Assessment of a New Method to Distinguish Esophageal from Tracheal Intubation by Measuring the Endotracheal Cuff Pressure in a Porcine Model

Objectives: With the knowledge of differences in anatomic structures between the trachea and the esophagus, the authors conducted an animal study to evaluate the usefulness of endotracheal cuff pressure in distinguishing endotracheal and esophageal intubations. Methods: Six swine were anesthetized and endotracheally intubated with 7.5-mm cuffed endotracheal tubes. The intubations were confirmed by fiber-optic bronchoscopy. Each pilot balloon was connected to a 10-mL syringe and a manometer via a three-way stopcock. The cuff pressures were measured for each 1-mL incremental filling of air (1–10 mL). After removal of the endotracheal tubes, each swine was then intubated with the same endotracheal tubes into its esophagus. The cuff pressures of the esophageal intubation were measured with the same procedure. The cuff pressures and the pressure–volume relationships in both intubations were compared. Results: The cuff pressure increased significantly in the esophageal intubation in comparison with the endotracheal intubation in all the comparisons from 1 mL to 10 mL (p = 0.028 for all Wilcoxon signed-rank tests). The slope of the pressure–volume curve of the cuff pressure was also significantly higher in the esophageal intubation during the inflation of the cuff on average (0.047 vs. 0.032 cm H₂O/mL; p = 0.001), particularly in the first 5 mL of air inflation. Conclusions: The cuff pressure in the esophageal intubation was significantly higher than that in the endotracheal intubation under the same inflated volume from 1 to 10 mL. This may provide the basis for an adjunctive, simple, rapid, and reliable method to verify endotracheal intubation.     

机械通气患者呼气末正压对中心静脉压的影响

【目的】评价机械通气时不同水平呼气末正压(PEEP)对中心静脉压(CVP)的影响。【方法】选择46例行机械通气并监测CVP患者,在不同水平PEEP(0、2、4、6、8、10、12、15、18cmH2O)时,分别测定CVP及心率(HR)、平均动脉压(MAP)、呼吸频率(RR)、经皮脉搏血氧饱和度(SpO2),脱机后再次测量各值并比较其差异性。【结果】PEEP对CVP有非常显著的影响(P<0.01)。PEEP≥12cmH2O患者的SpO2与PEEP≤4cmH2O时有显著性差异(P<0.01)。HR、MAP、RR与在不同PEEP相比较则差异无统计学意义。脱机与机械通气各项观察指标相比较有非常显著性差异(P<0.01)。【结论】随着PEEP水平增加,CVP逐渐增加。脱机测量CVP对患者不利,维持患者原PEEP水平测量CVP,可增加患者的安全性。     

Prevalence of Difficult Airway Predictors in Cases of Failed Prehospital Endotracheal Intubation

Background

Difficult airway predictors (DAPs) are associated with failed endotracheal intubation (ETI) in the emergency department (ED). However, little is known about the relationship between DAPs and failed prehospital ETI.

Objective

Our aim was to determine the prevalence of common DAPs among failed prehospital intubations.

Methods

We reviewed a quality-improvement database, including all cases of ETI in a single ED, over 3 years. Failed prehospital (FP) ETI was defined as a case brought to the ED after attempted prehospital ETI, but bag-valve-mask ventilation, need for a rescue airway (supraglottic device, cricothyrotomy, etc.), or esophageal intubation was discovered at the ED. Physicians performing ETI evaluated each case for the presence of DAPs, including blood/emesis, facial/neck trauma, airway edema, spinal immobilization, short neck, and tongue enlargement.

Results

There were a total of 1377 ED ETIs and 161 had an FP-ETI (11.8%). Prevalence of DAPs in cases with FP-ETI was obesity 13.0%, large tongue 18.0%, short neck 13%, small mandible 4.3%, cervical immobility 49.7%, blood in airway 57.8%, vomitus in airway 23.0%, airway edema 12.4%, and facial or neck trauma 32.9%. The number of cases with FP-ETI and 0, 1, 2, 3, or 4 or more DAPs per case was 22 (13.6%), 43 (26.7%), 23 (24.3%), 42 (26.1%), and 31 (19.3%), respectively.

Conclusions

DAPs are common in cases of FP-ETI. Some of these factors may be associated with FP-ETI. Additional study is needed to determine if DAPs can be used to identify patients that are difficult to intubate in the field.     

