The progress of light sedation for critically ill adult patients in intensive care unit / 中华危重病急救医学

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.

Effect of mild hypothermia on recovery from cisatracurium blockade during recovery from anesthesia / 中华麻醉学杂志

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%

Effect of dexmedetomidine on minimal induced dose of propofol and endotracheal intubation cardiovascular reaction / 中国综合临床

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.

Efficacy of nalmefene antagonizing postoperative respiratory depression induced by opioids:a multicenter,randomized,double-blind,positive drug-controlled study / 中华麻醉学杂志

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.

Analgesic efficacy of thoracic paravertebral block after lobectomy performed via video-assisted thoracoscope / 中华麻醉学杂志

Objective To evaluate the analgesic efficacy of thoracic paravertebral block (PVB) in patients after lobectomy performed via video-assisted thoracoscope (VAT) .Methods Fifty ASA Ⅰ or Ⅱ patients of both sexes aged 20-76 yr weighing 45-90 kg undergoing elective lobectomy via VAT were randomly divided into 2 groups (n = 25 each): patient-controlled intravenous analgesia (PCIA) group and thoracic PVB group. PVB was performed according to the method described by Jamieson et al and Richardson et al. Paravertebral catheter was placed at T7-8 after induction of anesthesia and tracheal intubation. A loading dose of 0.5% ropivacaine 20 ml was administered via PVB catheter at 30 min before the end of operation. PVB was then controlled by the patients with 0.2% ropivacaine (bolus dose 8.0 ml, lockout interval 30 min). In PCIA group a loading dose of sufentanil 0.1 μg/kg was given iv at 30 mln before the end of operation. Sufentanil 1.0 μg/ml was used. PCIA included a bolus of 2 ml with a 15 min lockout interval and background infusion 2 ml/h. Numeric rating scale (NRS) (0=no pain, 10 = most severe pain) was used to assess the intensity of pain. NRS score, MAP, HR and SpO2 were recorded before operation (T0 ,baseline), 30 min after withdrawal of chest tube (Ti) and at 24, 48 and 72 h after operation (T2, T3, T4). Forced vital capacity (FVC) and forced expiratory volume first second (FEV1.0) were measured and FVC/FEV1.0 ratio was calculated after chest tube was withdrawn. Blood cortisone and glucose concentrations were determined at To, T1 and T4. Requirement for rescue analgesics and side effects were recorded. Results There was no significant difference in MAP, HR, SpO2 and NRS at rest between the 2 groups.NRS at coughing and blood cortisone and glucose concentrations were significantly lower and the postoperative FEV1.0 was significantly higher in PVB group than in PCIA group. The requirement for rescue analgesics and side effects were comparable between the 2 groups. Conclusion Thoracic PVB can provide better postoperative analgesia with little side effects.

Accuracy of stroke volume variation in monitoring blood volume during one-lung ventilation in patients undergoing thoracoscopy operation / 中华麻醉学杂志

