Objective To determine the median effective dose (EDs0) of etomidate inducing electroencephalogram (EEG) burst suppression (BS) in the patients with non-intracranial diseases.Methods American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients of both sexes,aged 18-64 yr,with body mass index of 19-27 kg/m2,scheduled for elective non-intracranial surgery,were enrolled in this study.ED50 of etomidate was determined by Dixon's up-and-down sequential method.Etomidate was intravenously injected for 30 s at an initial dose of 0.30 mg/kg.The BS ratio was recorded within 6 min following the end of injection.Each time ED50 increased/decreased in the next patient depending on whether or not BS occurred.The difference between the two successive doses was 0.05 mg/kg.Successful induction of BS was defined as BS ratio＞ 10％,lasting more than 1 min.Probit analysis was used to calculate the ED50 and 95％ confidence interval of etomidate inducing EEG BS in the patients with non-intracranial diseases.Results The ED50 of etomidate inducing EEG BS was 0.70 mg/kg,and the 95％ confidence interval was 0.65-0.81 mg/kg in the patients with non-intracranial diseases.Conclusion The ED50 of etomidate inducing EEG BS is 0.70 mg/kg in the patients with non-intracranial diseases.

Objective:To evaluate the lung protection of pressure-controlled ventilation volume guaranteed (PCV-VG) in elderly patients undergoing laparoscopic surgery in Trendelenburg position.Methods:Sixty patients of American Society of Anesthesiologists physical status Ⅰ-Ⅲ, aged 65-80 yr, with body mass index of 19-27 kg/m 2, scheduled for elective laparoscopic radical prostatectomy or laparoscopic radical cystectomy, were allocated into 2 groups ( n=30 each) by a random number table method: VCV group (group V) and PCV-VG group (group P). Tracheal intubation was performed after induction of anesthesia.The anesthesia machine was connected to perform mechanical ventilation with tidal volume of 7 ml/kg (corrected body weight), positive end-expiratory pressure at 5 cmH 2O, inspiratory/expiratory ratio 1∶2, fraction of inspired oxygen 50%, fresh gas flow at 2 L/min and respiratory rate 12-15 breaths/min in two groups.Recruitment maneuver was performed with a pressure of 30 cmH 2O, lasting for 30 s, starting from 5 min before the end of administration.The airway peak pressure (P peak), airway plateau pressure (P plat), driving pressure (DP), and dynamic lung compliance (Cdyn) were measured at 5 min after intubation (T 1), 5 min after changing position (T 2), 5, 30, 60, 90 and 120 min of pneumoperitoneum (T 3-7) and 5 min after restoring the supine position and after the end of pneumoperitoneum (T 8). Blood samples were collected from the radial artery for blood gas analysis at T 1, T 4 and T 6 and when modified Aldrete score reached 10 in postanesthesia care unit, and pH value, partial pressure of arterial oxygen (PaO 2), partial pressure of arterial carbon dioxide (PaCO 2), arterial oxygen saturation (SaO 2) and alveolar-arterial oxygen gradient (P A-aO 2) were recorded.Blood samples were collected from the radial artery before induction of anesthesia and at the end of surgery for determination of concentrations of Clara cell protein (CC-16), interleukin-6 (IL-6) and neutrophil elastase (NE) in serum by enzyme-linked immunosorbent assay.The development of pulmonary complications was recorded within 7 days after surgery. Results:Compared with group V, P peak was significantly decreased at T 1-8, P plat and DP were decreased at T 5-7, Cdyn was increased at T 2-7, P A-aO 2 was decreased at T 1, 4, 6, serum CC-16, IL-6 and NE concentrations were decreased at the end of surgery ( P<0.05), and no significant change was found in the incidence of pulmonary complications within 7 days after surgery in group P ( P>0.05). Conclusion:PCV-VG can produce lung protection to some extent in elderly patients undergoing laparoscopic surgery in Trendelenburg position.

