Effectiveness of the endotracheal tube cuff on the trachea: physical and mechanical aspects

Introduction

The inflation pressure of the endotracheal tube cuff can cause ischemia of the tracheal mucosa at high pressures; thus, it can cause important tracheal morbidity and tracheal microaspiration of the oropharyngeal secretion, or it can even cause pneumonia associated with mechanical ventilation if the pressure of the cuff is insufficient.

Objective

In order to investigate the effectiveness of the RUSCH® 7.5 mm endotracheal tube cuff, this study was designed to investigate the physical and mechanical aspects of the cuff in contact with the trachea.

Methods

For this end, we developed an in vitro experimental model to assess the flow of dye (methylene blue) by the inflated cuff on the wall of the artificial material. We also designed an in vivo study with 12 Large White pigs under endotracheal intubation. We instilled the same dye in the oral cavity of the animals, and we analyzed the presence or not of leakage in the trachea after the region of the cuff after their deaths (animal sacrifice). All cuffs were inflated at the pressure of 30 cmH₂O.

Results

We observed the passage of fluids through the cuff in all in vitro and in vivo experimental models.

Conclusion

We conclude that, as well as several other cuff models in the literature, the RUSCH® 7.5 mm tube cuffs are also not able to completely seal the trachea and thus prevent aspiration of oropharyngeal secretions. Other prevention measures should be taken.     

自主呼吸试验通过后拔管失败原因分析

目的:分析通过自主呼吸试验(SBT)后拔管失败的原因,提高撤机拔管的成功率。方法:回顾性分析重症监护病房(ICU)接受机械通气并通过SBT后拔管的126例患者的临床资料及其拔管失败原因。结果:拔管失败28例(22.22%),因呼吸系统原因导致拔管失败15例,其中气道分泌物过多且喘憋加重14例,呼吸骤停1例;低氧血症7例;呼吸性酸中毒3例,其中喉水肿1例,支气管狭窄1例;意识障碍加重3例,其中脑出血1例。拔管失败患者中,血白蛋白水平是拔管失败后患者病死率的保护因素。结论:仅通过SBT来指导撤机拔管可能有一定的局限性,除了呼吸系统原因外,氧合状态、中枢神经系统、营养状态等都可能对拔管结局产生影响,因此对于通过SBT进行脱机拔管的患者,仍应该充分评估呼吸道、中枢神经、心功能以及营养状态等多方面因素。     

复方利多卡因乳膏用于脑动脉瘤夹闭术麻醉预防心血管应激反应研究

目的观察复方利多卡因乳膏用于脑动脉瘤夹闭术全麻插管患者,旨在评价对抑制气管导管刺激引起的心血管应激反应的效果。方法选择40例急、慢诊脑动脉瘤夹闭术患者,ASA为Ⅱ~Ⅳ级,拟施全麻气管插管行动脉瘤夹闭术,并随机分为两组,每组20例。对照组(I组),不使用复方利多卡因乳膏涂抹气管导管,实验组(II组),将复方利多卡因乳膏均匀涂抹气管导管套囊及前端,麻醉诱导后行气管内插管。分别记录患者在麻醉前、插管前、插管时、变动体位、抬头消毒和拔管时平均动脉压(MAP)和心率(HR)。结果插管时与插管前,I组患者明显出现一过性MAP升高和HR增快。而II组插管刺激反应弱于I组。组间与同时刻比较,差异有统计学意义(P0.05)。在变动体位和抬头消毒时与插管前I组仍出现MAP升高和HR增快现象。而II组却无明显变化,组间与同时刻比较,差异有统计学意义(P0.05)。在拔管时与插管前,I组患者明显出现MAP升高和HR增快现象,而II组却弱于I组,组间与同时刻比较,差异有统计学意义(P0.05)。结论将复方利多卡因乳膏均匀涂抹气管导管用于脑动脉瘤夹闭术全麻插管患者,可以有效抑制气管导管刺激引起的心血管应激反应。     

经皮气管切开术后并发气管狭窄的相关因素分析

目的 分析经皮气管切开术后气管狭窄的影响因素,并探讨其对策.方法 选择2006年2月至2012年6月行经皮气管切开术286例患者为研究对象,就术后机械通气时间、气道反复感染、糖皮质激素不合理应用、气管切开位置过高和操作方法不当5种因素,采用Logistic回归进行多因素分析.结果 286例患者中发生气管狭窄43例,发生率为15.03％（43/286）.多因素分析结果表明,术后机械通气时间过长（x2=21.76,P＜0.01）,反复气道感染（r=18.21,P＜0.01）,糖皮质激素不合理应用（x2=9.65,P＜0.01）,气管切开位置过高（x2=4.51,P＜0.05）,操作方法不当（x2=4.33,P＜ 0.05）与术后并发气管狭窄有关.结论 经皮气管切开术后造成气管狭窄的影响因素是多方面的,术后机械通气时间和反复气道感染是其主要原因,其次是糖皮质激素不合理应用、气管切开位置过高及操作方法不当.     

