Transtracheal 2-d ultrasound for identification of esophageal intubation

This prospective, blinded, observational, efficacy study is one of the first to evaluate ultrasound in detecting esophageal intubation, a significant source of morbidity and mortality. We utilized a convenience sample of patients undergoing elective surgery during July 2004 in an urban teaching hospital. Trained Emergency Physician sonographers performed transtracheal ultrasounds of intubations to identify esophageal intubation. In 35 of the 40 patients enrolled, there was intubation of the trachea, whereas esophageal intubation occurred in five patients. Sonographers correctly identified all five esophageal intubations, for a sensitivity of 100% (95% confidence interval [CI] 48–100). Ultrasound correctly identified 34 of 35 tracheal intubations and misidentified one resulting in a specificity of 97% (95% CI 90–100). It seems that transtracheal ultrasound may be an efficacious adjunct for detecting esophageal intubation.     

国产明视插管软镜与纤维支气管镜经鼻困难气管插管的比较*

目的比较国产明视插管软镜(VIS)与纤维支气管镜(FOB)引导经鼻困难气管插管的临床应用效果。方法择期选择困难气道患者60例,Mallampati评分为Ⅲ或Ⅳ级,美国麻醉师协会评级(ASA)Ⅰ或Ⅱ级,年龄22~68岁,体重53~82 kg,随机分为VIS组(V组)和FOB组(F组),每组30例。分别采用VIS和FOB引导经鼻气管插管。观察记录两组气管插管时间、气管插管成功率及气管插管相关并发症发生情况,记录麻醉诱导前(T_0)、麻醉诱导后(T_1)、声门暴露时(T_2)、气管导管进入声门即刻(T_3)的平均动脉压(MAP)、心率(HR)和脉搏血氧饱和度(SpO_2)。结果与T_0时比较,T_1时两组MAP明显下降、HR明显减慢(均P0.05);与T_1时比较,T_3时两组MAP明显升高、HR明显增快(均P0.05),两组间比较差异无统计学意义(P0.05);气管插管期间两组SpO_2均无明显降低。V组和F组气管插管时间分别为(76.0±18.0)和(80.0±20.0)s、一次气管插管成功率分别为96.7%和93.3%,两组间比较差异均无统计学意义(均P0.05);气管插管并发症发生率两组间比较差异无统计学意义(P0.05)。结论与FOB相比较,国产VIS引导经鼻困难气管插管同样安全可靠、快速有效、插管成功率高,气管插管并发症少。     

Neural network-based detection of esophageal intubation in anesthetized patients

Objective. To test whether a neural network-based method could differentiate between tracheal and esophageal intubation in anesthetized patients by recognizing breathing circuit pressure and flow waveform patterns.Methods. Tracheal tubes were placed in the trachea and in the esophagus of adult patients undergoing elective operations. After ensuring for proper oxygenation, ventilator settings were changed to 5 ml/kg tidal volume (VT) and 15 cpm and circuit pressure and flow were recorded for 15 seconds. Then, the breathing circuit was switched to the tube placed in the esophagus, and signals were recorded for an additional 15-second period. During off-line analysis, individual waveforms were separated. Tracheal breaths were labeled with a score of 1 while esophageal breaths were labeled with –1. A neural network was defined to learn to associate waveforms to their corresponding scores. Data from 54% of the patients were used to train the neural network. Data from the remaining subjects were used for testing.Results. Forty-six patients were studied. Neural network training was achieved with 100 tracheal and 94 esophageal waveforms from 25 patients. Neural network performance was tested on 84 tracheal and 76 esophageal waveforms from 21 subjects. The neural network assigned scores of 0.99 ±0.05 (mean ± SD) to tracheal waveforms and –0.99 ± 0.03 to esophageal waveforms. The difference between mean esophageal and tracheal scores was –1.99 with a 99.999% confidence range of –2.01 to –1.96. Any arbitrary cutoff threshold, ranging between –0.76 and 0.7, separated tracheal and esophageal score regions, yielding no false positive or negative results.Conclusion. A neural network differentiated consistently tracheal from esophageal intubation when the ventilation testmode was used. The ventilation mode employed is feasible in most adult patients undergoing elective procedures under general anesthesia. Further research is required to train neural networks to recognize esophageal intubation in different age groups and when different ventilation modes are applied.     

