The Circulatory Dynamics Reactions of Elderly Community Residents during Bathing: Differences Resulting from Immersion Methods and Temperatures / 日本温泉気候物理医学会雑誌

ABSTRACT

  【Purpose】The number of deaths in the bathtub in the home is increasing year by year, of which about 90% are people over 65 years old. The purpose of this study was to verify the hypothesis that the effect on the circulatory dynamics would be less if one took a half-body bath first and then a whole- body bath after a certain period of time, rather than suddenly taking a whole- body bath.  【Methods】The subjects were ten healthy community elderly men (70.3 ± 4.0 years old). The subjects were bathed at 39°C and 41°C, respectively, with two immersion methods of a 6-min whole body bath and a 3 min whole-body bath after a 3 min half-bath (6 min total). Measured items were systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse (PR), oxygen saturation (SpO2), and forehead skin temperature. The subjective thermal sensation and comfort were also confirmed verbally. Measurements were carried out in the sitting posture before bathing, within 1 min after bathing, after 2 min, 3 min, and 5 min, just after the bath, and 5 min after sitting rest.   【Results】In both SBP (p = .010) and DBP (p = .019), the interaction between bathing conditions and measurement time was significant. SBP was greatly affected by temperature regardless of whether or not stepped immersion was used, and blood pressure decreased immediately after bathing at 41°C. DBP showed a significant decrease during bathing at 41°C compared with the whole-body bath after half-body bathing.  【Discussion】The SBP was markedly decreased immediately after taking a bath at a temperature of 41°C regardless of whether or not the subject was gradually immersed. It is thought that the condition is similar to that of orthostatic hypotension. Furthermore, DBP also showed a decrease of 10 mmHg or more, corresponding to changes during orthostatic hypotension, when bathing only with a whole-body bath at a temperature of 41°C. On the other hand, in the whole-body bath after half-body bathing, the decrease in DBP was less than 10 mmHg even at 41°C.