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Objective To screen the risk factors for postoperative residual neuromuscular blockade (RNMB) in the patients undergoing thoracic surgery.Methods A total of 733 patients undergoing elective thoracic surgery with general anesthesia,without neuromuscular disease,skin temperature ≥32 ℃,were transferred to the postanesthesia care unit (PACU) after surgery and given synchronized intermittent mandatory ventilation.Neuromuscular blockade was monitored immediately after admission to the PACU,and the occurrence of postoperative RNMB was defined as a train of four (TOF) ratio ＜90％ at the time of extubation.The patients were divided into RNMB group and nonRNMB group according to whether or not postoperative RNMB occurred.Each parameter of baseline patient characteristics,complications,sites and methods of surgery,anesthesia time,requirement for muscle relaxants during surgery,TOF ratio on arrival to the PACU,requirement for muscle relaxant antagonists in the PACU,and extubation time were recorded.The risk factors of which P values were less than 0.05 would enter the multivariable logistic regression analysis to stratify the risk factors for postoperative RNMB.Results A total of 385 patients developed postoperative RNMB,and the incidence was 52.5％.The results of multivariate logistic regression analysis showed that complications such as diabetes,intraoperative application of two kinds of muscle relaxants,average intraoperative consumption of cisatracurium ≥ 0.14 mg · kg-1 · h-1,TOF ratio on arrival to the PACU ≤ 0.5,and extubation time ≤ 30 min were independent risk factors for postoperative RNMB (P＜0.05).Conclusion Complications such as diabetes,intraoperative application of two kinds of muscle relaxants,average intraoperative consumption of cisatracurium 0.14 mg · kg-1 · h-1,TOF ratio on arrival to the PACU ≤ 0.5,and extubation time ≤ 30 min are independent risk factors for postoperative RNMB in the patients undergoing thoracic surgery.
ABSTRACT
Objective To evaluate the effects of dantrolene pretreatment on diaphragmatic function in septic rats .Methods Thirty adult male Sprague-Dawley rats , weighing 200-220 g , aged 9-10 weeks , were randomized into 3 groups (n=10 each) using a random number table :sham operation group (group S) ,spesis group (group CLP) and dantrolene group (group D) .The animals were anesthetized with pentobarbital sodium . Dantrolene 6 mg/kg was injected intraperitoneally (in dimethyl sulfoxide 500 μl ) .Sepsis was induced by cecal ligation and puncture 1 h later in CLP and D groups .The left and right diaphragm was rapidly excised at 24 h after cecal ligation and puncture . The left diaphragm was used to detect the systolic function including the single stimulation twitch , dmax/dt , dmin/dt , maximal force of tetanic contraction , force-frequency curves , and fatigue index .Results Compared with group S ,the single twitch myopalmus ,dmax/dt ,dmin/dt ,maximum peak tension and fatigue index were significantly decreased in group CLP ,the single stimulation twitch ,dmax/dt ,dmin/dt and maximal force of tetanic contraction were decreased , fatigue index was increased in group D , and the force-frequency curve was shifted downward in CLP and D groups ( P<0.05 or 0.01) .Compared with group CLP ,the single stimulation twitch ,dmax/dt ,dmin/dt ,maximal force of tetanic contraction and fatigue index were significantly increased in group D ( P< 0.05 or 0.01 ) .Conclusion Dantrolene pretreatment can improve diaphragmatic function in septic rats .
ABSTRACT
Objective To evaluate the effect of long-term glucocorticoid administration on nondepolarizing muscle relaxants-induced neuromuscular blockade in rat diaphragma in vitro.Methods Forty adult male SpragueDawley rats,aged 8 weeks,weighing 180-220 g,were randomized into 2 groups (n =20 each):control group (group C) and dexamethasone group (group D).In group D,dexamethasone 0.6 mg/kg was injected intraperitoneally once a day for 14 consecutive days,while the equal volume of normal saline was injected instead of dexamethasone in group C.The left phrenic nerve-hemidiaphragm was removed at 24 h after the last injection to evaluate the effect of d-tubocurarine.Different concentrations (0-10 μmol/L) of d-tubocurarine were added.The d-tubocurarine concentration-effect curve was drawn.The half inhibitory concentration and 95 ％ confidence interval of d-tubocurarine were calculated.Right diaphragma was removed for determination of the expression of embryonic nicotinic acetylcholine receptor (nAChRγ) mRNA and adult nicotinic acetylcholine receptor (nAChRε) mRNA by RTPCR.Results Compared with group C,the concentration-effect curve was shifted to the right,the half inhibitory concentration was significantly increased,and the expression of nAChRγ mRNA and nAChRε mRNA was up-regulated in group D (P ＜ 0.05).Conclusion Long-term glucocorticoid administration can weaken nondepolarizing muscle relaxants-induced neuromuscular blockade in rat diaphragma in vitro,and up-regulation of nAChR mRNA expression may be involved in the mechanism.
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Objective To investigate the effect of forced-air warming system on the cellular immune function during radical esophagus cancer resection. Methods Thirty-six ASA Ⅰ or Ⅱ patients of both sexes, aged ≤ 64 yr, with body mass index ＜ 30 kg/m2 , scheduled for elective radical esophagus cancer resection, were randomized to 2 groups ( n = 18 each): normal temperature care group (group C) and forced-air wanning group (group T) . Anesthesia was induced with midazolam, sufentanil, propofol and vecuronium. The patients were tracheal intubated and mechanically ventilated. The patients were not warmed intraoperatively in group C. In group T, the patients were prewarmed for 20 min at 43℃, using forced-air warming system before induction and then kept warm until the end of operation. The nasopharyngeal temperature was measured at 0, 30, 60, 120 and 180 min after anesthesia induction and at the end of operation (T1-6 ) to reflect the body temperature. Venous blood samples were taken at T1,6 for analysis of T-lymphocyte subsets (CD3+ , CD4+ , CD8+ , CD4+ /CD8+ ) and NK cells (by flow cytometry) and determination of the plasma concentrations of noradrenaline and adrenaline (by ELISA) . Results Compared with T1 , the body temperature was significantly decreased at T2-6 in group C, and the percentage of CD4+ cells and CD4+ /CD8+ ratio were significantly decreased and the percentage of CD8+ and plasma concentrations of noradrenaline and adrenaline increased at T6 in both groups ( P ＜ 0.05). Compared with group C, the body temperature was significantly increased at T2-6, plasma concentrations of noradrenaline and adrenaline were significantly increased at T, , while the change rate of concentrations was significantly decreased in group T ( P ＜ 0.05) . ConclusionThe efficiency of forced-air warming system in maintaining perioperative normothermia is good and it reduces the stress response, but it exerts no influence on the cellular immune function in patients undergoing radical esophagus cancer resection.