Objective To evaluate the accuracy of stroke volume variation (SVV) in monitoring blood volume during one-lung ventilation in patients undergoing thoracoscopy operation. Methods Twenty-two ASA Ⅰ or Ⅱ patients ( 12 male, 10 female) aged 18-60 yr undergoing thoracoscopy operation under general anesthesia were studied. Anesthesia was induced with midazolam, sufentanil, propofol and rocuronium and maintained with TCI of propofol and remifentanil and intermittent iv boluses of vecoronium. Robertshow double-lumen endobronchial tube was inserted. Correct position of the tube was verified by fiberoptic bronchoscopy. The patients were mechani40 mm Hg. Radial artery was cannulated and connected to FloTrac pressure transducer and Vigileo monitor. A loading dose of 6% HES 5 ml/kg was infused over 10 min. MAP, HR, CO and SVV were recorded before and at 3 min after loading dose. The change rate of SVV (SVV) and CI (△CI) were calculated. Increase in CI by 11% was considered effective volume expansion. The ROC curve for SVV in determining the volume expansion efficacy was plotted. The area under the curve for SVV and 95% confidence interval were calculated. Results (1) CO were significantly increased while SVV decreased after a loading dose of HES. (2) During two-lung ventilation 12 patients responded to the 6% HES loading dose.SVV correlated with△CI ( - 0.710, P ＜ 0.05). The volume expansion efficacy was determined by SVV 11.5 % (sensitivity = 82 %, specificity = 92 % ). The area under the curve for SVV and 95% confidance interval were 0.880 (0.580-0.987). (3) During one-lung ventilation 11 patients responded to the 6 % HES loading dose. SVV correlated with CI ( - 0.668 , P ＜ 0.05). The volume expansion efficacy was determined by SVV 9.5 % ( sensitivity = 77 %, specificity = 63 % ). The area under the curve for SVV and 95% confidance interval were 0.971 (0.917-1.024). Conclusion One-lung ventilation does not alter the ability of SVV in monitoring blood volume in patients undergoing thoracoscopy operation.

Effects of inhalation of different concentrations of sevoflurane on pulmonary inflammatory response in rats / 中华麻醉学杂志

Objective To investigate the effects of inhalation of different concentrations of sevoflurane on pulmonary inflammatory response in rats. Methods One hundred and twenty adult Wistar rats of both sexes weighing 200-250 g were randomly divided into 4 groups: Ⅰ control group breathing room air (group C, n = 12);Ⅱ oxygen group breathing 40% O2(group O, n = 36);Ⅲ and Ⅳ sevoflurane groups breathing 1.5% and 3.0% sevoflurane in 40% O2 respectively (group S1, S2, n = 36). Group Ⅱ was further divided into 3 subgroups according to the duration of 40% O2 inhalation 4 h, 8 h and 10 h. Group Ⅲ and Ⅳ were further divided into 3 subgroups ( n = 12 each) breathing sevoflurane for 4 h, 8 h and 8 h followed by 2 h O2 (40%) inhalation. The animals were sacrificed at the end of O2 or/and sevoflurane inhalation. Broncho-alveolar lavage was performed in 6 animals in each subgroup. The TNF-α concentration in broncho-alveolar lavage fluid was determined. The TNF-α mRNA expression and MPO activity in the lung tissue were measured in the other 6 animals in each subgroup. Results Inhalation of 1.5% or 3.0% sevoflurane for 4 or 8 h did not induce inflammatory response in the lung as compared with animals breathing room air or 40% O2 . Conclusion Exposure to sevoflurane does not induce pulmonary inflammatory response in rats breathing spontaneously.

Effect of epineural or intraneural injection of ropivacaine on acutely injured sciatic nerve in rats / 中华麻醉学杂志

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.

Midazolam-morphine combined with TCI of propofol for endobranchial ultrasound-guided transbronchial needle aspiration / 中华麻醉学杂志

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.

Pre-and intra-operative risk factors associated with delayed weaning from ventilator during early postoperative period in patients undergoing liver transplantation / 中华麻醉学杂志

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.

Accuracy of BIS value for monitoring depth of sevoflurane-nitrous oxide anesthesia in children / 中华麻醉学杂志

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.

Efficacy of centrally fixed eyeball for assessment of depth of sevoflurane anesthesia in premature infants undergoing outpatient fundus examination / 中华麻醉学杂志

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.

