Oxygen uptake and cardiovascular responses in control adults and acute myocardial infarction patients during bathing.

Physiological responses before, during, and after three types of baths were determined in 18 patients who were 5 to 17 days postinfarction and 22 control adults. In the patients, oxygen consumption (VO2) averaged 6, 7, and 7 ml/kg/min, peak heart rate 105, 108, and 112 beats per minute, and rate pressure product 115, 120, and 111 for basin, tub, and shower bathing, respectively. Oxygen consumption during bathing was less than 3 times resting levels. The patients had a significantly lower VO2 during bathing than the control subjects. The patients' peak heart rates were higher than anticipated for the level of exertion, and sometimes exceeded the target heart rates used in predischarge testing. Peak heart rate and occurrence of dysrhythmia did not differ significantly between the three types of baths. In the women patients, rate pressure product was significantly higher after tub bath than after basin bath or shower. The subjects had no cardiovascular symptoms during bathing, rated all three baths as light exertion, and disliked the basin bath. The data show that the physiologic costs of the three types of baths are similar, differences in responses to bathing seem more a function of subject variability than bath type, and many cardiac patients can take a tub bath or shower earlier in their hospitalization. However, more research is needed to predict patients likely to have an exaggerated response to bathing and to develop clear guidelines for bath method selection and progression.