During the COVID-19 epidemic, our national guidelines have suggested that surgical patients should wear a mask to decrease the potential transmission of COVID-19 in the operating room, as long as the condition allows. However, so far, there is no study to discuss the influence of wearing a mask on the ventilation and blood oxygenation status in patients of spontaneous breathing with supplementary oxygen through an anesthetic facemask. This is a before-after study in the same patient, and 10 healthy volunteers were recruited, by testing the arterial blood gas parameters at key time points before and after oxygen inhalation to evaluate the effects of two different supplementary oxygen methods (‘disposable medical mask + anesthetic facemask’ and ‘anesthetic facemask only’) on the oxygenation of subjects. Our data demonstrated whether wearing a disposable medical mask or not could effectively increase the oxygen supply of the subjects compared with the basic value before oxygen inhalation; however, compared with the group without mask, the arterial oxygen partial (PaO2) reduced significantly at each time points when subjects wearing a disposable medical mask. There was no significant difference in other parameters, and our data showed that age growth and smoking had no significant effects on the difference of PaO2 between the groups with and without masks. This study demonstrates effective oxygen supplementation through anesthetic facemask in subjects with spontaneous breathing who is wearing a disposable medical mask, whose pulse oxygen saturation and arterial oxygen saturation can reach 100% rapidly, and this provides a theoretical basis for the management of patients with disseminated respiratory diseases to wear masks in the operating room; however, the rate and amount of PaO2 increase are both decreased as compared to those who is not wearing a disposable medical mask during supplementary oxygenation. Whether this difference will affect the clinical outcome needs further study.
ObjectiveTo systematically review the efficacy and safety of laryngeal mask versus endotracheal tubes for laparoscopic surgery.MethodsPubMed, EMbase, The Cochrane Library, CNKI, WanFang Data and CBM databases were electronically searched to collect the randomized controlled trials (RCTs) about the efficacy and safety of laryngeal mask versus endotracheal tubes for laparoscopic surgery from inception to April, 2017. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then meta-analysis was performed by using RevMan 5.3 software.ResultsA total of 16 RCTs involving 1 593 patients were included. The results of meta-analysis showed that: there was no significant difference in the success rate of the first insertion (RR=0.99, 95%CI 0.96 to 1.02, P=0.55). The airway pressure of patients whose position were head higher than foot was significantly lower in the laryngeal mask group than in the tracheal intubation group (MD=–1.20, 95%CI –1.81 to –0.59, P=0.000 1), but there was no significant difference between two groups in reverse position patients (MD=0.48, 95%CI –0.90 to 1.87, P=0.49). The incidence of sore throat (RR=0.58, 95%CI 0.46 to 0.74, P<0.000 01), the incidence of blood stain (RR=0.48, 95%CI 0.30 to 0.77, P=0.002), the incidence of laryngeal spasm/bronchial spasm (OR=0.30, 95%CI 0.11 to 0.80, P=0.02) and the incidence of cough/hiccup (RR=0.10, 95%CI 0.07 to 0.15, P<0.000 01) in the laryngeal mask group were significantly lower than those in the tracheal intubation group.ConclusionThe current evidence shows that compared with tracheal intubation, laryngeal mask can effectively reduce airway pressure of patients whose position are head higher than foot. The risks of various complications are significant higher in tracheal intubation in laparoscopic surgery. Laryngeal mask can maintain patients' normal respiratory functions while reduce damage and do not increase the occurrence of reflux aspiration. Due to limited quantity and quality of the included studies, more high quality studies are needed to verify above conclusion.
ObjectiveTo explore the influence of general anesthesia with laryngeal mask and preoperative inhalation of budesonide aerosol on the incidence of respiratory adverse events during pediatric anesthesia recovery. MethodsA total of 100 child patients scheduled to undergoing inguinal hernia repair between December 2012 and February 2014 were randomly divided into two groups (group A and B) with 50 in each. All the patients underwent general anesthesia with laryngeal mask, while patients in group B inhaled budesonide aerosol before anesthesia. Then, we observed the incidence of adverse events in both groups, including laryngospasm, respiratory tract infection, and pulmonary complications. ResultsCompared with group A, patients in group B had a lower incidence of adverse events (P<0.05). ConclusionPreoperative application of budesonide aerosol inhalation can significantly reduce adverse events in the process of anesthesia recovery in children.
