Backward-upward-rightward pressure(BURP)maneuver can improve glottic view and increase the success rate of intubation when direct laryngoscopy is used to solve difficult endotracheal intuba-tion,but some studies believe that it can worsen glottic view.With the wide application of video-laryngosco-py,the clinical value of BURP technique has again aroused controversy.This article reviews the definition,method,basic principle of BURP maneuver,effect of the BURP maneuver to improve glottic view during the using laryngoscopy,in order to provide reference for the solution of difficult erdotracheal intubation.

The latest advance of sedation for critically ill adult patients in intensive care unit (ICU) was reviewed in order to provide certain clinical information for the ICU physicians about sedation. Guidelines, clinical research, Meta-analysis, and reviews in recent years were collected using electronic data base. Discussions included: ① the definition of light sedation, and its effects on clinical outcome, stress, sleep and delirium; ② light sedation strategies included: the target population, the target sedation strategy and daily sedation interruption, clinical assessment and monitoring of sedation, selection of sedative drugs, light sedation extenuation; ③ light sedation strategies and pain, agitation, delirium control bundles; ④ the problems and prospects of light sedation. Light sedation is the main principle of currently ICU sedation strategy in critically ill adult patients. Goal-directed light sedation should be considered as a routine therapy in most clinical situation, and its goal should be achieved as early as possible in the early stage of sedation. Routine use of benzodiazepines should be avoided, especially in patients with or at a risk of delirium. Prevention and treatment of agitation with a combination of non-pharmacologic or pharmacologic methods; ICU specification rules for pain, agitation and delirium prevention and treatment should be made. Light sedation is the main ICU sedation strategy in adult patients now, but must be individualized for each patient.

Objective To investigate the effect of dexmedetomidine on minimal induced dose of propofol and cardiovascular responses to tracheal intubation.Methods A double-blind randomized controlled trial was conducted.Sixty patients who underwent elective laparoscopic surgery were randomly divided into the dexmedetomidine group (treatment group) and control group.Patients in treatment group were given dexmedetomidine at dose of 0.1 μg/kg · min for 10 min before anesthesia induction,and then infused with 0.4 μg/kg · h until the end.Sodium chloride injection was infused at the same rate in control group.After 10 minutes from the start of dexmedetomidine or sodium chloride injection,propofol was infused by 0.4 mg/kg · min.The dosage of propofol used was recorded when eyelash reflex disappearing,and BIS value in 40 to 60.Propofol was infusion at the same rate,and laryngoscope was incubated at 2 minutes after fentanyl and rocuronium were given.The alertness/sedation (OAA/S scores),mean arterial pressure (MAP),heart rate,pluse oxygen saturation (SpO2) and BIS values were recorded at baseline (before dexmedetomidine or sodium chloride injection infusion),5 and 10 minutes after dexmedetomidine or sodium chloride injection infusion,at the time of eyelash reflex disappearing,before endotracheal intubation,placing the laryngoscope,1,3 and 5 min after intubation.Results OAA/S scores and BIS values in the treatment group were significantly lower than that of control group at 5 minutes and 10 minutes after the dexmedetomidine or sodium chloride injection infusion(P ＜0.05).MAP in treatment group was higher than that of control group at the time of eyelash reflex disappearing,before endotracheal intubation,placing the laryngoscope,1,3 and 5 minutes after intubation (P ＜0.05).Heart rate in treatment group was lower than that of control group at 5 and 10 minutes after dexmedetomidine or sodium chloride injection infusion and before the endotracheal intubation(P ＜ 0.05).There was no significant difference in terms of SpO2 between two groups (P ＞ 0.05).When patients consciousness disappeared and BIS values were in 40-60,the minimum induced dose of propofol was (88.00 ± 25.91) mg in treatment group and (117.33 ± 25.45) mg in control group.The dosage of propofol treatment group was obviously less than control group (t =4.423,P ＜ 0.05).Conclusion Dexmedetomidine reduces the minimum induced dose of propofol while maintaining more stable hemodynamic changes during anesthesia induction.However,there has no obvious inhibition effect on cardiovascular response to tracheal intubation.

