The Effect Of Superior Laryngeal Nerve Block With Different Concentration Of Ropivacaine In Epiglottiectomy Under Ultro-sound Guided Suspension Laryngoscope

Objective:To investigate the effect of ropivacaine with different concentrations for ultrasound-guided superior laryngeal nerve block on epiglottic cystectomy under general anesthesia self-retaining laryngoscope,so as to provide reference for the selection of anesthesia methods for epiglottic cystectomy under laryngoscope in clinical practice.Methods:This is a prospective randomized controlled single-blind study.90 patients with epiglottic cysts in the Department of Otolaryngology,Huai’an First Hospital Affiliated to Nanjing Medical University from September 2019 to June 2020 were selected.The patients were fasted and fasted for 8 hours before anesthesia,and intramuscular injection of longtonin 0.5 mg 30 minutes before surgery.Non-invasive ECG monitoring and bispectral index monitoring were performed after every patient entered operating room.Group A directly implemented tracheal intubation after induction of general anesthesia.After the experimental group entered the room,the bilateral superior laryngeal nerve block was guided under ultrasound guidance.Group B used 0.5%ropivacaine hydrochloride,group C used 0.25%ropivacaine hydrochloride,and then were performed general anesthesia with endotracheal intubation.Induction of general anesthesia was followed by intravenous injection of midazolam 0.05mg/kg,propofol 2.5 mg/kg,remifentanil 2μg/mg,cis-atracurium 0.2mg/kg.When bispectral index value was less than 50,endotracheal tube was intubated and fixed properly,and breathing parameters were adjusted to control end-expiratory carbon dioxide between 35-45.Propofol 5-8 mg/kg/h and remifentanil 0.2μg/mg/min were pumped by intravenous inject for intravenous general anesthesia to maintain BIS about 50.then a suspension laryngoscope was inserted,the cyst was cut under the laryngoscope.The amount of propofol infusion was adjusted during the operation to maintain the BIS value between 40-60.The baseline data levels in the three groups were observed.And the indexes in the research were observed,including the heart rate（HR）and mean arterial pressure（MAP）after the patient enters the operating room（T₀）,when BIS value was maintained around 50 after general anaesthesia（T₁）,immediately after the successful implantation of laryngoscope（T₂）,when the BIS value came back around 50 by adjusting the infusion rate of propofol（T₃）,and when extubation after general anesthesia（T₄）,the infusion rate of propofol at T₁ and T₃,and the maximum fluctuation range of BIS value during the implantation of the laryngoscope,visual analogue scale（VAS）pain score at 0 h,6 h,12 h after extubation,incidence of postoperative complications such as dyspnea and dysphagia,patient satisfaction score of anesthesia and others.Results:1.Intraoperative hemodynamics:there was no significant difference in HR and MAP among the three groups at T₀,T1 and T₃（P>0.05）;HR and MAP in group A were higher than those in groups B and C at T₂ and T₄（P<0.05）,but there was no significant difference between groups B and C（P>0.05）.2.Dosage of general anesthesia:the infusion rate of propofol in group A was higher than that in group B and group C at T₁ and T₃（P<0.05）,but there was no significant difference between groups B and C（P>0.05）;the infusion rate of propofol at T₃ in three groups was higher than that in T₁（P<0.05）.3.The fluctuation range of BIS value during the implantation of laryngoscope:the maximum fluctuation of BIS in group B and group C was lower than that in group A（P<0.05）,but there was no significant difference between group B and group C（P>0.05）.4.Postoperative analgesia:VAS pain scores in group B and group C were lower than those in group A at 0 h,6 h and 12 h after extubation（P<0.05）,but there was no significant difference between groups B and C（P>0.05）.5.Postoperative complications:the incidence of dyspnea,dysphagia and other complications in group C was lower than that in group B（P<0.05）.6.Anesthesia satisfaction score in group C was higher than that in group A and B（P<0.05）;there was no significant difference between group A and group B（P>0.05）.Conclusion:total anesthesia combined with ultrasound-guided supraglottic nerve block using ropivacaine can provide better intraoperative circulatory stability and postoperative analgesia than total anesthesia alone,but the use of 0.5%ropivacaine will cause a series of complications,which is not desirable.Compared with performing general anesthesia alone and 0.5%ropivacaine,0.25%ropivacaine hydrochloride for nerve block satisfaction is higher and has better superiority.