ObjectiveTo investigate the safety and feasibility of laryngeal mask general anesthesia as a replacement of tracheal intubation general anesthesia in the "three-port" thoracoscopic thymectomy via subxiphoid and subcostal arch for thymoma patients without myasthenia.MethodsFrom January 2018 to June 2019, clinical data of patients with thymoma who underwent the novel "three-port" operation in our institution were analyzed retrospectively. The patients were divided into two groups according to the anesthesia methods, including a tracheal intubation general anesthesia group and a laryngeal mask general anesthesia group. There were 70 patients in the tracheal intubation general anesthesia group, including 42 males and 28 females, with an average age of 45.83±15.89 years. There were 39 patients in the laryngeal mask general anesthesia group, including 26 males and 13 females, with an average age of 43.31±15.64 years. The clinical data of the two groups were compared.ResultsThe baseline characteristics of the patients in the two groups were well balanced (P>0.05). No massive bleeding, conversion to thoracotomy, postoperative myasthenia or death occurred in those patients. No patient with laryngeal mask anesthesia had a conversion to tracheal intubation anesthesia during the operation. There was no significant difference in the operation time, intraoperative bleeding, intraoperative maximum partial pressure of CO2, lowest partial pressure of oxygen and anesthesia effect score between the two groups (P>0.05). There was also no statistical difference in postoperative aspiration, gastrointestinal discomfort, length of hospital stay, pain score and patient satisfaction degree between the two groups (P>0.05). However, the anesthesia time before operation and the time of awake after anesthesia in the laryngeal mask anesthesia group were significantly shorter than those in the tracheal intubation general anesthesia group (P<0.05), and the incidence of transient arrhythmia, laryngeal discomfort and hoarseness in the laryngeal mask general anesthesia group was significantly lower than that in the tracheal intubation general anesthesia group (P<0.05).ConclusionThe "three-port" thoracoscopic thymectomy via subxiphoid and subcostal arch under laryngeal mask general anesthesia is safe and feasible in the treatment of thymoma without myasthenia, and can be recommended routinely.
Objective To investigate the curve correlation between ventilation pressure and tidal volume in assisted mechanical ventilation with facemask during anesthesia induction. Methods Between January and August 2015, 120 patients, American Society of Anesthesiology Ⅰ-Ⅱ, undergoing selective gynecological surgery were randomly divided into four groups: groups P5, P10, P15 and P20, with 30 patients in each group. Mask ventilation pressure for the four groups were respectively 5, 10, 15 and 20 cm H2O (1 cm H2O=0.098 kPa). Patients were ventilated by preset ventilation pressure and frequency based on different groups after loss of consciousness. Mean ventilation volume (mean value of three tidal volumes) and end-tidal carbon dioxide pressure (PetCO2) were recorded for analysis. Results There was no significant difference among the four groups in patient’s general condition (P>0.05). The tidal volume of assisted mechanical ventilation increased with ventilation pressure degrees, and the differences among the four groups were significant (P<0.05). After curve regression analysis, tidal volume and ventilation pressure showed a positive linear correlation when ventilation pressure was set at 5-20 cm H2O, and the correlation equation was: tidal volume = 33.612×ventilation pressure-53.155. PetCO2 in P5 group was lower than those in the other three groups (P<0.05), while there were no significant differences among groups P10, P15 and P20 (P>0.05). Conclusion When ventilation pressure is set at 5-20 cm H2O in assisted mechanical ventilation with facemask during anesthesia induction, tidal volume and ventilation pressure show a positive linear correlation.