Continuous Positive Airway Pressure vs. Pressure Support Ventilation in Acute Cardiogenic Pulmonary Edema: A Randomized Trial

Background: Both non-invasive continuous positive airway pressure (nCPAP) and non-invasive pressure support ventilation (nPSV) have been shown to be effective treatment for acute cardiogenic pulmonary edema (ACPE). In patients with severe ACPE who are treated with standard medical treatment, the baseline intubation rate is approximately 24%. Study Objective: This study was conducted to compare the endotracheal intubation (ETI) rate using two techniques, nCPAP vs. nPSV. In addition, mortality rate, improvement in gas exchange, duration of ventilation, and hospital length of stay were also assessed. Methods: This prospective, multi-center, randomized study enrolled 80 patients with ACPE who were randomized to receive nCPAP or nPSV (40 patients in each group) via an oronasal mask. Inclusion criteria were severe dyspnea, respiratory rate > 30 breaths/min, use of respiratory accessory muscles, or PaO₂/FiO₂ < 200. Results: ETI was required in 0 (0%) and in 3 (7.5%) patients in the nCPAP group and in the nPSV group, respectively (p = 0.241). No significant difference was observed in in-hospital mortality: 2 (5%) vs. 7 (17.5%) in nCPAP and nPSV groups, respectively (p = 0.154). No difference in hospital length of stay was observed between the two groups, nor was there a difference observed in duration of ventilation, despite a trend for reduced time with nPSV vs. nCPAP (5.91 ± 4.01 vs. 8.46 ± 7.14 h, respectively, p = 0.052). Both nCPAP and nPSV were effective in improving gas exchange, including in the subgroup of hypercapnic patients. Conclusions: Both methods are effective treatment for patients with ACPE. Non-invasive CPAP should be considered as the first line of treatment because it is easier to use and less expensive than non-invasive PSV.     

急诊内科危重病人气管插管时机与方法的探讨

目的:总结急诊内科病人气管插管的特点,分析其治疗效果,并探讨其插管时机、方法与转归。方法:根据病人在急诊科治疗情况,将病人分成三组。第Ⅰ组23例,系到医院前已临床死亡;第Ⅱ组30例,经抢救无效在急诊科死亡;第Ⅲ组30例,经抢救病人在急诊科存活,后转入病房或急诊留观。结果:第Ⅰ组病人经口气管插管,抢救平均30分钟,无一例心跳呼吸恢复;第Ⅱ组虽经急诊CPR,但呼吸功能不能恢复正常,或因其原发病未能控制,最终在急诊科死亡;第Ⅲ组病人经口插管13例,经鼻插管17例,6例病人在急诊留观治疗后出院,12例病人经ICU或病房住院治疗后基本痊愈出院,另12例最终死亡。结论:急诊科所遇垂危病人,多数需气管插管者是由内科医师首诊实施。正确的插管方法和较高的成功率是直接影响病人转归的重要因素。     

机械通气病人气管导管的气囊压力与吸气峰压的关系

目的:探讨机械通气时应用最小闭合容量技术注气的气管导管的气囊压力与气道吸气峰压之间的关系。方法:37例用高容低张气囊气管导管插管的机械通气病人,应用最小闭合容量技术注气,并同步测定气囊压力和记录同一时间的气道吸气峰压,用统计学方法分析气囊压力和气道吸气峰压之间的关系。结果:应用最小闭合容量技术注气的气囊压力为13+6 mmHg(4—26 mmHg),气道吸气峰压为23+7 am H2O(15-40 cm H2O);气囊压力与气道吸气峰压之间呈直线正相关(r=0.762,P<0.001,n=37)。结论:应用最小闭合容量技术的气囊压力水平与气道吸气峰压有关,并随后者的增高而增高,当气道吸气峰压较高时,有可能对气管造成缺血性损害。     

Factors Associated with Failure of Noninvasive Positive Pressure Ventilation in the Emergency Department

Objectives: To determine the factors associated with failure of noninvasive positive pressure ventilation (NPPV) in patients presenting with acute respiratory failure to the emergency department (ED). Methods: The authors retrospectively analyzed patients admitted to the ED for acute respiratory failure (defined as a PaCO₂ level >45 mm Hg, and pH ≤ 7.35 or a PaO₂/FiO₂ ratio < 250 mm Hg) and who were treated with NPPV. NPPV was delivered routinely according to an institutional protocol. Failure of NPPV was defined as the requirement of endotracheal intubation at any time. Results: A total of 104 patients were included. NPPV failed in 31% (32/104), and the mortality was significantly higher in this group (12/32 [44%]) compared with patients who were not intubated (2/72 [3%]) (p < 0.0001). Factors associated with failure of NPPV were Glasgow Coma Scale score < 13 at ED admission (odds ratio [OR], 3.67; 95% confidence interval [CI] = 1.33 to 10.07), pH ≤ 7.35 (OR, 3.23; 95% CI = 1.25 to 8.31), and respiratory rate (RR) ≥20 min⁻¹ (OR, 3.86; 95% CI = 1.33 to 11.17) after one hour of NPPV. The negative predictive value for NPPV failure was 86% (95% CI = 70% to 95%) for RR ≥20 min⁻¹. In the multivariate analysis, pH ≤ 7.35 and RR ≥20 min⁻¹ after one hour of NPPV were independently associated with NPPV failure (adjusted ORs, 3.51; 95% CI = 1.29 to 9.62 and 3.55; 95% CI = 1.13 to 11.20, respectively). Conclusions: Patients with pH ≤ 7.35 and an RR ≥20 min⁻¹ after one hour of NPPV had an increased risk of subsequent endotracheal intubation.     