国产明视插管软镜与光棒在颈椎损伤患者气管插管中的应用比较*

目的比较国产明视插管软镜(VIS)与光棒(LW)用于颈椎损伤患者气管插管中的临床应用效果。方法颈椎损伤手术患者60例,随机分为国产明视插管软镜组(VIS组)和光棒组(LW组),每组30例。分别采用国产VIS和LW引导经口气管插管。记录两组气管插管时间、插管次数及成功率和插管相关并发症,观察两组麻醉前(T_1)、气管插管前(T_2)、气管插管后1 min(T_3)、气管插管后3 min(T_4)和气管插管后5 min(T_5)的平均动脉压(MAP)和心率(HR)。结果 VIS组气管插管时间(25.3±13.6)s,LW组气管插管时间(23.8±12.5)s,两组比较,差异无统计学意义(P0.05);两组患者一次气管插管成功率及总成功率比较,差异均无统计学意义(93.3%vs 93.3%,100.0%vs 100.0%,P0.05);与T_2时比较,T_3～T_4时两组患者MAP和HR均明显升高(P 0.05)。T_3～T_5各时点两组MAP和HR比较,差异均无统计学意义(P0.05)。两组气管插管相关并发症发生率比较,差异无统计学意义(10.0%vs 16.7%,P0.05)。结论国产VIS和LW均适用于颈椎损伤患者经口气管插管,气管插管时间短,成功率高,插管并发症少,对患者血流动力学影响较轻。     

明视插管软镜与可视喉镜在肥胖患者气管插管中的比较

目的比较明视插管软镜与可视喉镜在肥胖患者经口气管插管中的临床效果。方法择期经口气管插管全麻手术肥胖患者60例,体质指数(BMI)30 kg/m~2,美国麻醉师协会分级(ASA)Ⅰ或Ⅱ级,年龄22~60岁。采用随机数字表法将患者分为两组:明视插管软镜组(V组)和可视喉镜组(K组),每组30例。记录两组患者Cormark-Lehane镜下分级(简称C-L分级)、气管插管时间、试插次数、气管插管成功率及气管插管并发症。结果两组均声门暴露(C-L分级)良好(P0.05),V组和K组气管插管时间、气管插管成功率及一次气管插管成功率比较差异无统计学意义[(24.4±11.6)vs(22.3±13.2)s、100.0%vs 100.0%、90.0%vs 86.7%](均P0.05)。两组气管插管并发症比较差异无统计学意义(P0.05)。结论明视插管软镜和可视喉镜均适用于肥胖患者气管插管,具有声门暴露良好、插管快速、成功率高和并发症少等优点。     

Acoustic method respiratory rate monitoring is useful in patients under intravenous anesthesia

Respiratory depression can occur during intravenous general anesthesia without tracheal intubation. A new acoustic method for respiratory rate monitoring, RRa^® (Masimo Corp., Tokyo, Japan), has been reported to show good reliability in post-anesthesia care and emergency units. The purpose of this study was to investigate the reliability of the acoustic method for measurement of respiratory rate during intravenous general anesthesia, as compared with capnography. Patients with dental anxiety undergoing dental treatment under intravenous anesthesia without tracheal intubation were enrolled in this study. Respiratory rate was recorded every 30 s using the acoustic method and capnography, and detectability of respiratory rate was investigated for both methods. This study used a cohort study design. In 1953 recorded respiratory rate data points, the number of detected points by the acoustic method (1884, 96.5 %) was significantly higher than that by capnography (1682, 86.1 %) (P < 0.0001). In the intraoperative period, there was a significant difference in the LOA (95 % limits of agreement of correlation between difference and average of the two methods)/ULLOA (under the lower limit of agreement) in terms of use or non-use of a dental air turbine (P < 0.0001). In comparison between capnography, the acoustic method is useful for continuous monitoring of respiratory rate in spontaneously breathing subjects undergoing dental procedures under intravenous general anesthesia. However, the acoustic method might not accurately detect in cases in with dental air turbine.     

Response of lower esophageal contractility to changing concentrations of halothane or isoflurane: A multicenter study