Effects of inhalation of isoflurane on plasma and pulmonary levels of IL-1β and IL-10 in rats / 中华麻醉学杂志

Objective To investigate the effects of inhalation of isoflurane (Iso) on pulmonary and systemic inflammatory response through the changes in the plasma and pulmonary levels of IL-1β and IL-10 in rats. Methods Thirty-two adult male Wistar rats were randomly divided into 4 groups (n=8 each): group control (group C), group Iso-4 h, group Iso-8 h and group R. Group C inhaled air only. Group Iso-4 h and Iso-8 h inhaled in 40% O2 + 1.5% Iso for 4 and 8 h respectively. Group R inhaled 40% O2 + 1.5% Iso for 8 h and then withdrew and only inhaled 40 % O2 for 2 h. Blood samples were taken from femoral artery for measurement of plasma concentrations of IL-1β and IL-10 by ELISA. Then the rots were sacrificed to collect bronchoalveolar lavage fluid (BALF) for measurement of IL-1β and IL-10 concentrations. The right lung tissues were obtained for determination of the expression of IL-1β mRNA and IL-10 mRNA by RT-PCR. Results The BALF concentration of IL-1β and IL-1β mRNA expression in lung tissues were significantly higher in group Iso-4 h, and the concentrations of plasma and BALF IL-1β and IL-10, and the expression of IL-1β mRNA and IL-10 mRNA in lung tissues were significantly higher in group Iso-8 h than in group C (P<0.05), but there were no significant differences in the concentrations of plasma and BALF IL-1β and IL-10 and expression of IL-1β mRNA and IL-10 mRNA in lung tissues between group R and group C (P>0.05). The plasma and BALF IL-10 concentrations and IL-10 mRNA expression in lung tissues were significantly higher in group Iso-8 h than in group Iso-4 h (P<0.05). The concentrations of plasma and BALF IL-1β and IL-10 and expression of IL-1β mRNA and IL-10 mRNA in lung tissues were significantly lower in group R than in group Iso-8 h (P<0.05). Conclusion Isollurane inhalation can induce transient pulmonary and systemic inflammatory response in rats.

The effect of portal vein bloodletting before reperfusion on homeostasis and cardlopuimonary function during orthotopic liver transplantation / 中华普通外科杂志

Objective To investigate the clinical implications of portal vein bloodletting immediately before reperfusion during orthotopic liver transplantation(OLT).Methods Thirty-two patients with end-stage liver diseases undergoing non veno-venous OLT were divided into bloodletting group (n=21)and control group(n=11).During anhepatic phase,we maintained mean arterial pressure ＞70 mm Hg,cardiac index＞2.5 L·min-1·m-2 by infusion,norepinephrine and dopamine.Blood samples were taken at the time when portal vein was clamped(T1),the time when portal vein was unclamped (T2),10 minutes after neohepatic phase(T3),neohepatic phase 30 minutes(T4)for electrolytes,blood gas and plasma inflammatory cytokines.Hemodynamic and ventilation parameters were also recorded.Results There was no significant difference in mortality(X2=1.12,P＞0.05)and arrhythmia incidence (X2=1.73,P＞0.05)between the two groups.Serum calcium,magnesium were both significantly lower than normal.After anhepatic phase,potassium,tumor necrosis factor alpha,interleukin-6 in radial artery didn't alter significantly;Bloodletting had no effect on lactic acid.There was no significant difference in hemodynamic and ventilation parameters among four time periods.Conclusion Bloodletting seemed to have no effect on changes of internal environment.

Pharmacokinetic/pharmacodynamic studies in anestheticdrug-drug interactions——a response surface model with remifentanil and sevoflurane for Chinese adult patients / 中国临床药理学与治疗学

AIM: To determine the interactions with response-surface modeling methodologies when sevoflurane (Sevo) and remifentanil (Remi) were administered simultaneously. METHODS: (1) Patients, Study design and drug delivery: Based on parallel slices design, sixty-five patients were randomly assigned to inhale a specific end-tidal concentration of sevoflurane (0.3% to 3.4%), with different level of remifentanil (0-10 ng/mL). The responses to laryngoscopy were observed for each given concentration pair. (2) Pharmacokinetic/pharmacodynamic analysis with response surface mode: The probability of no response (P) was assessed in the modeling process as below. P=(Us+Ur)r/[U50/I(Q)]r+(Us+Ur)r RESULTS AND DISCUSSION: NONMEM estimated average values (RSE%) of the model parameters for laryngoscopy of C50,Sevo, C50,remi, U50, r, Imax and Qmax are 1.71% (12.9), 12.4 ng/mL (19.0), 6.62 (10.6), 1.53 (8.76), 2.31 (8.23), 0.706 (2.46), respectively. The inter-individual variability (CV%) in parameter Imax and inter-occasion variability (S.D.) in this model are 12.7 and 0.0316, respectively. It is concluded that the response-surface modeling approach provided a novel method to study drug-drug interactions.

