaline is known sometimes to cause ventricular fibrillation after chloroform [Levy, 1914] and to facilitate it without chloroform in isolated hearts [Goodford, 1958].The effect of adaptation by repeated immersion in cold water has also been assessed, since the heart rate and blood pressure responses to the immersion of a hand in ice water [Glaser and Whittow, 1957] are reduced by repetition. The design of the experiments and the subjects have been described in the preceding paper.*

A water-filled body plethysmograph for the measurement of pulmonary capillary blood flow during changes of intrathoracic pressure

“…One of the possible explanations for this decrease was that hyperventilation preceded the measurements, resulting in lowered body stores of CO2. In the studies of Keatinge and Evans (11), minute volume of ventilation rose slightly after immersion in 350C water (up to the neck), but returned to normal after a couple of minutes. In our study, the measurement of CO2 output was done after at least 20 min of immersion.…”

The effect of repeated daily exposure to cold and of improved physical fitness on the metabolic and vascular response to cold air

“…Burton (1941) reported that while heavily-clothed men generally had a poor metabolic response to cold, heavily clothed men used to life in a cold climate had a larger one, and Keatinge (1960) observed that exposure of men to air at 50 C for 160 min increased their metabolic response to a 30 minimmersion at 150 C later in the day. On the other hand the metabolic response of men immersed for 20 min in water at 150 C was reduced by repeated immersion at this temperature (Keatinge, 1959;Keatinge & Evans, 1961) and Scholander, Hammel, Hart et al (1958) observed lower metabolic rates and larger falls of skin and rectal temperatures during the night in aborigines than in Europeans sleeping out in Australia, where night temperatures were low but day temperatures were high. These various findings could be explained as adjustments made by the central nervous system, not necessarily at conscious level, in the light of experience obtained during acclimatization.…”

“…The increase in the early metabolic response to cold often observed, together with the decrease in metabolic rate at the end of the day always observed, after daily exposure to cold in the present experiments, can hardly be ascribed to anything other than central nervous adjustments of this kind. 216 W. B. KEATINGE ACCLIMATIZATION TO COLD This interpretation of changes in the metabolic response is in keeping with certain changes observed in other responses to cold; the heart rate and blood pressure response to immersion of a hand for 60 sec in ice-water, a painful cold stimulus, is reduced by repetition, probably through the central nervous system (Glaser & Whittow, 1957;Glaser, Hall & Whittow, 1959), and the respiratory and heart-rate, as well as the metabolic, responses of men to immersion for 20 min in water at 150 C are reduced by repeated immersion at this temperature (Keatinge & Evans, 1961).…”

“…These might be explained in part by the observation that different types of quite brief exposure to cold in the laboratory may either decrease (Keatinge, 1959;Keatinge & Evans, 1961) or increase (Keatinge, 1960) the metabolic response to cold, probably through central nervous adjustments. The present experiments were therefore designed to show whether more prolonged exposure to cold caused similar changes in metabolic response, and whether physical training, which generally accompanies field acclimatization, alters men's subsequent metabolic response to cold.…”

The Physiological Response of Immersion in Cold Water and Cooling Rates During Swimming in a Group of Children Aged 10–11 Years

“…The human physiological response to acute cold exposure has been well documented, and substantial research has been conducted into adult thermal responses to initial and prolonged immersion in cold water (Golden & Tipton, 2002;Keatinge & Evans, 1961;Tipton, 1989). It is well recognized that the initial cold shock response seen in adults upon immersion includes uncontrollable respiratory gasping and increased cardiac workload that are particularly hazardous.…”