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Objective:To determine the oxygen concentration threshold for explosion induced by high-frequency electric knife or argon knife at different energies.Methods:① In vivo experiment The smooth muscle tissue or adipose-rich tissue in 10 pairs of isolated porcine lungs and trachea was electrocauterized at 30 and 50 W with high-frequency electroknife or argon knife at different oxygen concentrations.The initial oxygen concentration was 20%, the oxygen concentration was gradually increased in increments of 5% until the oxygen concentration reached 80%.Each sample was electrocauterized 10 times at each concentration, and the number of explosion was recorded.As long as one explosion occurred, it could be considered that the concentration could induce explosion, and the minimum oxygen concentration inducing explosion was considered as the threshold.② Measurement of oxygen concentration in the airway of patients received bronchoscopic intervention Thirty patients scheduled for elective bronchoscopy with cryotherapy were selected, the oxygen concentration inhaled was reduced from 100% until 50% in decrements of 10%, and the oxygen concentration in airway was measured with the AIRVO 2 transnasal high-flow oxygen inhalation device.ICC consistency analysis was performed between the oxygen concentration in airway and oxygen concentration inhaled. Results:In adipose-rich tissues, the threshold of the oxygen concentration for explosion was 70% at 30 W and 65% at 50 W when using the high-frequency electric knife; the threshold of the oxygen concentration for explosion was 35% at 30 W and 30% at 50 W when using the high-frequency argon knife.In smooth muscle tissues, no explosion occurred at each oxygen concentration when using the high-frequency electric knife and argon knife at 30 or 50 W, and the threshold value was above 80%.There was moderate consistency (ICC value 0.722, 95% CI 0.537-0.850, P<0.001) between the oxygen concentration in airway and oxygen concentration inhaled. Conclusions:In smooth muscle tissues, explosion is not easy to occur at oxygen concentrations below 80% when using the high-frequency electric knife or argon knife.In adipose-rich tissues, explosion is not easy to occur at oxygen concentrations less than 70% at 30 W and at oxygen concentrations less than 65% at 50 W when using the high-frequency electric knife; explosion is not easy to occur at oxygen concentrations less than 35% at 30 W and at oxygen concentrations less than 30% at 50 W when using the high-frequency argon knife.The threshold of oxygen concentrations in airway can be determined using the oxygen concentration inhaled.
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Objective:To evaluate the effect of erector spinae plane (ESP) block combined with general anesthesia on early postoperative cognitive function in elderly patients undergoing thoracoscopic radical resection of lung cancer.Methods:Sixty patients of both sexes, aged ≥65 yr, with body mass index< 30 kg/m 2, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ, scheduled for single-port thoracoscopic radical resection of lung cancer, were divided into 2 groups ( n=30 each) using a random number table method: ESP block plus general anesthesia group (group ESP+ GA) and general anesthesia group (group GA). Ultrasound-guided ESP was performed at T 4 before induction of general anesthesia in group ESP+ GA.The success of the nerve block was determined by pin-prick test at 20 min after nerve block, and then anesthesia was induced.Anesthesia was maintained with propofol plus remifentanil in the two groups.Patient-controlled intravenous analgesia was performed.Venous blood samples were collected at 1 day before operation and 1, 2 and 3 days after operation for determination of plasma S100β protein and neuron-specific enolase (NSE) concentrations by enzyme-linked immunosorbent assay.At 1 day before operation and 3, 5, and 7 days after operation, the early cognitive function was assessed using the Mini-Mental State Examination (MMSE), and the occurrence of postoperative cognitive dysfunction within 7 days after operation was recorded.The intraoperative consumption of propofol, remifentanil and sufentanil was recorded.The occurrence of complications related to ESP block was recorded. Results:Compared with group GA, the consumption of propofol, remifentanil, and sufentanil was significantly reduced, the serum S100β protein concentration and Mini-Mental State Examination score were decreased at 1 and 3 days after operation, serum NSE concentrations were decreased at 1, 3 and 5 days after operation, and the incidence of postoperative cognitive dysfunction was decreased in group ESP+ GA ( P<0.05). ESP block was successful, and no vascular and nerve damage was found in group ESP+ GA. Conclusion:ESP block combined with general anesthesia can improve the early cognitive function after thoracoscopic radical resection of lung cancer in elderly patients.