Objective To evaluate the effect of mild hypothermia on the recovery from cisatracurium blockade during the recovery from anesthesia in patients .Methods Thirty ASA physical status Ⅰ or Ⅱ patients , aged 18-64 yr , with body mass index 18-25 kg/m2 , scheduled for elective abdominal surgery under general anesthesia ,were enrolled in the study .The patients were divided into 2 groups according to the body temperature recorded when cisatracurium infusion was stopped at the end of surgery .The body temperature 36.0-36.9 ℃served as normothermia group (group N , n=14 ) and 34.0-35.9 ℃ served as mild hypothermia group (group H , n= 16 ) . The body temperature was measured by a thermocouple placed in the nasopharynx . Neuromuscular function was monitored by measuring the evoked mechanical response of the adductor pollicis muscle to supramaximal train-of-four (TOF) stimulation (frequency 2 Hz ,wave length 0.2 ms ,intensity 50 mA ,interval 15 s) of the ulnar nerve at the wrist using TOF-Watch SX? .Cisatracurium was intravenously infused at 1-3μg·kg-1 ·min-1 during surgery to maintain neuromuscular block with 1%

Objective To evaluate the efficacy of nalmefene antagonizing postoperative respiratory depression induced by opioids.Methods Two hundred and forty ASA Ⅰ orⅡpatients aged 18-64 yr with body weight fluctuating within 20% of the standard body weight were included in this multicenter,randomized,double-blind,positive drug-controlled study.Anesthesia was induced with etomidate 0.3 mg/kg and TCI of sufentanil(effect-site concentration 0.4.ng/ml).Tracheal intubation was facilitated with vecuronium 0.1 mg/kg or rocuronium 0.6mg/kg.The patients were mechanically ventilated.PETCO2 was maintained at 35-45 mm Hg.Anesthesia was maintained with sevoflurane+ sufentanil TCI(Ce=0.1-0.4 ng/ml).Patients undergoing neurosurgery and liver or kidney operation were excluded.The operation time was within 3 h.The residual effects of muscle relaxants were reversed after operation.The patients were randomly divided into 2 groups(n=120 each):group Ⅰneloxone andgroup Ⅱ nalmefene.Naloxone 0.1 mg or nalmefene 0.25 μg/kg was injected iv over 30 s and was repeated 5 min later if necessary until the respiratory rate＞10 bpm,PETCO2＜45 mm Hg and apnea time＜15 s.The total amount of naloxone was≤0.4 mg while that of nalmefene≤1 μg/kg.BP,HR,SpO2,PETCO2,respiratory rate and apnea time were recorded immediately before and at 2 and 5 min after haloxone/nalmefene administration and then every 5 min until 5 min after extubation.The recovery of spontaneous breathing within 30 min after naloxone/nalmefene administration,extubation time and Ramsay sedation score at 5 min after extubation were recorded.The patients were also observed for adverse reactions.Results Spontaneous breathing recovered within 30 min after naloxone/nalmefene administration in all patients in both groups.The extubation time was significantly shorter in nalmefene group than in naloxone group.There was no significant difference in Ramsay sedation score,BP,HR,SpO2 and incidence of adverse reactions between the 2 groups.Conclusion Nalmefene is better than naloxone in antagonizing opioid-induced postoperative respiratory depression.