Performance of Endotracheal Intubation and Rescue Techniques by Emergency Services Personnel in an Air Medical Service

Background. Literature spanning the last two decades has identified potential harm associated with out-of-hospital endotracheal intubation performed by ground paramedics. Previous researchers have reported intubation success rates of 66% to 97% in the air medical setting. Objective. To examine the success of endotracheal intubation and rescue techniques performed by air medical personnel during the first eight years of operation of the air ambulance service. Methods. This study was a retrospective survey of health records utilizing data from LifeFlight of Maine's airway procedure quality review database, covering the first eight years of system encounters. Results. During the study period, 369 intubation encounters occurred. Rapid-sequence intubation medications were administered in 345 (93.5%) cases. Flight personnel successfully performed endotracheal intubation in 340 (92.1%) encounters. Unsuccessful intubations were managed with an alternative definitive airway, rescue airway, or bag–valve–mask. Laryngeal mask airway (n = 11) was the most commonly used rescue airway device. Conclusions. During the first eight years of operation of this air medical transport system, flight personnel were able to successfully perform endotracheal intubation in 92.1% of cases.     

Comparison of Endotracheal Intubation Skills With Video Laryngoscopy and Direct Laryngoscopy in Providing Airway Patency in a Moving Ambulance

BackgroundEarly and successful management of the airway in the prehospital and hospital settings is critical in life-threatening situations.ObjectiveWe aimed to perform endotracheal intubation (ETI) by direct laryngoscopy (DL) and video laryngoscopy (VL) on airway manikins on a moving track and to compare the properties of intubation attempts.MethodsOverall, 79 participants with no previous VL experience were given 4 h of ETI training with DL and VL using a standard airway manikin. ETI skill was tested inside a moving ambulance. The number of attempts until successful ETI, ETI attempt times, time needed to see the vocal cords, and the degree of convenience of both ETI methods were recorded.ResultsOverall, 22 of 79 individuals were men; mean age was 30.3 ± 4.5 years. No difference was found in the comparison of the two methods (p = 0.708). Time needed to see the vocal cords for those who were successful in their first attempt were between 1 and 8 s in both methods. In the VL method, time needed to see the vocal cords (p = 0.001) and the intubation time (p < 0.001) in the first attempt were shorter than in the DL method. The VL method was easier (p < 0.001). The success rate was 97.5% in DL and 93.7% in VL.ConclusionsThe VL method is rapid and easier to see the vocal cords and perform successful ETI. Therefore, it might be preferred in out-of-hospital ETI applications.     

经鼻与经口气管插管机械通气抢救呼吸衰竭的比较

目的：探讨经鼻和经口气管插管的临床应用价值。方法：采用一次性附有低压高容气囊的气管插管，对１０７例急性呼吸衰竭患者进行经纤维支气管镜引导下插管，经鼻与经口明视插管或盲插管，并进行两种插管方法的比较。结果：经鼻插管６２例次，经口插管５４例次（共１１６例次）；留管时间：经鼻插管平均１１．８天，经口插管平均６．６天，两组比较Ｐ＜０．００５；气管切开率：经鼻插管组为１２．９％，显著低于经口插管组４２．６％（Ｐ＜０．００１）；而拔管率经鼻插管组为５９．７％，则明显高于经口插管组４０．７％（Ｐ＜０．００５）。结论：经鼻气管插管机械通气优于经口插管气管插管机械通气，前者具有患者耐受性好、留管时间较长、并发症少等优点，可避免或减少气管切开。     

