Body Temperature Alteration And Preventing Convalescent Shivering During Anesthesia For Craniocerebral Surgery

Mild hypothermia is common during general anesthesia, because anesthetics inhibit hypothalarnic thermoregulatory center, interfering central thermoregulation. Hypothermia occurring in anesthesia, its convalescent shivering, and its injuries to the body have been well-noted,although lower body temperature is an effective protection of the brain in craniocerebral operation. Convalescent hypothermia is likely to induce shivering reaction, which in turninvestigate the shivering conditions in anesthetic ccnvalescence and the benefits from preventing shiveringMaterial and MethodsSixty patients (31 males, 29 females, aged 18-58 years) were selected tor crarnocerebral surgry, with ASA grading I^II and body mass index(BMI) <30%. All subjects were anesthetized at normal operating room temperature. We randomly assigned them to group W(n=30) and group C (n= 30). For the former, during anesthesia we served them intraoperatively with piokiothermic circulating-water blanket connected with a 3M piokilothermal water-box to warm their skin when aneurysm had been securely dosed with forceps. For the latter, we just conducted anesthetization without any more intervention (the control).Anesthesia Induction and MaintenanceAnesthetic procedures were identical for two groups. Arropine (0.0lmg/kg) was injected IM 30 minutes before anethetization Fentanyl(3#g/kg) propofol (2mg/kg), and Succinylcholone(1.5mgkg) were administered for anesthesia induction with tracheal catheter inserted We used Vecuronium (6⁸mg) for anesthesia maintenance, Ohmeda 7900 anesflietic machine for cortrolling ventilation, and simultaneously with Isoflurane as well as Nitrous OxideMonitoringWe monitored non-invasive Hood pressure, heart rate SpO2 end-expiratorylevel of isoflurane P_ETCO₂,core temperature (tympanic membrane temperature)mean skin temperature ((chest,fotrarm,thigh,leg),operating room temperatureDuring anestheic convalescence we monitored triceps activities in shivering reaction by printing electromyogram at a speed of lmm/s.ANihon Kohden4-lead physiological recoder was used with insertion of AB-621Gand Bioelectric Input Box.Follow-upPostoperative follow-up of headache, fever; and heart rate was noted, with patienf shospitalizations after operation also recordedResultsThe Incidence of Shivering Reaction and Body Temperature Alteration Shivering incidence in group W (none, 0/30) differed significantly from that in group C (40% 12/30)(p<0.01). The core temperature recovered to 36.48+ 0.36℃ in group W, whereas it decreased from 37.17?025 to 35.09?.59PC in group C. Additional data concerning mean skin temperature changes and its trend are shown in table2and figure 1 respectively.Intraoperative Hemodynamic RecordsWe did not find obvious difference during anesthexcthetization bstween two groups in blood pressure and heart rate (tabte 3), as well as end-expiratory level of is of lurane and MAC (table 4). Though the values cfP_EICO₂ in two groups were significantly different (p<0.05), the small difference (1.8) was of little chinical importance The volume of fluid infusior,blood loss and urinary output was notapparently different (table 5) between two groups. The patients required no more blood transfusion, except tot one case in group W received bank blood (800ml) and one in group C (600ml). The difference was not significant between two groups in age, BMI, and operatingroom temperature.Myoelectric ActivitiesEMG showed no alteration for group W, Whereas 5-7 Hz shivering waw appeared on EMG in 12 cases for group C win tonic shivering wave 4-5 cycle/min waxing-and-vvaning(figures2). Findings inpostopecative follow-up are shown in table6.DiscussionDecrease in body temperature during anesthetization is related to anesthetics venous and inhalant anesthetics (e.g. enflurane, isofluane, sevoflurane, and desflurane)influence thermoregulation in the body Isoflurane was beneficial topatients under craniocerebral operation in our trial Bs descendant inhibition of c...