What are the different sites at which temperature can be monitored?

What are the different sites at which temperature can be monitored?

Temperature may be monitored via the oral, rectal, esophageal, nasopharyngeal, and tympanic membrane sites. It can also be monitored via a pulmonary artery catheter (PAC) or a urinary bladder catheter. With the exception of the oral route, all other methods provide a generally accurate and reproducible measurement of the core temperature in the general surgical patient. However, in the patient undergoing hypothermic cardiopulmonary bypass, significant gradients can exist between core, blood, and peripheral temperatures. Blood temperature, as measured by the PAC, reflects the temperature of the blood coming from the heart-lung machine, with core temperature (esophageal, nasopharyngeal, tympanic) lagging somewhat behind, and envelope temperature (rectal) taking even more time to equilibrate during both cooling and rewarming. Bladder catheter measurements should reflect peripheral temperature, but with high urine flows they are more likely to closely reflect blood temperature.