无创正压机械通气患者的心理体验及护理对策

目的了解无创正压机械通气患者的真实心理体验及护理需求。方法 2012年1-6月,采用质性研究中现象学研究方法,采用目的性抽样法选择曾经在兰州大学第一医院ICU接受过无创正压机械通气治疗的14名患者进行深入访谈,对访谈资料录音后进行整理,分析。结果患者在接受无创正压机械通气治疗时常忍受着折磨与痛苦,如身体上的不适、呼吸道分泌物清除困难、语言沟通受阻、人机不协调、活动受限等;并有心理异常,如焦虑和恐惧、孤独等。患者积极寻求支持与帮助,如专业技术人员的同情和支持、家人的支持等,并积极重视自己。结论正确、细致、周到的护理有利于无创正压机械通气患者的治疗与康复。     

有创与无创双水平气道正压通气序贯治疗急性呼吸窘迫综合征

目的:探讨有创与无创双水平气道正压通气(bi-level positive airway pressure,BiPAP)序贯治疗急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)的疗效。方法:将重症监护病房(intensive care unit,ICU)76例ARDS患者随机分为有创与无创BiPAP序贯治疗组(A组)38例和常规同步间歇指令通气(synchronized intermittent mandatory ventilation,SIMV)组(B组)38例。所有患者均按ARDS常规治疗,尽早气管插管行SIMV,当"ARDS控制窗"出现时,A组拔除气管插管,改用鼻面罩无创BiPAP序贯治疗,B组继续SIMV治疗,以SIMV+压力支持通气(pressure support ventilation,PSV)模式撤机。结果:2组患者"ARDS控制窗"出现时间、生命体征的指标和动脉血气分析的指标比较差异均无统计学意义(P0.05);与B组比较,A组有创通气时间及总机械通气时间均减少,入住ICU时间缩短,呼吸机相关性肺炎(ventilator associated pneumonia,VAP)发生率、病死率均降低(P0.05)。结论:有创与无创BiPAP序贯治疗ARDS的疗效显著,可明显缩短机械通气时间,降低VAP发生率及病死率。     

长期无创正压通气用于慢性阻塞性肺疾病患者的疗效及护理

目的 探讨长期无创正压通气用于慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)患者的临床疗效及其护理.方法选择因慢性阻塞性肺疾病急性加重并发Ⅱ型呼吸衰竭接受鼻(面)罩无创正压通气(non-invasive positive pressure ventilation...     

开胸手术单肺通气期间非通气侧肺实施持续气道正压对肺内分流和氧合的影响

目的 观察单肺通气期闻非通气侧肺实施持续气道正压（CPAP）对肺内分流和氧合的影响。 方法 40例择期开胸单肺通气行肺叶切除患者,随机分对照组（A组）和CPAP组（B组）,每组20例。单肺通气时A组病人非通气侧支气管导管与大气相通,B组病人非通气侧肺给予5cmH2O的CPAP处理。分别于单肺通气前,单肺通气30min,单肺通气结束,恢复双肺通气30min抽动脉血测血气分析,根据公式计算肺内分流率。 结果 A组病人在单肺通气30min及单肺通气结束时PaO2明显降低,而与单肺通气前比较Qs／Qt则明显增高（P〈0.05）。B组病人PaO2及Qs／Qt虽有改变但各时点之间比较差异无显著性（P〉0．05）。单肺通气30min及单肺通气结束时,PaO2B组较A组高,而Qs／Qt低于A组（P〈0．05）。 结论 单肺通气期间非通气侧肺实施5cmH2O CPAP可明显提高氧分压,减少肺内分流。     

无创正压通气治疗慢性阻塞性肺疾病急性加重期合并严重呼吸衰竭的临床研究

目的：评价无创正压通气（NIPPV）在救治慢性阻塞性肺疾病（COPD）急性加重期并严重呼吸衰竭患者中的临床疗效。方法：对2006年1月至2008年1月入选的47例COPD急性加重期并严重呼吸衰竭患者使用双水平无创正压呼吸机面罩辅助通气,患者均伴有不同程度的意识障碍,动态观察NIPPV治疗前和治疗后2h、8h、1d及3d动脉血气、神志、治疗后患者的转归,NIPPV的不良反应及并发症。结果：本组47例患者中,41例经NIPPV治疗2h、8h、1d及3d后与治疗前比较,PaO2明显升高P〈0．01,PaCO2明显降低P〈0．01,pH明显升高P〈0．01,均脱机出院,有效率达87．23％（41／47）;6例改为有创通气,其中3例经有创机械通气治疗后脱机成功,1例因上消化道出血死亡,2例自动出院。结论：双水平无创正压通气对有选择的COPD急性加重期并严重呼吸衰竭患者治疗疗效确切,它能迅速缓解病情,减少患者的气管插管和气管切开以及相应的并发症,提高生活质量。     

