[Effect of warm bathing on short-term and 24-hour blood pressure in bedridden elderly patients]

The effects of the bathing on short-term and ciracadian blood pressure (BP) in bedridden elderly patients were investigated in 10 bedridden patients (4 male: 6 female) living in a community home. The mean age of the subjects was 78.7 years old and causes of bedridden status were cerebrovascular disease in 9 and spinal damage in one. To study the short-term hemodynamic effect of bathing, BP and pulse rate were measured every 2 minutes from 10 minutes before bathing to 14 minutes after. Blood samples were collected before and after bathing for measurements of plasma catecholamine and plasma renin activity. To study the effect of warm bathing on circadian, BP, ambulatory BP was non-invasively monitored every 15 minutes for 24 hours on days with and without bathing. In the short-term phase, BP temporally elevated when washing the body outside the bathtub accompanied with a decline soaking in warm water (38 degrees C). Plasma catecholamine did not change after warm bathing. In the study of circadian change of BP, systolic BP on days of warm bathing remained at a lower level for 12 hours after bathing compared to days without bathing. In conclusion, hypotensive effects after bathing were prolonged in the bedridden elderly patients.