We investigated the effects of i.v. prostaglandin E1 (PGE1) on intraoperative changes of core temperature and the incidence of postoperative shivering in neurosurgical patients undergoing deliberate mild hypothermia. Eighty-three patients were randomly assigned to one of three groups: patients in the control group did not receive PGE1, whereas patients in the PG20 group and PG50 group received PGE1 at a dose of 0.02 and 0.05 microg x kg(-1) x min(-1), respectively. The administration of PGE1 was started just after the induction of anesthesia and continued until the end of anesthesia. Anesthesia was maintained with nitrous oxide in oxygen, sevoflurane, and fentanyl. After the induction of anesthesia, patients were cooled using a water blanket and a convective device blanket. Tympanic membrane temperature was maintained at 34.5 degrees C. During surgical wound closure, patients were rewarmed. Intraoperative changes in tympanic membrane and skin temperatures and the incidence of postoperative shivering were compared among groups. Demographic and intraoperative variables were similar among groups. There were no significant differences in tympanic temperatures among groups at each point during the operation. Skin temperature 30 min after rewarming and just after tracheal extubation was significantly lower in the PG20 group than in the PG50 group. Postoperative shivering was more frequent in the PG20 group (43%) than in the control (13%) and PG50 (17%) groups. These results suggest that the intraoperative administration of PGE1 does not affect changes in core temperature during deliberate mild hypothermia and that PGE1 at a dose of 0.02 microg x kg(-1) x min(-1) may increase the occurrence of postoperative shivering.
Implications: Deliberate mild hypothermia has been proposed as a means of providing cerebral protection during neurosurgical procedures. Vasodilating drugs may be used during deliberate mild hypothermia to maintain peripheral circulation and to enhance the cooling and rewarming rate. In the present study, however, we found no benefit from i.v. prostaglandin E1 administration during deliberate mild hypothermia in neurosurgical patients.