Temperature monitoring during epidural anesthesia for cesarean delivery

Tympanic, rectal, and axillary temperatures were measured and compared in 12 ASA Physical Status I and II parturients during epidural anesthesia for cesarean delivery. Measurements were performed before (T0) and at 15 (T1), 30 (T2), 45 (T3), and 60 (T4) minutes after epidural anesthesia. At birth, rectal neonatal and maternal temperatures were measured. Before anesthesia, maternal tympanic and rectal temperatures were statistically not different but higher than axillary temperature (difference, 0.5 degrees C). During anesthesia, all three maternal temperatures decreased. There was no difference for the first 45 minutes between rectal and tympanic membrane temperatures and no difference between tympanic and axillary temperatures after 30 minutes. The difference between rectal and tympanic temperatures became significant at T4. During the same period, the difference between axillary and tympanic temperatures became nonsignificant at T3 and T4. At birth, both maternal and newborn rectal temperatures were similar at 36.0 +/- 0.2 degrees C. The relative hypothermia observed in the newborns at birth after regional anesthesia was well correlated with the decrease in maternal temperature. A decrease in tympanic temperature of 1.4 degrees C developed during the course of epidural anesthesia for cesarean delivery. This decrease was underestimated by the measurement of rectal and axillary temperatures.