The Comparison of Remimazolam With Propofol in Core Body Temperature

The Comparison of Remimazolam With Propofol in Core Body Temperature in Patients Undergoing Robotic-assisted (RARP) and Laparoscopic (LRP) Radical Prostatectomy

Core body temperature is normally tightly regulated to within a few tenths of a degree. The major thermoregulatory defences in humans are sweating, arteriovenous shunt vasoconstriction, and shivering. Inadvertent hypothermia often complicates prolonged surgery. In patients becoming sufficiently hypothermic, reemergence of thermoregulatory vasoconstriction usually prevents further core hypothermia. The extent to which anesthetics reduce the vasoconstriction threshold depends on the type of drug and its concentration.

When propofol induces anesthesia, blood pressure decreases due to vasodilation, which is due to direct action on vascular smooth muscle and vasodilation due to blockage of the sympathetic nervous system. This results in a redistribution of body temperature, resulting in hypothermia. The effects of remimazolam on the central nervous system, respiratory and cardiovascular system have been studied. Remimazolam, a new type of benzodiazepine drug acts on the GABA-A receptor and has the advantages of rapid induction, rapid recovery, stable hemodynamics, and mild respiratory inhibition. At present, there is little literature on its practice in intraoperative thermoregulation under general anesthesia. Investigators hypothesized that the type of anesthetic agents might affect thermoregulatory mechanisms such as the redistribution of body heat, cutaneous heat loss or inhibition of thermoregulatory vasoconstriction. Therefore, Investigators investigated to compare remimazolam with propofol in core body temperature, vasoconstriction threshold and times to onset of vasoconstriction(min)in patients given laparoscopic assisted vaginal hysterectormy.

Remimazolm and Remifentanil (RR group): anesthesia was induced with remimazolam 6 mg/kg/h by continuous intravenous (IV) infusion and with the effect-site concentration of remifentanil 4 ng/ml and until the loss of consciousness (LoC), followed by remimazolam 1-2 mg/kg/h and remifentanil 3 ng/ml until the end of surgery. Propofol and Remifentanil (PR group), anesthesia was induced with the effect-site concentration of propofol of 6.0 μg/ml and remifentanil 4 ng/ml, and until the loss of consciousness (LoC), followed by the effect-site concentration of propofol of 2-4 μg/ml and remifentanil 3 ng/ml until the end of surgery.

After the induction of general anesthesia, a nasopharyngeal temperature probe was inserted through the nasal cavity, and a 9.5- to 10.0-cm depth was set for optimal placement. The nasopharyngeal temperature was recorded every 10 min until the end of surgery

the tympanic membrane temperature at which the skin temperature gradient (between forearm and index finger tip) equaled 0 °C

Inclusion Criteria: ASA physical classification I-III, Patients who undergoing Robotic-assisted or laparoscopic (LRP) radical prostatectomy. Exclusion Criteria: Patients who have Medications or any implanted device that could affect cardiovascular function Patients who have a history with heat imbalance, thyroid diseases, dystautonomia, Raynaud's syndrome, uncontrolled diabetes mellitus, or hypertension.