Objective This is a meta-analysis of the efficacy of noninvasive ventilation (NIV) with helmet compared to NIV with face mask in patients with acute respiratory failure (ARF). Methods " Helmet, face mask or facial mask” and " mechanical ventilation or noninvasive ventilation” were used as key words both in Chinese and English to search all the trials in PubMed, OVID, Embase, Scopus and Cochrane Library, websites, reference lists of articles, CNKI and Wanfang Database from inception to December 2016. Two reviewers independently assessed the methodological quality of the trials and extracted information. Revman 5.3 was used for data analysis. Results Ten randomized controlled trials (RCTs) and six case-control trials were included. NIV with a helmet reduced the intubation rate (OR=0.35, 95%CI 0.24 to 0.51, P<0.000 01), in-hospital mortality rate (OR=0.51, 95%CI 0.34 to 0.76, P=0.001), and NIV-related complications (OR=0.10, 95%CI 0.06 to 0.15, P<0.000 01) compared to NIV with face mask. There was no significant difference in gas exchange between two groups. In the subgroup analysis, types of ARF and ventilation mode did not affect the intubation rate and the complications relevant to NIV, but NIV with helmet mainly decreased the in-hospital mortality of the patients with hypoxemic ARF or pressure support ventilation. Conclusions NIV with a helmet can decrease the endotracheal intubation rate, in-hospital mortality, and NIV-related complications of the patients with ARF. And helmet is as effective as face mask in improving the gas exchange. However, larger or multicenter RCTs are needed to analyze the role of NIV with a helmet in this condition.
摘要:目的:定量测定50 %小儿在喉罩表面涂抹丁卡因胶浆的情况下平稳拔除喉罩时呼气末七氟烷浓度。方法:25例择期行四肢及体表手术的患儿,高流量吸入七氟烷诱导并以七氟烷和氧化亚氮维持麻醉,不使用肌肉松弛剂及静脉麻醉药物,手术结束后停止吸入氧化亚氮,并维持设定的七氟烷浓度10min后拔除喉罩。根据Dixon序贯法确定喉罩拔除时的七氟烷浓度,每0.1 Vol%七氟烷为1个增减单位。患儿未出现咳嗽、牙关紧闭、体动、屏气及喉痉挛则认为拔除喉罩平稳。结果:50 %小儿平稳拔除喉罩时呼气末七氟烷浓度(EC50)为1.22 Vol%(95 %的置信区间分别为0.99 Vol%～1.49 Vol%)。结论:在喉罩表面涂抹丁卡因胶浆的情况下,3～8岁患儿喉罩满意拔除时呼气末七氟烷EC50值为1.22 Vol%。Abstract: Objective: To determine the concentration of sevoflurane where 50%( EC50 ) of the attempts to remove the laryngeal mask airway (LMA ) with the Teracainum Gel would be successful in children. Methods: Twentyfive nonpremedicated children, aged 38 years old, ASA physical status I, scheduled for extremities or peripherical surgery were enrolled in this study. General anesthesia was induced with sevoflurane and maintained with sevoflurane and nitrous oxide in oxygen. After the surgery, the target concentration was maintained for at least 10 min, and then the LMA was removed. Each target concentration was predetermined by the Dixon’s upanddown method (with 0.1 Vol% as a step size), starting at 1.20 Vol% concentration of sevoflurane. A removal accomplished without coughing, teeth clenching, gross purposeful movement, breath holding or laryngospasm, during or within 1 min after removal was considered to be successful. Results:The concentration of sevoflurane to achieve successful LMA removal in 50% of children was 1.22 Vol% (95%CL, 0.99 Vol%1.49 Vol%). Conclusion: The EC50 value of sevoflurane for LMA smooth extubation in children aged 38 years old with teracainum gel was 1.22 Vol%.
ObjectiveTo evaluate if intravenous lidocaine can reduce the stress response induced by fiberoptic bronchoscopy in patients under general anesthesia. MethodsSixty patients undergoing fiberoptic bronchoscopy under unconsciousness between November 2013 and July 2014 were randomly divided into two groups: lidocaine group (n=30) and control group (n=30). Patients in the lidocaine group received an intravenous injection of lidocaine for 1 mg/kg during induction and then continuous intravenous infusion of 2% lidocaine with a dose of 3 mg/(kg·h). The same volume of saline was given to patients of the control group in the same way. Laryngeal mask airway was placed after anesthesia induction. Variables of heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and pulse oxygen saturation were observed and recorded at five time points: before induction, immediately after induction, immediately after laryngeal mask airway placement, fiberoptic bronchoscopy across tracheal carina and before leaving examination room. Complications including cough reflex, toxicity reaction of local anesthetics, and injection pain were also observed. ResultsThe examination was successfully completed in all patients. Blood pressure and heart rate increased in all patients when fiberoptic bronchoscopy got across tracheal carina. There were no statistically significant differences in the two groups (P>0.05). Patients in the two groups had no statistic difference in tinnitus and numbness of tongue (P>0.05). Compared with the control group, patients in the lidocaine group had lower incidence of injection pain (P<0.05). ConclusionIntravenous lidocaine cannot suppress stress response induced by fiberoptic bronchoscopy effectively.