Objective:To evaluate the effects of different subanesthetic doses of esketamine on lung injury in elderly patients undergoing robot-assisted radical prostatectomy.Methods:Ninety American Society of Anesthesiologists Physical Status classification Ⅱ or Ⅲ patients, aged 65-80 yr, with body mass index of 19-27 kg/m 2, scheduled for elective robot-assisted radical prostatectomy under general anesthesia, identified as having middle and high risk using the Assess Respiratory Risk in Surgical Patients in Catalonia, were divided into 3 groups ( n=30 each) using a random number table method: low-dose esketamine group (ES1 group), extremely low-dose esketamine group (ES2 group) and control group (C group). In ES1 group, esketamine was intravenously injected as a bolus of 0.2 mg/kg during anesthesia induction followed by an infusion of 0.125 mg·kg -1·h -1 until 30 min before the end of operation. In ES2 group, esketamine was intravenously injected as a bolus of 0.1 mg/kg during anesthesia induction followed by an infusion of 0.015 mg·kg -1·h -1 until 30 min before the end of operation. The equal volume of normal saline was given instead in C group. Radial artery blood samples were collected before anesthesia induction (T 0) and at the end of operation for determination of concentrations of Clara cell secretory protein (CC-16) and soluble form of advanced glycation end products receptor (sRAGE) in serum by enzyme-linked immunosorbent assay. The parameters of respiratory mechanics such as the driving pressure, dynamic lung compliance and mechanical power were recorded at 5 min after mechanical ventilation (T 1), and at 1 and 2 h after Trendelenburg position combined with pneumoperitoneum (T 2-3), and at 5 min before the end of operation (T 4). Blood samples were collected from the radial artery at T 0, T 1, T 3 and in the postanesthesia care unit for blood gas analysis, and the alveolar-arterial partial oxygen pressure difference and oxygenation index were recorded. The adverse reactions within 24 h after operation and the occurrence of postoperative pulmonary complications within 7 days after operation were recorded. Results:Compared with C group, the serum CC-16 and sRAGE concentrations were significantly decreased at the end of operation, the oxygenation index was increased and the alveolar-arterial partial oxygen pressure difference was decreased in the postanesthesia care unit, and the incidence of postoperative nausea reactions within 24 h after operation was decreased in ES1 and ES2 groups ( P<0.05 or 0.01). Compared with ES2 group, the serum CC-16 and sRAGE concentrations were significantly decreased at the end of operation in ES1 group ( P<0.05). There were no statistically significant differences in the driving pressure, dynamic lung compliance and mechanical power at T 1-4 and the incidence of postoperative pulmonary complications within 7 days after surgery among the three groups ( P>0.05). Conclusions:Esketamine given as a subanesthetic bolus of 0.2 mg/kg during anesthesia induction followed by an infusion of 0.125 mg·kg -1·h -1 can alleviate lung injury in elderly patients undergoing robot-assisted radical prostatectomy.

Objective To observe the effect of electroacupuncture(EA)on the expression of NKCC1,KCC2 and activation of microglia in spinal dorsal horn of paclitaxel(PTX)-induced neuropathic pain rats and its possible mechanism.Methods Male SD rats were randomly divided into the vehicle group(vehicle),the PTX group,the PTX+EA group and the PTX+sham EA group,with 12 rats in each group.The rat model of PTX-induced neuropathic pain was established by intraperitoneal injection of PTX.After modeling,EA was applied to"Zusanli"and"Yanglingquan"for 7 days in the PTX+EA group.Paw withdrawal threshold and paw withdrawal latency were tested at 2 days before and 1,3,5,7,14 and 21 days after PTX injection.Immunofluorescence and Western blot assay were used to detect expression levels of sodium-potassium-chloride cotransporter 1(NKCC1),potassium-chloride cotransporters 2(KCC2)and microglia markers-ionized calcium binding adapter molecule 1(Iba1)in spinal dorsal horn.Results Compared with the vehicle group,mechanical and thermal hyperalgesia of both hind feet were found in the PTX group,and the expression of NKCC1 and the number of activated microglia in dorsal horn tissue of spinal cord were increased.Compared with the PTX group,mechanical and thermal hyperalgesia were significantly improved in the PTX+EA group at day 14 and 21,and the expression levels of NKCC1 and Iba1 in dorsal horn tissue of spinal cord were decreased.There was no significant difference in KCC2 expression between the four groups.Conclusion Electroacupuncture can effectively relieve paclitaxol-induced neuropathic pain,which may be related to the inhibition of NKCC1 expression and microglia activation in spinal dorsal horn of rats.