Objective To investigate the efficacy of centrally fixed eyeball for assessment of the depth of anesthesia in premature infants undergoing outpatient fundus examination. Methods Fifty eight premature infants undergoing examination of fundus of eyes were enrolled in this study. Their gestational age (from the first day of last menstruation period to birth) + after birth age (from birth to the day when examination of fundus of eyes was performed) = 44-64 weeks. The patients were randomly divided into 2 groups: Ⅰ group body movement (group M, n = 27) and Ⅱ group centrally fixed eyeball (group E, n = 31). Anesthesia was induced and maintained with isoflurane inhalation. The patients were breathing spontaneously. The eyelids were kept open with speculum after induction of anesthesia. The EC50 of sevoflurane concentration which could inhibit body movement or make eyeballs centrally fixed was determined by up-and-down sequential experiment. The initial isoflurane concentration was 3% in both groups. Each time the isoflurane concentration was increased/decreased by 0.5 %. 95 % confidence interval (CI) was calculated. The lowest SpO2, respiratory rate and coughing during maintenance of anesthesia were recorded. Results The EC50 of sevoflurane (95% CI) was 2.9% (2.2%-3.6%) in group M and 3.4%(2.6%-4.6%) in group E. Examination was successfully completed in all patients. No respiratory depression and coughing occurred during examination and no vomiting and coughing were observed during feeding at 1 h after recovery from anesthesia. No body movement occurred in 15 patients whose eyeballs were centrally fixed in group E. Conclusion Centrally fixed eyeball can be used as sign of appropriate depth of anesthesia for fundus examination in premature infants.

Objective To evaluate the accuracy of BIS value for monitoring the depth of sevoflurane-nitrous oxide in children. Methods Seventy-two ASA Ⅰ or Ⅱ children aged 1-14 yr undergoing abdominal surgery were randomly assigned into 3 groups ( n = 24 each) :sevoflurane group (group S), sevoflurane + 30% N2O group (group SN1 )and sevoflurane + 60% N2O (group SN2 ). Anesthesia was induced with atropine, lidocaine, propofol, rocuronium and remifentanil. After tracheal intubation, the patients were mechanically ventilated. PETCO2 was maintained at 35-45 mm Hg. Anesthesia was maintained with 2.5% sevoflurane combined with 0, 30% and 60% nitrous oxide in group S, SN1 and SN2 respectively. The end-tidal sevoflurane concentration (CETSev) was maintained at 2.5%, 2.0% and 1.5%. Each CETSev was maintained for at least 10 min after the begining of the surgery. Then the CETSev was modified to maintain BIS value at 40-60. BIS value was recorded before anesthesia induction and each stable CETSev. CETSev was recorded at maintaining BIS value of 40-60 for at least 20 min ( C50 ).Results BIS value and C50 were significantly lower in group SN2 than in group S and SN1 ( P ＜ 0.05), while no significant difference was found between group S and SN1 ( P ＞ 0.05). BIS value was negatively correlated with CETSev in all 3 groups (r = -0.736, -0.817, -0.729, P ＜ 0.01).There was no significant difference in the correlation coefficients among the 3 groups ( P ＞ 0.05 ). Conclusion BIS value can accurately reflect the depth of sevoflurane-nitrous oxide anesthesia in children.

Objective To evaluate the pre- and intra-operative risk factors associated with delayed weaning from ventilator during the early postoperative period in patients undergoing liver transplantation.Methods Two hundred and twelve patients (152 male, 60 female) aged 22-69 yr undergoing liver transplantation from Sept 2004to Aug 2006 were enrolled in this study and were divided into 2 groups according to the time when the patients were weaned from ventilator: normal weaning group (Group A, the patients weaned from ventilator within 24 h after operation) and delayed weaning group (Group B, the patients weaned from ventilator more than 24 h after operation). Routine anesthesia wes performed. Blood and blood products were transfused according to the guidelines for blood transfusion to maintain the mean arterial pressure (MAP)≥60 mm Hg during operation. Sixteen preoperative variables (age＞64 yr, gender, BMI ≥ 30kg/m2, PaO2＜75 mm Hg,pleural effusion, a history of asthma, smoking, drinking alcohol, coronary artery disease, diabetes mellitus, encephalopathy＞grade 3, spontaneous bacterial peritonitis, preoperative MELD score, serum albumin, ascites≥20 ml/kg and moderate hepatopulmonary hypertension) and 7 intraoperative variables (duration of operation, duration of anhepatic stage, transfusions of RBC,fresh frozen plasma (FFP), crystalloid and colloid, and urine output＜ 1 ml·kg-1·h-1) were recorded and compared between the two groups.Results There were significant differences in 9 preoperative variables (age ＞ 64 yr, PaO2＜75 mm Hg, pleural effusion,encephalopathy＞grade 3, spontaneous bacterial peritonitis, preoperative MELD score, serum albumin, ascites≥20 ml/kg and moderate hepato-pulmonary hypertension) and 5 intraoperative variables (transfusions of RBC, FFP, crystalloid and colloid, and urine output＜1 mi·kg-1·h-1) between the two groups (P＜0.05 or 0.01). And logistic regression analysis showed that 5preoperative variables (age＞64 yr, PaO2＜75 mm Hg, encephalopathy ＞ grade 3, preoperative MELD score, and moderate hepato-pulmonary hypertension) and 2 intraoperative variables (transfusion of RBC and urine output＜1 ml·kg-1·h-1) were confirmed to be associated with delayed weaning from ventilator.Conclusion Such variables es age ＞ 64 yr, preoperative PaO2 ＜ 75 mm Hg, encephalopathy ＞ grade 3, preoperative MELD score, moderate hepato-pulmonary hypertension, transfusion of RBC during operation and urine output ＜ 1 ml· kg-1 · h-1 are associated with delayed weaning from ventilator during early postoperative period after liver transplantation.