A multiple-center study was performed to determine the relationship between lower esophageal contractility, clinical signs, and anesthetic concentration as expressed by minimum alveolar concentration (MAC). One hundred four American Society of Anesthesiologists Class I through III patients were exposed to isoflurane (with and without nitrous oxide) or halothane in concentrations of 0.5, 1.0, and 1.5 MAC. Heart rate and systolic blood pressure were continuously monitored. Both the amplitude and frequency of spontaneous and provoked lower esophageal contractions were measured in situ by using a 24-F probe equipped with provoking and measuring balloons. Combined results demonstrated statistically significant correlations (P<0.001) between lower esophageal contractility and MAC. Spontaneous lower esophageal contractions decreased from 1.10±0.12 (SEM) contractions per minute (0.5 MAC) to 0.42±0.05 (1 MAC) to 0.18±0.05 (1.5 MAC). Provoked lower esophageal contractility values decreased from 45±4 mm Hg (0.5 MAC) to 29±3 (1 MAC) to 19±2 (1.5 MAC). Heart rate changes did not correlate with MAC, and systolic blood pressure correlated in only one of three centers. Intracenter and intercenter analyses failed to demonstrate a significant relationship between lower esophageal contractility and heart rate or systolic blood pressure. No intracenter differences in either amplitude or frequency of lower esophageal contractions were observed, despite differences in volatile agents, induction techniques and agents, patient populations, and duration of anesthesia. Our studies indicate that lower esophageal contractility may be an indicator of anesthetic depth as reflected by MAC, but further studies are needed to quantify the effects of surgical stimulus, intravenous anesthetics, vasodilators, anticholinergics, calcium channel blockers, beta-adrenergic agonists, and the presence of a nasogastric tube.     

Pressure support ventilation via face mask in acute respiratory failure in hypercapnic COPD patients

Objective To test whether non-invasive ventilation via facial mask could reduce the need for tracheal intubation via when mechanical ventilation must be initiated in COPD patients.Design Open prospective interventional study.Setting General Intensive Care Service of a County Hospital.Patients We have studied 12 COPD patients during 14 episodes of acute exacerbation of chronic respiratory failure who failed to improve with intensive medical therapy and showed impairements in severe respiratory acidosis and/or hypercapnic encephalopathy leading their attending physicians to order mechanical ventilationInterventions In these circumstances, a trial of pressuresupport (PS) ventilation (Servo Ventilator 900C) via facial mask Vital Signs Inc.) was performed. The level of pressure support was adjusted to obtain a tidal volume>400 ml. If the patient deteriorated, tracheal intubation and standard mechanical ventilation were performed.Measurements and results Measurements are presented as means±SEM. A pressure-support level of 14±3 cmH₂O was used during a period of 8±4 h. Low levels of external PEEP were used in 4 patients, while it generated excessive leaks in the others. Significant differences (p<0.05 ANOVA for repeated measures) in data obtained on admission, when patients deteriorated and after pressure support was administered were only observed in PaCO₂ (68±3 versus 92±3 versus 67±3 mmHg), arterial pH (7.27±0.03 versus 7.19±0.02 versus 7.31±0.01). SaO₂ (60±4 versus 86±3 versus 92±1%) and respiratory rate (35±2 versus 32±2 versus 23±1 breaths·min^–1). Three patients needed intubation and one of them died in the ICU.Conclusion Non-invasive ventilation (pressure-support) via face mask may reduce the need for tracheal intubation in the severe hypercapnic failure of COPD patients.Presented in part at the 6th European Congress on Intensive Care Medicine. Barcelona October 1992. Supported by grant 93/0623 from Fondo de Investigationes Sanitarias     

Placement of esophageal stethoscope by acoustic criteria does not consistently yield an optimal location for the monitoring of core temperature

The esophageal stethoscope has evolved into a device for both acoustic and core temperature monitoring. To test whether routine placement according to acoustic criteria results in placement of the core temperature sensor in the region of contiguity between the esophagus and the heart, we determined the depth of placement electrocardiographically. All patients were undergoing nonthoracic elective operations requiring general anesthesia and tracheal intubation. First, we established that different observers selected the same esophageal depth within ±1 cm electrocardiographically, using the criterion of a symmetric biphasic P wave of maximal amplitude (7 patients). Then, in 30 more patients, we compared routine acoustic placements with the depths of the maximalamplitude biphasic P wave. Stethoscopes placed according to acoustic criteria were within ±3 cm of P-wave depths in 15 of 30 patients. In the remaining patients, measured discrepancies ranged up to 13.5 cm. We conclude that the prevailing stethoscope design, with a thermistor at the tip, below the acoustic window, does not ensure placement of the thermistor within the optimal region for monitoring of core temperature. A modification in design that would take advantage of the reliability of electrocardiographic positioning is suggested. Supported by National Institutes of Health grant HL-16910.     