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Objective:To evaluate the efficacy of constant flow oxygen supply via laryngeal mask airway combined with a thin tube at the distal end of airway stenosis for intraoperative ventilation in the patients with severe tracheal stenosis undergoing bronchoscopy. Methods:Forty patients of either sex, aged 18-70 yr, scheduled for comprehensive interventional therapy with tracheoscope for severe tracheal stenosis, were allocated into 2 groups ( n=20 each) by a random number table method: test group and control group.After routine anesthesia induction, intermittent positive pressure ventilation was supplied via a laryngeal mask airway linked to four-way connector and anesthesia machine.In test group, a 6Fr suction tube was inserted through the four-way connector and placed at the distal end of the stenosis, with 1 L/min flow oxygen supply.Before ventilation with the thin tube (T 0), at 30 min after start of mechanical ventilation (T 1), and at the end of operation (T 2), SpO 2, P ETCO 2, mean airway pressure (Pmean), and minute ventilation (MV) were recorded, monitoring of lung ventilation was implemented using electrical impedance tomography, and the area percentages of the centre of ventilation (CoV), dependent silent spaces (DSS), and non-dependent silent spaces (NSS) were recorded.Blood gas analysis was performed at T 1 to record pH value, PaO 2 and PaCO 2.Hypoxemia was recorded during ventilation. Results:Compared with control group, MV, Pmean and area percentage of NSS were significantly increased and area percentage of DSS was decreased at T 1, 2, P ETCO 2 was decreased and SpO 2 and area percentage of CoV were increased at T 1, pH value and PaO 2 were increased, and PaCO 2 and the incidence of hypoxemia were decreased in test group ( P<0.05). Conclusion:Combination of laryngeal mask airway and a thin tube at the distal end of airway stenosis for constant flow oxygen supply can improve the ventilation efficacy by increasing the oxygen concentration at the distal end of the stenosis and by reopening the collapsed lung tissue at the distal end during interventional therapy with tracheoscope in the patients with severe tracheal stenosis.
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Objective:To evaluate the effect of preoperative sleep deprivation on the intestinal microflora of immunosuppressed mice after operation.Methods:Seventy-two SPF healthy adult male C57BL/6J mice, aged 8-10 weeks, weighing 23-25 g, were divided into 5 groups using a random number table method: operation group (group O, n=18), preoperative sleep deprivation group (group SR, n=18), pseudo germ-free mice orally treated with normal saline group (group GF+ V, n=12), pseudo germ-free mice that received fecal bacteria transplants from mice in group O group (group GF+ C, n=12), and pseudo germ-free mice that received fecal bacteria transplants from mice in group SR group (group GF+ SR, n=12). In group O and group SR, mice were subjected to sleep deprivation for 20 h every day for 7 consecutive days starting from 7 days before intraperitoneal exploration and partial liver lobectomy.Broad-spectrum antibiotics dissolved in drinking water were given ad libitum to C57BL/6 mice for 14 consecutive days starting from 2 weeks before operation to establish the pseudo germ-free mice model.Pseudo germ-free mice were gavaged with normal saline or fecal suspension (200 μl) obtained from mice at 24 h after surgery in group O and group SR.The fecal samples were collected at 24 h after operation for 16S rRNA gene sequence analysis.The longitudinal diameter and weight of the spleen were measured at 24 h after operation or fecal microbiota transplantation (FMT). CD4 + T cells, CD8 + T cells and regulatory T cells (Treg cells) were detected by flow cytometry. Results:Compared with group O, the Simpson diversity index of intestinal microflora was significantly decreased, the number of CD4+ T cells and CD8+ T cells in blood was decreased, the percentage of Treg cells was increased, and the longitudinal diameter and weight of the spleen were decreased in group SR, and the numbers of CD4 + and CD8 + cells in blood were significantly decreased, the percentage of Treg cells in blood was increased, and the longitudinal diameter and weight of the spleen were decreased in group GF+ V ( P<0.05). Compared with group GF+ V, the number of CD4 + T cells and CD8 + T cells in the blood was significantly increased, the percentage of Treg cells was decreased, and the longitudinal diameter and weight of the spleen were increased in group GF+ O ( P<0.05). Compared with group GF+ O, the number of CD4+ T cells and CD8+ T cells in blood was significantly decreased, the percentage of Treg cells was increased, and the longitudinal diameter and weight of the spleen were decreased in group GF+ SR ( P<0.05). Conclusion:The mechanism by which preoperative sleep deprivation accentuates postoperative immunosuppression is related to the intestinal microflora disorder in mice.
