Effect Of Dexmedetomidine Combined With Dezocine On Preventive Analgesic In Elderly Patients With Hypertension Undergoing Thoracoscopic Surgery

Objective:To evaluate the effects of dexmedetomidine combined with dezocine on preventive analgesic in elderly patients with hypertension undergoing thoracoscopic surgery.Methods:Eighty patients of both sexes,aged 65⁸0 yr,with body mass index of 18.5²3.9 kg/m²,of American Society of Anesthesiologists physical status Ⅱ or Ⅲ,scheduled for elective thoracoscopic lobectomy surgery under general anesthesia,were randomly divided into 4 groups according to random digits table:dexmedetomidine group（group DEX）、dezocine group（group DEZ）、dexmedetomidine+dezocine group（group DD）and control group（group C）.In group DEX,patients were infused with dexmedetomidine at 0.4μg·kg^-1·h^-11 intravenously from beginning of operation until sewing leather.In group DEZ,dezocine 0.1 mg·kg^-1was injected intravenously at 15 minutes before induction of anesthesia and at the point of sewing leather.In group DD,dezocine 0.1 mg·kg^-11 was injected intravenously at 15 minutes before induction of anesthesia,followed by continuous infusion of dexmedetomidine at 0.4μg·kg^-1·h^-11 until sewing leather and then dezocine 0.1 mg·kg^-1was injected intravenously.While the equal volume of normal saline was given instead in group C.Four groups of patients started pump PCIA in PACU.MAP and HR were recorded at 20 minutes before induction of anesthesia（T₁）,the point of sewing leather（T₂）,immediately after extubation（T₃）,5 minutes after extubation（T₄）and 30minutes（T₅）,venous blood samples were also collected for detemination of the plasma concentration of NE at the same time.At T₄、T₅、60 minutes after extubation（T₆）,Ramsay scores and the emergence agitation degree of patients were recorded.VAS scores were recorded at 1 hour after surgery（T₇）and 4 hours（T₈）、12 hours（T₉）、24 hours(T₁₀).As well as the PCIA times and analgesic volume used during postoperative analgesia 24 h were recorded.The postoperative adverse reactions of the patients were observed.Results:1 Comparison of hemodynamic changes and the plasma concentration of NE at different time points in four groups of patients:Compared with group C,MAP was decreased（P<0.05）and HR was lowered from T₃ to T₅（P<0.05）,as well as the plasma concentration of NE from T₂ to T₅ was decreased in groups DEX、DEZ（P<0.05）.Compared with group C,MAP was decreased（P<0.05）,HR was lowered（P<0.05）and the plasma concentration of NE was decreased in group DD from T₂ to T₅（P<0.05）.Compared with group DEX and group DEZ,MAP was significantly decreased（P<0.05）,HR was obvisously lowered（P<0.05）and the plasma concentration of NE was significantly decreased in group DD from T₂ to T₅（P<0.05）.2 Comparison of the restlessness in four groups of patients during the recovery period:Compared with group C,Ramsay scores at T₄^T₆ were increased（P<0.05）and the emergence agitation levels were decreased in groups DEX、DEZ and DD（P<0.05）.Compared with group DEX and group DEZ,Ramsay scores in group DD at T₄^T₆ were obviously increased（P<0.05）and the emergence agitation levels were decreased significantly（P<0.05）.3 Comparison of postoperative analgesia in four groups of patients:Compared with group C,VAS scores at T₇^T₁₀were decreased（P<0.05）,PCIA times and analgesic volume used during postoperative analgesia 24 h were lowered in groups DEX、DEZ、DD（P<0.05）.Compared with group DEX and group DEZ,VAS scores at T₇^T₁₀were obvisously decreased（P<0.05）,PCIA times and analgesic volume used during postoperative analgesia 24 h were significantly lowered in group DD（P<0.05）.4 Comparison of postoperative adverse reactions in four groups of patients:Compared with group C,the incidence of hypertension、tachycardia、nausea and vomiting were decreased in groups DEX、DEZ and DD（P<0.05）.Compared with group DEX and group DEZ,the incidence of hypertension、nausea and vomiting in group DD were significantly decreased（P<0.05）.Conclusions:Dexmedetomidine combined with dezocine in elderly patients with hypertension undergoing thoracoscopic surgery has a good preventive analgesic effect,which can relieve the stress reaction,decrease the emergence agitation and reduce the degree of postoperative pain.