Tracheal agenesis

Tracheal agenesis is a rare congenital anomaly. We report a case and review the cases previously reported. Clinical features that might indicate tracheal agenesis include antenatal polyhydramnios, severe respiratory distress, absence of an audible cry, failure to advance an endotracheal tube beyond the larynx, a palpable distal trachea, clinical improvement after esophageal intubation, and roentgenographic absence of a tracheal air column with an abnormal position of the carina. For immediate management of the affected infant, we recommend intubation of the esophagus with an endotracheal tube to provide an air passage, and determination of the level of the defect by careful use of contrast material and roentgenography. Infants having type I tracheal agenesis may benefit from immediate tracheostomy.     

Assisted head extension minimizes the frequency of dental contact with laryngoscopic blade during tracheal intubation

ObjectivesWe hypothesized that the assisted maintenance of head extension would reduce the frequency of direct contact between the laryngoscope blade and the maxillary incisors during tracheal intubation.MethodsSixty-eight patients undergoing elective surgical procedures under general anesthesia were enrolled in this prospective, randomized, controlled crossover study. A single experienced anesthesiologist performed the simulated tracheal intubations with a classic Macintosh laryngoscope. After reaching the sniffing position during direct laryngoscopy, tracheal intubations with and without maintaining the head extension (by an assistant) were simulated twice in each patient in random order. The occurrence of dental contact with the laryngoscope blade was recorded during the simulated tracheal intubation. The distance between the laryngoscopic blade and maxillary central incisors was assessed using a digital caliper. The angle of head extension and the glottic view were also evaluated.ResultsThe frequency of dental contact was lower with the assisted head extension than without it (25/68 [37%] vs 67/68 [99%], P < .001). The blade-to-tooth distance was longer with assistance than without it (1.8 ± 1.9 [0-8] mm vs 0.0 ± 0.1 [0-1] mm, P < .001). The angle of head extension was greater with assistance than without it (26.6° ± 5.8° [6.0°-37.4°] vs 19.9° ± 5.4° [3.4°-31.8°], P < .001). No significant difference was observed between 2 simulated tracheal intubations with regard to the glottic views.ConclusionThe assisted maintenance of head extension during the simulation of tracheal intubation reduced the frequency of dental contact with the laryngoscopic blade without compromising the laryngoscopic views. The results of this study suggest that assisted head extension during tracheal intubation may reduce the possibility of unexpected dental injury.     

单腔气管插管全身麻醉应用于二氧化碳气胸下胸腔镜食管癌根治术的麻醉效果研究

目的观察单腔气管插管全麻应用于二氧化碳CO2气胸下胸腔镜食管癌根治术的麻醉临床反应和血流动力学的变化。方法选择在单腔气管插管全麻下行胸腔镜食管癌根治术及低体重和身高矮的患者[美国麻醉医师协会(ASA)分级Ⅰ和Ⅱ级、美国纽约心脏病学会(NYHA)分级Ⅰ和Ⅱ级,体重(40.52±3.97)kg,身高(148.57±10.95)cm]60例,在术侧胸腔中缓慢充CO2气体(6~8 L/min),维持胸内压6~8 mm Hg,分别采集人工气胸前5 min(T1)、人工气胸后5 min(T2)、人工气胸后15 min(T3)、人工气胸后30 min(T4)、人工气胸后60 min(T5)、人工气胸后100 min(T6)、胸腔手术结束10 min(T7)的心率(HR)、血压(BP)、中心静脉压(CVP)、脉搏血氧饱合度(Sp O2)、气道压(Pa W)及呼气末二氧化碳分压(PETCO2)等指标和动脉血气指标。结果所有病例均顺利完成胸腔镜手术,各时间点均未发现明显的心律失常和严重并发症;CO2气胸后,T2~T6时的HR、CVP、Pa W、PETCO2和动脉血二氧化碳分压(Pa CO2)较T1时明显升高(P0.05);T2~T6时BP、动脉血氧分压(Pa O2)和血气pH值较T1时明显下降(P0.05);Sp O2在T3、T4时比T1时明显降低(P0.05),T5、T6时降低但差异无统计学意义(P0.05)。T7后除CVP仍高外,其余大多数指标恢复至基础值水平。结论低体重和身高矮小患者实施单腔气管插管全麻应用于CO2气胸下胸腔镜食管癌根治术时,其血流动力学相对基本稳定,为这类患者享有胸腔镜技术提供了一种可行的、相对安全的麻醉方法。     

