Comparison of the Effect of Remimazolam With Sevoflurane on Postanesthetic Shivering

Study Overview
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Brief Summary
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The incidence of postanesthetic shivering (PAS) after general anesthesia is affected by the anesthesia maintenance agents. This study compared the effect of remimazolam with sevoflurane on PAS in patients with laparoscopic gynecologic surgery under general anesthesia.

Detailed Description
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Inadvertent perioperative hypothermia and postanesthetic shivering (PAS) are common after anesthesia regardless of anesthesia methods. The incidence of perioperative hypothermia and PAS after general anesthesia has been reported to be 37.5 to 77.2% and 20 to 70%, respectively. Shivering begins when vasoconstriction, a major mechanism to prevent body heat loss, is insufficient. PAS is one of the most common discomforts in the recovery room after general anesthesia. Therefore, PAS is common in hypothermic patients. Volatile or intravenous anesthetics impair the autonomic thermoregulatory vasoconstriction which usually preserves core body temperature. However, benzodiazepines, such as midazolam, do not significantly impair thermoregulation control, even when used in combination with common opioid doses. Remimazolam, a novel benzodiazepine, has been reported for the thermoregulatory vasoconstriction threshold and onset time of vasoconstriction in terms of core body temperature in patients undergoing robotic-assisted and laparoscopic radical prostatectomy. It decreased the vasoconstriction threshold less than propofol, one of the intravenous anesthetics, and the onset of vasoconstriction was faster than propofol. Investigators hypothesized that remimazolam reduced the incidence of hypothermia compared to sevoflurane, one of the volatile anesthetics, and eventually lowered the frequency of PAS. Therefore, this study compared the effect of remimazolam with sevoflurane on PAS in patients with laparoscopic gynecologic surgery under general anesthesia.

Official Title
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Comparison of the Effect of Remimazolam With Sevoflurane on Postanesthetic Shivering in Patients Undergoing Laparoscopic Gynecologic Surgery Under General Anesthesia-prospective Observational Study.

Conditions
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Anesthesia; Hypothermia

Intervention / Treatment
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* Drug: Sevoflurane
* Drug: Remimazolam


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients aged between 19 and 65 y, with ASA physical status classes I or II Exclusion Criteria: Patients with history such as thyroid disease, cardiopulmonary disease, blood coagulation disorder, liver dysfunction, cranial nerve disease, alcohol or drug abuse, a known allergy to the study drug, and those who had core body temperature > 38°C or < 36.5°C, BMI > 30 kg.m-2 or febrile illness were excluded. Patients who underwent surgery for less than 60 min, and those who did not consent to this study

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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Female

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Group S<br>Anesthesia induction was achieved by continuous infusion of 6 mg/kg/h of remimazolam, and the maintenance of anesthesia was maintained at a BIS between 40 and 60. For the maintenance of anesthesia, the end-tidal concentration of 1 minimum alveolar concentration (MAC) sevoflurane was administered | Drug: Sevoflurane<br>* For the maintenance of anesthesia, the end-tidal concentration of 1 minimum alveolar concentration (MAC) sevoflurane and the concentration was adjusted by 1% stepwise titration<br>|
| Group R<br>Anesthesia induction was achieved by continuous infusion of 6 mg/kg/h of remimazolam, and the maintenance of anesthesia was maintained at a BIS between 40 and 60. For the maintenance of anesthesia, 1-2 mg/kg/h of remimazolam was continuously infused. | Drug: Remimazolam<br>* For the maintenance of anesthesia, 1-2 mg.kg-1.h-1 of remimazolam was continuously infused.<br>* Other names: Byfavo®;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The incidence of postanesthetic shivering (PAS) | In the recovery room, an attending anesthesiologist observed shivering. The severity of PAS was assessed with a bedside shivering assessment scale, which rated shivering as None (Grade 0): no shivering noted on palpation of the masseter, neck, or chest wall, Mild (Grade 1): shivering localized to the neck and/or thorax only, Moderate (Grade 2): shivering involved gross movement of the upper extremities (in addition to neck and thorax) and Severe (Grade 3): shivering involved gross movements of the trunk and upper and lower extremities | during staying in recovery room | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The severity of PAS | The severity of PAS was assessed with bedside shivering assessment scale, which rate shivering as None (Grade 0): no shivering noted on palpation of the masseter, neck, or chest wall, Mild (Grade 1): shivering localized to the neck and/or thorax only, Moderate (Grade 2): shivering involved gross movement of the upper extremities (in addition to neck and thorax) and Severe (Grade 3): shivering involved gross movements of the trunk and upper and lower extremities | during staying in recovery room | 
| Mean arterial pressure (MAP) | MAP was checked at pre-induction, and after induction, every 10 minutes until the end of surgery. | during general anesthesia | 
| Heart rate (HR) | HR was checked at pre-induction, and after induction, every 10 minutes until the end of surgery. | during general anesthesia | 
| Core body temperature | The patient's core body temperature was measured using an infrared tympanic thermometer and the highest temperature among the three measurements was measured before induction of anesthesia and in recovery room. After anesthesia induction, a nasopharyngeal temperature probe was inserted through the nostril to a depth of 9.5 to 10 cm at an appropriate location. | during general anesthesia | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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shivering, general anesthesia, laparoscopic surgery