Monitoring urinary bladder temperature in the intensive care unit: state of the science.

Body temperature of patients in critical care units can be monitored with a variety of devices and at a variety of body sites. In recent years, monitoring of urinary bladder temperature has become more common. Temperature-sensing indwelling urinary catheters allow continuous drainage of urine and continuous measurement of body temperature. This article provides a comprehensive and critical review of research undertaken in intensive care units to compare body temperatures measured in the urinary bladder with temperatures measured at a core site, the pulmonary artery. The studies support the use of urinary bladder temperature as a reliable index of core temperature during times of thermal stability. For critically ill patients who are already under considerable stress and whose condition necessitates the use of an indwelling urinary catheter, bladder temperature monitoring is an easy and convenient method that eliminates the need to use alternative sites. Further studies on the effects of shivering and urinary flow rate on temperatures measured in the bladder in critical care patients are needed. The economics of monitoring urinary bladder temperature also should be studied.