超声引导下喉上神经阻滞联合ZX-KSHJ可视喉镜在肥胖患者清醒气管插管中的应用效果

目的 探讨超声引导下喉上神经阻滞联合ZX-KSHJ可视喉镜在肥胖患者清醒气管插管中的应用效果。方法 选择2018年1月－2020年1月该院收治的120例拟行气管插管全身麻醉的肥胖患者作为研究对象,使用随机数表法将患者分为两组,每组各60例。观察组采用超声引导下喉上神经阻滞联合ZX-KSHJ可视喉镜气管插管,对照组采用超声引导下喉上神经阻滞联合传统光学喉镜气管插管。观察两组患者声门显露成功率、一次性气管插管成功率、总插管成功率、成功插管的平均插管时间、插管过程中呛咳发生率以及呛咳程度、血流动力学和插管相关并发症发生情况。结果 观察组声门显露成功率、一次性气管插管成功率高于对照组（P < 0.05）,成功插管的平均插管时间短于对照组（P < 0.05）,插管后1 min（T₁）和5 min（T₂）患者心率（HR）、无创收缩压（SBP）和无创舒张压（DBP）低于对照组（P < 0.05）,经皮动脉血氧饱和度（SpO₂）高于对照组（P < 0.05）,口腔出血、咽喉部损伤和气道损伤等并发症总发生率低于对照组（P < 0.05）。结论 超声引导下喉上神经阻滞联合ZX-KSHJ可视喉镜气管插管,可提高肥胖患者声门显露成功率和一次性插管成功率,缓解血流动力学波动,减少插管相关并发症发生风险。     

电子胃镜与硬质食管镜取出食管嵌钝性异物的对比研究

目的评价经硬式食管镜及经电子胃镜取出食管嵌钝性异物的效果及经济性。方法回顾性分析2013年6月-2017年6月在该院接受内镜下食管嵌钝性异物取出术的60例患者的临床资料,按治疗方式的不同分为研究组和对照组,研究组经电子胃镜取出异物,对照组经硬式食管镜取出异物。记录两组患者的麻醉方式、治疗成功率、并发症发生率、住院时间及治疗费用。结果研究组13例采用局部麻醉,17例采用静脉麻醉,对照组全部釆用气管插管全麻。研究组和对照组治疗成功率差异无统计学意义(96.67%vs100.00%,P0.05)。研究组和对照组并发症发生率比较差异无统计学意义(0.00%vs 3.33%,P0.05)。研究组和对照组住院时间比较差异无统计学意义[(1.70±1.39)vs(2.20±1.10)d,P0.05]。研究组治疗费用较对照组明显减少[(2 022.00±1 787.45)vs(5 078.00±930.57)元,P0.05]。结论经电子胃镜与经硬质食管镜均为安全、高效的食管嵌钝性异物取出方式,经电子胃镜方式在简便性和经济性上具有更大优势。     

Tracheal rapid ultrasound exam (T.R.U.E.) for confirming endotracheal tube placement during emergency intubation

Objectives

This study aimed to assess the diagnostic accuracy and timeliness of using tracheal ultrasound to examine endotracheal tube placement during emergency intubation.

Methods

This was a prospective, observational study, conducted at the emergency department of a national university teaching hospital. Patients received emergency intubation because of impending respiratory failure, cardiac arrest, or severe trauma. The tracheal rapid ultrasound exam (T.R.U.E.) was performed during emergency intubation with the transducer placed transversely at the trachea over the suprasternal notch. Quantitative waveform capnography was used as the criterion standard for confirmation of tracheal intubation. The main outcome was the concordance between the T.R.U.E. and the capnography.

Results

A total of 112 patients were included in the analysis, and 17 (15.2%) had esophageal intubations. The overall accuracy of the T.R.U.E. was 98.2% (95% confidence interval [CI]: 93.7–99.5%). The kappa (κ) value was 0.93 (95% CI: 0.84–1.00), indicating a high degree of agreement between the T.R.U.E. and capnography. The sensitivity, specificity, positive predictive value, and negative predictive value of the T.R.U.E. were 98.9% (95% CI: 94.3–99.8%), 94.1% (95% CI: 73.0–99.0%), 98.9% (95% CI: 94.3–99.8%) and 94.1% (95% CI: 73.0–99.0%). The median operating time of the T.R.U.E. was 9.0 s (interquartile range [IQR]: 6.0, 14.0).

Conclusions

The application of the T.R.U.E. to examine endotracheal tube placement during emergency intubation is feasible, and can be rapidly performed.     