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Objective To evaluate the efficacy of endotracheal tube (ETT) with injecting medicine for continuous airway topical anesthesia in inhibiting responses to an indwelling ETT after operation in the patients undergoing maxillofacial surgery. Methods Sixty patients of both sexes, aged 18-64 yr, weig-hing 45-75 kg, of American Society of Anesthesiologists physical status Ⅰor Ⅱ, scheduled for elective maxillofacial surgery under general anesthesia, were divided to control group ( group C) and ETT with in-jecting medicine for continuous airway topical anesthesia group (group E) by a random number table meth-od, with 30 patents in each group. ETT was indwelled until the patients were admitted to intensive care unit (ICU) after the end of surgery, midazolam 0. 02-0. 03 mg∕kg was intravenously injected, and sufentanil was intravenously infused at a rate of 0. 02-0. 10 μg·kg-1·h-1for sedation. In group E, 2% lidocaine 2 ml was injected through the ETT with injecting medicine every 2 h to perform airway topical anesthesia. The equal volume of normal saline was injected through the ETT with injecting medicine every 2 h to maintain the Ramsay sedation score ≥2 in group C. The occurrence of hypertension, tachycardia and bucking and seda-tive requirements were recorded within 24 h after admission to ICU. The concentrations of norepinephrine and methoxyepinephrine in urine were determined by enzyme-linked immunosorbent assay at 24 h after ad- mission to ICU. Results Compared with group C, the frequency of hypertension, tachycardia and bucking were significantly decreased, the consumption of midazolam and sufentanil was reduced, and the concentra-tions of norepinephrine and methoxyepinephrine in urine were decreased in group E (P＜0. 05). Conclusion ETT with injecting medicine can markedly inhibit responses to an indwelling ETT after operation when used for continuous airway topical anesthesia in the patients undergoing maxillofacial surgery.
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Objective To evaluate the efficacy of four-way pipe fitting with laryngeal mask airway (LMA) for airway management during tracheal stent implantation.Methods Thirty-six patients of both sexes,aged 18-64 yr,of American Society of Anesthesiology physical status Ⅱ or Ⅲ,scheduled for elective tracheal stent implantation,were allocated into 2 groups (n =18 each) using a random number table method:four-way pipe fitting with LMA group (FWP-LMA group) and rigid bronchoscope group.LMA was inserted after anesthesia induction,and the four-way pipe fitting and anesthesia machine were connected to perform intermittent positive pressure ventilation in FWP-LMA group.A rigid bronchoscope was implanted,and jet ventilator was used to assist ventilation in rigid bronchoscope group.The development of intraoperative hyoxemia,hypertension and tachycardia was recorded.Blood gas analysis was performed before operation and at the end of operation to record pH value,the partial pressure of arterial oxygen and partial pressure of arterial carbon dioxide.The success rate of tracheal stent implantation at first attempt and development of postoperative pharyngeal complications were also recorded.Results Operation was canceled due to rigid bronchoscope implantation in one patient in rigid bronchoscope group.Compared with rigid bronchoscope group,the pH value and partial pressure of arterial oxygen were significantly increased,and the partial pressure of arterial carbon dioxide was decreased at the end of operation,the incidence of intraoperative hyoxemia,hypertension and tachycardia was decreased,the incidence of postoperative sore throat and hoarseness was markedly decreased,operation time was prolonged,and the success rate of tracheal stent implantation at first attempt was decreased in FWP-LMA group (P＜ 0.05).Conclusion The four-way pipe fitting with LMA produces better ventilation effect,induces slighter stress responses with fewer complications and can be safely used for airway management during tracheal stent implantation.
