Exercise and extracorporeal blood cooling during hemodialysis

Four stable patients with age average of 49.9±7.7 years were studied during 22 treatments that either maintained T_dia at 35.9 °C±0.1 °C or provided maximum extracorporeal cooling (T_dia = 34.8 °C±0.8 °C) to maintain a constant arterial blood temperatures. The energy expenditures of patients who exercised for 1 hr at a resistance of 21±5 W on a stationary bicycle ergometer increased from 117±38 W to 338±116 W. The exercise produced a small but significant decrease in the relative blood volume changes that reversed at the end of the exercise. Intradialytic exercise was well tolerated, especially when T_dia was lowered. The hemodynamic stress to dissipate excess heat through the cutaneous circulation was reduced and the blood pressure stability was improved.