Jugular bulb temperature compared with noninvasive temperatures and cerebral arteriovenous oxygen saturation differences during open heart surgery

Limited information is available about the correlation between cerebral tem perature and routine temperature measurements during cardiopulmonary bypass in infants. Nasopharyngeal, tympanic membrane and rectal temperatures were compared with jugular bulb temperature in ten infants operated on with mod erate or deep hypothermia. The cerebral arteriovenous saturation difference s were correlated with the temperatures at the four measurement sites. The jugular bulb and nasopharyngeal temperatures showed the most rapid response during cooling and rewarming. The tympanic temperature response varied in an unpredictable way. Rectal temperature, which was the target for rewarmin g, lagged behind during both cooling and rewarming. Overwarming at the end of cardiopulmonary bypass, seen as jugular bulb and nasopharyngeal temperat ures exceeding 38 degrees C, was common after deep hypothermia. A high corr elation was found between the cerebral arteriovenous oxygen saturation diff erences and the jugular bulb temperature (r= 0.81) and the nasopharyngeal a nd the tympanic temperature (r = 0.79), whereas the correlation with rectal temperature was weaker (0.66).