无创正压通气治疗COPD合并OSAHS临床疗效及对睡眠质量影响

目的:探讨无创正压通气治疗慢性阻塞性肺疾病(COPD)合并阻塞性睡眠呼吸暂停低通气综合征(OSAHS)临床疗效及对睡眠质量影响.方法:选取2017年8月至2019年3月北京大学第三医院延庆医院收治的COPD合并OSAHS患者120例作为研究对象,按照随机数字表法分为对照组和观察组,每组60例.对照组给与常规解痉、平喘、抑制炎性反应等基础治疗,观察组给与无创正压通气联合基础治疗,比较2组患者疗效及治疗前后氧分压(PaO2)、二氧化碳分压(PaCO2)水平及睡眠质量.结果:观察组患者治疗总有效率(96.67%)显著高于对照组(86.67%),差异有统计学意义(P<0.05).治疗前,对照组和观察组PaO2 、PaCO2 水平比较,差异无统计学意义(P>0.05);治疗7 d,相对治疗前,2组患者PaO2 水平升高,PaCO2 水平降低,但观察组患者改善程度更显著,差异有统计学意义(P<0.05).治疗前,对照组和观察组睡眠质量评分比较,差异无统计学意义(P>0.05);治疗7 d,相对治疗前,2组睡眠质量评分均下降,但观察组患者睡眠质量评分显著低于对照组,差异有统计学意义(P<0.05).结论:无创正压通气治疗COPD合并OSAHS能改善患者血气水平,提高临床疗效及患者睡眠质量.     

经食管超声心动图评价左侧卧位小潮气量呼气末正压单肺通气患者血流动力学变化

  目的  应用经食管超声心动图(transesophageal echocardiography, TEE)评价左侧卧位开胸手术患者采用小潮气量呼气末正压(positive end-expiratory pressure, PEEP)单肺通气时的血流动力学变化。  方法  选择本院美国麻醉医师协会(American Society of Anesthesiologists, ASA)分级Ⅰ-Ⅱ级择期行左侧卧位开胸肺叶切除手术患者10例。在全麻诱导后采用小潮气量呼气末正压通气, 潮气量4~6 ml/kg, PEEP 4~6 cm H₂O, 呼吸频率12~16次/min。维持呼气末二氧化碳(end-tidal carbon dioxide, EtCO₂)35~40 mm Hg, SpO₂ > 96%, 并持续至研究观察结束。全麻诱导后30 min(约中心静脉穿刺后15 min)时测量患者平卧位双肺通气时的心率(heart rate, HR)、血压(blood pressure, BP)、中心静脉压(central venous pressure, CVP), 同时应用TEE经胃左心室中段短轴测量左室射血分数(left ventricular ejection fraction, EF)、每搏量(stroke volume, SV)、心输出量(cardiac output, CO)、心脏指数(cardiac index, CI)、每搏指数(stroke index, SI)、左室收缩末期容积(left ventricular end-systolic volume, LVESV)、左室舒张末期容积(left ventricular end-diastolic volume, LVEDV)、左室内径缩短分数(left ventricular dimension fractional shortening, LVDFS)和体循环阻力(systemic vascular resistance, SVR)。平卧位测试完毕后将患者移至左侧卧位, 胸腔打开前单肺通气, 于胸腔打开后约15 min同样测定上述参数, 数据测量结束后撤出食管探头, 结束实验。  结果  在小潮气量PEEP通气模式下, 左侧卧位单肺通气时的SV和SI较平卧位双肺通气时显著增高, 分别为(69.23±20.01)ml vs.(56.97±22.02)ml和(40.67±8.35)ml/m² vs.(32.45±8.79)ml/m²(P < 0.05), 但HR、SBP、DBP和CVP两种体位比较差异无统计学意义; 且LVEF、CO、CI、LVESV、LVEDV、LVDFS和SVR比较差异也无统计学意义。  结论  在小潮气量呼气末正压通气模式下, 与平卧位双肺通气比较, 左侧卧位单肺通气不影响患者的心功能和血流动力学。     

无创双水平正压通气联合氧疗对重症支气管哮喘患者血气指标及肺功能的影响

目的:探讨无创双水平正压通气联合氧疗对重症支气管哮喘患者血气指标及肺功能的影响.方法:选取2018年1月～2019年12月接受治疗的104例重症支气管哮喘患者为研究对象,随机分为对照组和观察组,每组52例.对照组采用药物+氧疗方式治疗,观察组在对照组基础上联合无创双水平正压通气.对比两组患者血气指标和肺功能.结果:治疗...