Comparison of temperature measurements in bladder, rectum and pulmonary artery in patients after cardiac surgery

In many patients in the intensive care unit (ICU) continuous temperature monitoring is performed with rectal probes. Currently there are more options to measure temperature in critically ill patients. Since bladder catheters are routinely used in the majority of ICU patients, using bladder temperature (Tb) could do away with rectal probes. In this prospective study, we compared Tb, rectal temperature (Tr) and pulmonary artery catheter temperature (Tpa) in pa-tients who underwent cardiac surgery. We also evaluated if urinary production affected Tb. Patients admitted after cardiac surgery with sensors in place for measurement of Tr, Tb and Tpa upon arrival at the ICU were included. Diuresis was recorded every hour. Data were collected until 24 h after admission or until ICU discharge. Nineteen consecutive patients (9 males; mean age 61 years) were evaluated. Over a median observation period of 17 hours 382 Tb, 333 Tr and 371 Tpa measurements were recorded. Linear correlations (R) between Tb and Tr, between Tb and Tpa and between Tr and Tpa were 0.95, 0.95 and 0.91 respectively (P < 0.001). Bland-Altman analysis demonstrated no relation between temperature and the (Tb-Tr) offset. No relation of diuresis with (Tb- Tr) or (Tb-Tpa) was observed. After cardiac surgery, bladder temperature performed as well as conven-tional rectal probes with no interference of diuresis on bladder temperature measurement. Thus, the use of bladder temperature probes may be preferable to rectal probes in patients after cardiac surgery