Objective To evaluate the effectiveness of midazolam and morphine combined with TCI of propofol for endobronchial ultrasound-guided transbronchial needle aspiration ( EBUS-TBNA ). Methods Forty ASA Ⅰ or Ⅱ patients undergoing elective EBUS-TBNA were randomly divided into 2 groups according to the plasma concentration (Cp) of TCI of propofol (n=20 each): group Ⅰ Cp = 3 μg/ml (group P1) and group Ⅱ Cp = 4 μg/ml (group P2 ). Midazolam 0.03 mg/kg and morphine 0.05 mg/kg were administered iv followed by topical anesthesia of laryngopharynx with 4% hdocaine. TCI of propofol was started at 5 min before surgery. The patients kept spontaneous breathing during operation. MAP, HR and SpO2 were continuously monitored and recorded before anesthesia (baseline) and at 30 min after beginning of surgery and emergence from anesthesia. Arterial blood gas analysis was performed at 30 min after beginning of surgery and PETCO2 was measured at the end of surgery. The amount of 4% lidocaine used for topical anesthesia, the adverse reactions and the level of patient's satisfaction were recorded. Results PaO2 and pH value were significantly lower while PaCO2 and PET CO2 higher in group P2 than in group P1. There was no significant difference in the emergence time, the amount of 4% lidocaine used,the adverse reactions and the level of patient's satisfaction between the 2 groups. Conclusion TCI of propofol at Cp of 3 μg/ml can provide satisfactory anesthesia for EBUS-TBNA with less respiratory depression and more rapid emergence than that at Cp of 4 μg/ml.

Objective To investigate the effects of 1% ropivacaine injected epineurally or intraneurally on the recovery of sciatic nerve from acute injury in rats. Methods Seventy-two healthy male Wistar rats weighing 220-250 g were xandomly assigned into 4 groups ( n = 18 each): group Ⅰ epineural injection of normal saline(NS)(group C1); group Ⅱ intraneural injection of NS (group C2); group Ⅲ epineural injection of 1% ropivacaine (group Epi-R) and group Ⅳ intraneural injection of 1% ropivacaine (group Intra-R). The animals were anesthetized with intraperitoneal 3% pentobarbital 60 mg/kg. The sciatic nerve was exposed and crushed with blood vessel clamp for 2 min. NS or 1% ropivacaine 0.2 ml was injected epineurally or intraneurally after release of the clamp.Sciatic nerve function was measured and sciatic nerve function index (SFI) was calculated at day 1, 3, 7, 14, 21and 28 after operation. Six animals in each group were anesthetized on the 14th and 28th day after operation and the nerve conduction velocity (NCV) of the sciatic nerve was measured. The sciatic nerve was then removed for histologic examination. Results There was no significant difference in SFI and NCV at all time points among group C1 , C2 and Epi-R. SFI was almost normal on the 28th day after operation in the 3 groups. The NCV was significantly slower at day 14 and 28 after operation in intra-R group than in the other 3 groups. Conclusion Intra-neural injection of ropivacaine can significantly delay the recovery of sciatic nerve from acute injury.