Evaluation of Target Controlled Infusion of Midazolam for Sedation During Combined Spinal and Epidural Anesthesia / 医学研究杂志

Objective To evaluate the performance of the target controlled infusion(TCI) system with midazolam during combined spinal and epidural anesthesia. Methods Twenty female patients scheduled for selective lower abdominal or pelvic surgery under combined spinal and epidural anesthesia were enrolled in this study. They use combined spinal and epidural anesthesia with target controlled infusion of midazolam sedation. Midazolam plasma concentration was set at 100ng/ml. Blood pressure,heart rate, pulse oxygen saturation were monitored during anesthesia and operation. We use BIS as a pharmacodynamic value of midazolam sedation. Blood samples were taken from radial arterial for analysis of plasma midazolam concentration during infusion. Midazolam plasma concentration were tested by high performance liquid chromatography. Results MDPE of target controlled infusion with midazolam with Burher parameters was 38.7%, MDAPE was 38.7%,and wobble is 24.9% in Chinese female patients. Conclusions Burher parameters of midazolam target controlled infusion system should be correct, then can be used for our country female patients conscious sedation accurately.

Performance evaluation of rocuronium target-controlled infusion system in geriatric patients / 中国微创外科杂志

Objective To determine the difference between the measured(Cm) and the target rocuronium plasma concentration(Cp) in geriatric patients given by target-controlled infusion(TCI) during laparoscopic rectectomy or colectomy,and to evaluate the performance of the rocuronium TCI system(Szenohradszkay model).Methods Twenty-four ASA I～II patients aged 65～81 years old received selective laparoscopic rectectomy or colectomy.After induction,all patients received rocuronium by TCI system.The beginning Cp was 1000 ng/ml,then increased to 1300,1600,1900,2200,and 2500 ng/ml,according to the neuromuscular transmission response.The endpoint of Cp was determined when the T1 was maintained at 5%～10%.Radial arterial blood samples were taken before anesthesia and before the adjustment of Cp each time,to determine the plasma concentration of rocuronium by using HPLC/MS.We used parameters of bias,precision,and wobble to evaluate the performance of the TCI system. Results The endpoint Cp(when the T1 was maintained at 5%～10%) was 1600 ng/ml in 2 patients,1900 ng/ml in 5 patients,2200 ng/ml in 9 patients,and 2500 ng/ml in 8 patients.The bias,precision,and wolbble of the rocuronium TCI system were 4.69%,14.93%,and 17.24%,respectively. Conclusions The rocuronium TCI system with Szenohradszkay pharmacokinetic model is clinically acceptable for Chinese geriatric patients.

Total hepatic ischemia-reperfusion-induced lung injury in rats and protective effects of melatonin / 北京大学学报(医学版)