Fiberoptic-Guided and Blind Tracheal Intubation Through iLTS-D,Ambu® Auragain™, and I-Gel® Supraglottic Airway Devices: A Randomized Crossover Manikin Trial

BackgroundThe use of supraglottic airway devices (SADs) is becoming more widespread. However, there is little evidence to show which device is best in an emergent clinical scenario.ObjectiveWe compared both fiberoptic-guided and blind tracheal intubation through the Intubating Laryngeal Tube Suction-Disposal (iLTS-D), the AuraGain™, and the i-gel® in an airway manikin.MethodsThirty residents were included in a randomized trial to perform both fiberoptic-guided and blind tracheal intubation using the iLTS-D, the AuraGain, and the i-gel. The main endpoint was the total time taken to achieve successful fiberoptic intubation through the SAD. Additional endpoints included total time for blind intubation, SAD insertion time, tracheal tube insertion time, intubation success rate, fiberoptic view, and maneuvers performed to achieve tracheal intubation.ResultsAll participants performed fiberoptic intubation using all three SADs on the first attempt. The total time to fiberoptic tracheal intubation using the i-gel, AuraGain, and iLTS-D was 42 s, 56 s, and 56 s, respectively. The blind tracheal intubation success rate was 80% with the iLTS-D, 43% with the i-gel, and 0% with the AuraGain. The total time for blind tracheal intubation through the i-gel and the iLTS-D was 29 s and 40 s, respectively. Laryngeal view grades were significantly poorer with the iLTS-D compared to the other devices. The iLTS-D required significantly more maneuvers to achieve successful tracheal intubation.ConclusionsIn an airway manikin, the iLTS-D, AuraGain, and i-gel appear to be reliable devices for airway rescue and fiberoptic-guided tracheal intubation. The iLTS-D is recommended for blind tracheal intubation.     

HC 可视喉镜在急诊低年资住院医师紧急气管插管操作中的应用

目的：研究采用 HC 可视喉镜是否可以提高急诊低年资住院医师紧急气管插管的效率及成功率。方法选取急诊科需要进行紧急气管插管的患者共计80例,首先随机（随机数字法）分为低年资住院医师组（A 组）及高年资主治医师组（B 组）,然后每组再随机分为 HC 可视喉镜插管组（HC 组）及传统光学喉镜插管组（N 组）,比较每组的声门暴露成功率、一次插管成功率、插管总成功率、并发症情况以及成功插管病例的平均尝试次数和平均插管时间。结果（1）A-HC组的声门暴露成功率、一次插管成功率、插管总成功率依次为90％、70％、90％,均高于 A-N 组,依次为50％、20％、45％,P ＜0.05;并发症总发生率、成功插管病例的平均尝试次数、平均插管时间依次为15％、（1.28±0.43）次、（31.44±5.06）s,均低于 A-N 组,依次为45％、（1.89±0.79）次、（45.89±4.99）s,P ＜0.05;（2）B-N 组的声门暴露成功率、一次插管成功率、插管总成功率依次为80％、65％、80％,均高于 A-N 组,依次为50％、20％、45％,P ＜0.05;并发症总发生率、成功插管病例的平均尝试次数、平均插管时间依次为15％、（1.25±0.41）次、（39.31±4.23）s,均低于 A-N 组,依次为45％、（1.89±0.79）次、（45.89±4.99）s,P ＜0.05;（3）A-HC 组与 B-HC 组的上述各项指标比较,差异无统计学意义（P ＞0.05）。结论 HC 可视喉镜用于急诊低年资住院医师的紧急气管插管操作时,可提高声门暴露成功率、减少尝试次数、降低并发症发生率、缩短插管时间,可以提高紧急气管插管的效率及成功率,并且可能缩小其与高年资主治医师紧急气管插管操作的差距。     

The esophageal obturator airway--a review.

The esophageal obturator airway (EOA) was introduced for clinical use in 1973. There have been few controlled studies on its effectiveness or safety; those published had differing results--one showed no clinically significant difference in PaO2 and PaCO2 between EOA and tracheal tube, while two others reported slightly increased PaCO2. Subsequent modifications include the esophageal pharyngeal airway, esophageal gastric tube airway, and Vermont, or Pilcher, model. The EOA is indicated in the apneic or deeply unconscious patient. It is contra-indicated in the conscious or semiconscious patient, in children, for more than 1-2 hours, and in known cases of esophageal trauma or pathology. The most commonly reported hazard is esophageal perforation; others include tracheal intubation (which is actually the most common hazard), failure to seal mask, failure to pass tube, incorrect assembly of mask and tube, the tube's becoming an intragastric foreign body, and obstruction to intubation. While the tube is not the hazard-free device it was once thought to be, it has a place in emergency airway management in preventing insufflation of air into the stomach as well as aspiration of gastric contents.