Which method for pulmonary artery temperature measurement is described as the most accurate?

• A. Tympanic
• B. Esophageal
• C. PA catheter
• D. Oral

Answer: (C)

Measuring core temperature most accurately requires sampling from central blood. A pulmonary artery catheter carries a thermistor at its tip that sits directly in the pulmonary artery, so the reading reflects the temperature of blood in the central circulation with minimal influence from ambient conditions or regional flow. This makes it the most accurate method for core temperature monitoring in many anesthesia and critical care settings.

Others can deviate more easily from true core temperature. Tympanic temperature is affected by ear canal conditions and ambient temperature; oral readings can be influenced by recent liquids, breathing patterns, and mouth conditions; esophageal temps track core temperature reasonably well but can be confounded by reflux, suctioning, or sedation effects. Because of direct measurement in central circulation, pulmonary artery temperature remains the gold-standard compared with the other sites.