Objective:To explore total hepatic ischemia-reperfusion(I/R)-induced lung injury in rats,its related mechanism and the protective effects of melatonin on lungs.Methods: This study was divided into 2 parts.In the first part,72 healthy male SD rats weighing 250-300 g were randomly divided into 2 groups: I/R group(ischemia-reperfusion,n=36) and sham-operation group(n=36).Total hepatic I/R was produced by occlusion of hepatic helium for 30 minutes,and the occlusion was then released for reperfusion.The animals were killed at 5 minutes prior to ischemia and 0 h,0.5 h,1 h,3 h and 6 h after reperfusion in sham-operation group and I/R group(n=6 at each time point),and the lung tissue was taken.Through comparisons of these two groups,we observed the dynamic changes of lung tissue after total hepatic I/R.In the second part,12 healthy male SD rats weighing 250-300 g were randomly divided into 2 groups: melatonin group(n=6) and vehicle group(n=6).Melatonin(0.5%,10 mg/kg)or vehicle of the same volume was injected via femoral vein 15 min before ischemia and 10 min before reperfusion,the animals were killed at 1 h after reperfusion,and the lung tissue was taken.Through comparisons of these two groups,we observed the effects of melatonin.Results:(1)Total hepatic I/R led to severe histological injury in lungs.Compared with those in sham-operation group,the MDA content and apoptotic index were increased,the SOD activity was decreased,the p-ERK/ERK ratio and PCNA-positive index were decreased respectively 0 h and 0.5 h after reperfusion,and then were increased gra-dually.Histological examination revealed that the alveolar architecture was destroyed with interstitial thickening and neutrophil infiltration in I/R group.Correlate analysis revealed that p-ERK/ERK ratio showed a positive correlation with PCNA-positive index(r=0.56,P

Effects of isoflurane on lung surfactant protein A in rats / 北京大学学报(医学版)

Objective:To examine the effects of different concentrations of Isoflurane on the level of surfactant protein A(SP-A) and the expression of SP-A mRNA in the lung of rats.Methods: Thirty-two male Wistar rats were randomly divided into 4 groups: control group received 40%(volume fraction) O_2 inhalation(40% O_2,n=8);0.7% isoflurane group(n=8),1.5% isoflurane group(n=8).They and 2.0% isoflurane group(n=8).They were treated with 40%O_2 with 0.7%,1.5% and 2.0% isoflurane respectively.In each group,the rats inhaled experimental gas for 8 hours,and then were put to death immediately.Morphological changes of type Ⅱ pneumocytes were observed by transmission electron microscopy.Surfactant protein content in broncho-alveolar lavage fluid(BALF) was measured with Western Blotting.The level of intracellular SP-A was examined with immunohistochemistry(IHC).To assess the relative levels of SP-A mRNA in lung tissue,reverse transcriptase-polymerase chain reaction(RT-PCR) was used with the co-amplification of the "housekeeping" gene GAPDH as internal control.Results: Morphological changes of type Ⅱ pneumocytes were distinct in 1.5% isoflurane and 2.0% isoflurane groups.Isoflurane,after three doses,significantly reduced the SP-A content in BALF.Control group,(437 112)?25 654;0.7%Isoflurane group,355 789?28 116;1.5%Isoflurane group,238 554?31 531;(2.0%) Isoflurane group,223 632?25 710(P

Pharmacodynamics of Rocuronium by Target-Controlled Infusion in Elderly and Adult Patients during Laparoscopy Operation / 中国微创外科杂志

Objective To investigate the pharmacodynamics of rocuronium by targeted-controlled infusion(TCI)during laparoscopy in elderly and adult patients.Methods A total of 31 patients undergoing selective laparoscopy operation from the Department of Gynecology and Department of General Surgery were divided into elderly group(aged 65-81 years,n=17)and adults group(aged 18-55 years,n=14).Under general anesthesia,rocuronium was infused intravenously using a TCI system.The upper limb without intravenous infusion was employed for TOF.The target plasma concentration(Cpt)was started from 1.0 ?g/ml,and then increased to 1.3,1.6,1.9,2.2,and 2.5 ?g/ml successively according to the neuromuscular response to the TOF stimulation.The endpoint of Cpt was determined when the T1 was blocked by 90%-95%.After terminating the infusion,the time to recovery of T1 to 25%,TOF ratio to 0.7,and recovery of index were recorded.T1 scales with each Cpt and the rates of rocuronium infusion were also recorded.Results T1 scales with each Cpt were significantly lower in the elderly patients than those in the adults(P