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Objective To evaluate the role of intestinal flora disturbance in development of postoperative cognitive dysfunction (POCD) in aged mice and the relationship with regulatory T cells (Treg) and T helper cells 1/T helper cells 2 (Th1/Th2) in the small intestine.Methods Thirty-six SPF healthy male C57BL/6J mice,weighing 45-50 g,aged 18 months,were divided into 3 groups (n=12 each) using a random number table method:control group (group C),POCD group and POCD plus VSL#3 group (group PV).POCD was induced by abdominal exploration.VSL#3 probiotics was given by intragastric gavage (300 μl per time,once a day) every 24 h for 7 consecutive days starting from the end of surgery in group PV.Morris water maze test was used to assess the cognitive function at day 7 after operation.Orbital venous blood samples were collected after the end of Morris water maze test,and animals were then sacrificed and small intestine and hippocampi were removed for measurement of the percentage of CD4+ CD25+ Foxp3+Treg,TCD4+IFN-γ+Th1 and CD4+IL-4+Th2 in the lamina propria of small intestine and plasma and expression of IL-4 and IFN-γmRNA in the lamina propria of small intestine,plasma and hippocampal tissues,and IL-4 mRNA/IFN-γmRNA ratio was calculated.Results Compared with group C,the percentage of CD4+CD25+Foxp3+Treg and CD4+IL-4+ Th2 in the lamina propria of small intestine and plasma was significantly decreased,the percentage of CD4+ IFN-γ+Th1 in the lamina propria of small intestine and plasma was increased,the expression of IL-4 mRNA in the lamina propria of small intestine,plasma and hippocampal tissues was down-regulated,the expression of IFN-γ mRNA in the lamina propria of small intestine,plasma and hippocampal tissues was up-regulated,IL-4 mRNA/IFN-γ mRNA ratio was decreased,the escape latency and swimming distance were prolonged,and the time spent in the target quadrant was shortened in group POCD (P＜0.05).Compared with group POCD,the percentage of CD4+ CD25+ Foxp3+ Treg and CD4+IL-4+ Th2 in the lamina propria of small intestine and plasma was significantly increased,the percentage of CD4+IFN-γ+Th1 in the lamina propria of small intestine and plasma was decreased,the expression of IL-4 mRNA in the lamina propria of small intestine,plasma and hippocampal tissues was upregulated,the expression of IFN-γmRNA in the lamina propria of small intestine,plasma and hippocampal tissues was down-regulated,IL-4 mRNA/IFN-γmRNA ratio was increased,the escape latency and swimming distance were shortened,and the time spent in the target quadrant was prolonged in group PV (P＜ 0.05).Conclusion Intestinal flora disturbance can promote the development of POCD in aged mice,which is related to the decreased percentage of Treg and Th1/Th2 imbalance in the small intestine.
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Objective To investigate the effect and mechanism of valproic acid in preventing astrocyte proliferation around the central canal of rats following spinal cord injury.Methods Forty-five Wister rats were divided into normal control group (n =5),injury group (n =20) and treatment group (n =20) according to random number table.Animal models of acute spinal cord injury were produced at T10 using Allen' s method by dropping a 10 g weight from a 15 mm height.Rats in treatment group received intraperitoneal injection of valproic acid (300 mg · kg-1 · d-1 in two divided doses) at 30 minutes postinjury.Instead,rats in injury group were injected with an equal volume of saline in the same way.Hindlimb function was evaluated using BBB scoring system at 1,3,7,and 14 days postinjury.Astrocytes proliferation around central canal and expression of glial fibrous acid protein (GFAP) were examined.Results In normal control group,few astrocytes around spinal central canal and a low expression of GFAP were detected.In injury group,astrocytes began to increase at 24 hours postinjury; fluorescence intensity for GFAP was 24.6 ± 3.6 at 24 hours,reached a peak of 69.2 ± 6.4 at 3 days,maintained a high level of 56.7 ± 5.6 at 7 days,and reduced to 35.4 ± 4.3 at 14 days,a level that remained higher than that in normal control group (11.2 ± 1.6).Whereas in treatment group at 3 and 7 days,astrocyte proliferation around spinal central canal was lower than that in injury group; GFAP expressions (47.8 ± 5.3 and 42.2 ± 6.7) were lower than those in injury group (F =177.6,P ＜ 0.05).At 3,7,and 14 days,BBB scores in treatment group (7.80 ± 0.83,12.00 ± 1.58,and 16.60 ± 1.12 respectively) were significantly higher than those in injury group (4.60 ± 0.54,6.65 ± 0.67,and 9.40 ± 1.14 respectively) (F =1 113.6,P ＜ 0.05).Conclusion After spinal cord injury,valproic acid reduces astrocyte proliferation around central canal via inhibiting GFAP expression to promote functional recovery.
