Monitoring urinary bladder temperature.

We evaluated bladder, rectal, and esophageal temperatures compared with nasopharyngeal temperatures in 12 patients who underwent cardiac surgery that required CPB. Changes in bladder temperature lagged behind those of esophageal and nasopharyngeal temperature during rapid cooling and rewarming. Changes in rectal temperature were the slowest. Bladder and rectal temperatures were similar after surgery. Monitoring bladder temperature represents the core temperature in a steady state.