Objective To assess the effectiveness and safety of laryngeal mask airway (LMA) and endotracheal tube (ETT) for airway management in pediatric general anesthesia. Methods Randomized controlled trials were collected through electronic searches of the PubMed, The Cochrane Library, EMbase, CBM, WanFang Data, VIP, CNKI from the date of establishment to November 2010. All the related data that matched the standards were abstracted by two reviewers independently. The quality of the included trials was evaluated according to the Cochrane Handbook 5.0. RevMan 5.0 software was used for meta-analysis of the complications, success of insertion on the first attempt and hemodynamic changes. Results A total of 39 trials involving 2 612 patients were included. The results of meta-analyses showed that LMA was superior to ETT in terms of less cough (RR=0.21, 95%CI 0.15 to 0.28, Plt;0.000 01), laryngospasm or bronchospasm (RR=0.37, 95%CI 0.18 to 0.77, P=0.008) and agitation (RR=0.14, 95%CI 0.09 to 0.22, Plt;0.000 01) during emergency. The incidence of postoperative sore throat (RR=0.32, 95%CI 0.19 to 0.55, Plt;0.000 1), hoarse voice (RR=0.09, 95%CI 0.03 to 0.27, Plt;0.000 1), nausea and vomiting (RR=0.46, 95%CI 0.26 to 0.80, P=0.006) was significantly lower in the LMA group. The hemodynamic changes during insertion and extraction of LMA were more stable than ETT, such as the heart rate changes in insertion, extraction and post-extraction period (SMD= –1.18, 95%CI –1.59 to –0.77, Plt;0.000 01; SMD= –1.29 95%CI –1.72 to –0.86, Plt;0.000 01; and SMD= –1.51 95%CI –2.15 to –0.87, Plt;0.000 01, respectively) and the MAP changes in insertion, extraction and post-extraction period (SMD= –1.21, 95%CI –1.39 to –1.02, Plt;0.000 01; SMD= –1.31, 95%CI –1.77 to –0.85, Plt;0.000 01; and SMD= –0.85, 95%CI –1.24 to –0.46, Plt;0.000 1, respectively); but no significant differences in postoperative regurgitation and aspiration (RR=3.00, 95%CI 0.62 to 14.61, P=0.17) and successful insertion on the first attempt (RR=0.99, 95%CI 0.94 to 1.05, P=0.84) were found between the LMA and ETT groups. Conclusion Current evidence indicates that the laryngeal mask airway is superior to endotracheal tube in terms of fewer complications during emergency and after operation as well as stable hemodynamic changes. So, it is a selective, safe and effective airway management for children.
Objective To investigate the effective dose of remimazolam benzenesulfonate to suppress cardiovascular responses to laryngeal mask placement in elderly patients. Methods Elderly patients undergoing laryngeal mask anesthesia between March and June 2023 were selected. Combined with sulfentanil 0.2 μg/kg, remimazolam was used as induction hypnotic. The first patient was given remizolam benzenesulfonate 0.16 mg/kg infused by pump for 1 min. The dose of remimazolam for the next patient was determined by the biased coin up-and-down method based on the patient’s response to the laryngeal mask placement. The score of Modified Observer’s Assessment of Alert/Sedation, vital signs and anesthesia depth index (AI) were recorded during induction. Probit analysis was used to calculate the half effective dose (ED50), 95% effective dose (ED95) and half effective AI (AI50). According to the statistical requirements, at least 45 negative patients were required. Results A total of 53 elderly patients were enrolled in the study until the end of the trial. The ED50 and ED95 of remimazolam benzenesulfonate for inhibiting cardiovascular responses to laryngeal mask insertion were 0.154 mg/kg [95% confidence interval (CI) (0.034, 0.170) mg/kg] and 0.207 mg/kg [95%CI (0.190, 0.614) mg/kg], respectively. AI decreased during induction, with an AI50 of 64.119 [95%CI (60.609, 69.984)]. Conclusion When combined with 0.2 μg/kg sufentanil, infusing 0.2 mg/kg remimazolam benzenesulfonate for 1 min is effective and safe for laryngeal mask anesthesia induction in elderly patients.