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Objective To evalutate the effects of different doses of sufentanil combined with low target plasma concentration of propofol for induction of anesthesia on hemodynamics in patients undergoing coronary artery bypass grafting using Swan-Ganz catheter.Methods Fifty ASA physical status Ⅱ-Ⅲ patients (NYHA Ⅱ or Ⅲ) patients,aged 45-64 yr,with body mass index ≤ 30 kg/m2 and left ventricular ejection fraction (LVEF) ≥ 50 ％,scheduled for elective coronary artery bypass grafting,were randomly assigned into 2 groups (n =25 each) using a random number table:sufentanil 0.5μg/kg group (group S1) and sufentanil 1.0 μg/kg group (group S2).Central venous catheter and Swan-Ganz catheter were all placed via the right jugular vein before induction of anesthesia.Anesthesia was induced with iv injection of sufentanil 0.5 μg/kg (group S1) or 1.0 μg/kg (group S1),and 60 s later propofol was given by target-controlled infusion (target plasma concentraion 2 μg/ml).Rocuronium 0.8 mg/kg was administered when consciousness was lost.The patients were endotracheally intubated and mechanically ventilated.Before induction (T1),immediately after loss of consciousness (T2),immediately before intubation (T3),and immediately after intubation (T4),HR,mean artery pressure monitoring (MAP),central venous pressure (CVP),pulmonary arterial wedge pressure (PAWP),cardiac index (CI),stroke volume index (SVI),systolic vascular resistance and mixed venous oxygen saturation (Sv-O2) were recorded.The development of adverse cardiovascular events was recorded during induction of anesthesia.Results Compared with the baseline value at T1,the MAP and systolic vascular resistance were significantly decreased at T3 in group S2 (P ＜ 0.05),and no significant changes were found in the parameters of hemodynamics at T2-4 in group S1 (P ＞ 0.05).Compared with group S1,the MAP was significantly decreased at T3 and the incidence of hypotension was increased in group S2 (P ＜ 0.05).Conclusion For the patients undergoing coronary artery bypass grafting,the optimum dose of sufentanil for induction of anesthesia is 0.5 μg/kg when combined with low target plasma concentration of propofol.
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Objective To investigate the cause of air emboli during hysteroscopic surgery.Methods Thirty-five ASA Ⅰ or Ⅱ patients,aged 22-59 yr,with a body mass index of 18-25 kg/m2,undergoing hysteroscopic surgery under spinal anesthesia,were involved in this study.Electrocision and electric coagulation were performed using the electrotome during surgery.Air emboli in the common iliac vein,superior vena cava,inferior vena cava and heart were continuously monitored using color Doppler ultrasonic imaging.The patients were divided into 2 groups according to the occurrence of the air embolus:air embolus group and no air embolus group.The possible factors which induced air emboli were analyzed.Results Air emboli developed in 15 patients at ( 19 ±10) min after perfusion with 5％ glucose injection and the incidence was 43％.A small number of air emboli (the numberof bubble ＜ 10/s) occurred in 4 cases.A moderate number of air emboli (10/s≤ the number of bubble≤20/s) occurred in 7 cases.A large number of air emboli (the number of bubble ＞ 20/s) occurred in 4 cases.Compared with no air embolus group,the using time of electrotome was significantly prolonged in air embolus group ( P ＜ 0.05).Conclusion The cause of air emboli during hysteroscopic surgery may be related to the using time of electrotome.