鼻内或静脉给予右美托咪定抑制全身麻醉苏醒拔管期不良反应的比较

目的 观察比较鼻内或静脉给予右美托咪定（Dex）对全身麻醉苏醒拔管期不良反应的影响.方法 将120例ASA分级Ⅰ～Ⅱ级择期全身麻醉腹部手术患者按随机数字表法分为四组（每组30例）,术毕前10 min静脉组单次静脉给予Dex 0.5μg/kg（0.9％氯化钠稀释至10ml,缓慢静注,≥30 s）、鼻内1组鼻内滴入Dex 0.5μg/kg,鼻内2组鼻内滴入Dex 0.8μg/kg,对照组静脉给予相同容量的0.9％氯化钠.观察和记录四组不同时间点的收缩压、平均动脉压（MAP）、心率,记录睁眼时间、拔管时间和拔管期咳嗽发生率及咳嗽严重程度等.结果 静脉组、鼻内1组拔管时收缩压、MAP、心率均明显高于基础状态,差异有统计学意义（P＜0.05）;鼻内2组各时间点收缩压、MAP、心率比较差异无统计学意义（P＞0.05）.对照组拔管前1 min至拔管后5 min收缩压、MAP、心率均明显高于基础状态,拔管时至拔管后3 min明显高于同期静脉组、鼻内1组和鼻内2组,差异有统计学意义（P＜0.05）.四组睁眼时间、拔管时间比较差异无统计学意义（P＞0.05）.静脉组、鼻内1组和鼻内2组拔管前咳嗽和躁动发生率、拔管时咳嗽程度评分3分率均明显低于对照组[43％（13/30）,50％（15/30）,47％ （14/30）比70％ （21/30）; 17％ （5/30）,23％ （7/30）,20％ （6/30）比43％ （13/30）; 53％（16/30）,60％（18/30）,50％（15/30）比80％（24/30）],差异有统计学意义（P＜0.05）.结论 无论鼻内或静脉给予Dex均可有效预防苏醒拔管期应激反应;降低术后躁动、咳嗽发生率和严重程度;鼻内滴入Dex 0.8 μg/kg更安全.     

The preventive effects of natural adjuvants,G2 and G2F on tracheal responsiveness and serum IL-4 and IFN-γ (th1/th2 balance) in sensitized guinea pigs

OBJECTIVE:

The effects of natural adjuvants on lung inflammation and tracheal responsiveness were examined in sensitized guinea pigs.

METHODS:

The responses of guinea pig tracheal chains and the serum levels of interleukin-4 and interferon-gamma were examined in control pigs and three other groups of guinea pigs: the sensitized group and two other sensitized groups treated with either adjuvant G2 or adjuvant G2F (n = 7 for each group). Sensitization of the animals was achieved by injection and inhalation of ovalbumin.

RESULTS:

The results showed that sensitized animals had increased tracheal responsiveness and increased serum levels of interleukin-4 and interferon-gamma compared to controls (p<0.05 to p<0.001). Treatments with either G2 or G2F prevented the increase in tracheal responsiveness and serum interleukin-4 (p<0.01 to p<0.001). However, the serum levels of interferon-gamma and the interleukin-4-to-interferon-gamma ratio was increased in the treated groups (p<0.001 for all cases).

CONCLUSIONS:

These results indicate important preventive effects of two natural adjuvants, particularly G2, on the changes in tracheal responsiveness, serum cytokines and the interleukin-4-to-interferon-gamma ratio (T helper 1/T helper 2 balance) in sensitized guinea pigs.     

Comparison of the TruView infant EVO2 PCD™ and C-MAC video laryngoscopes with direct Macintosh laryngoscopy for routine tracheal intubation in infants with normal airways

OBJECTIVE:

Videolaryngoscopy has mainly been developed to facilitate difficult airway intubation. However, there is a lack of studies demonstrating this method''s efficacy in pediatric patients. The aim of the present study was to compare the TruView infant EVO2 and the C-MAC videolaryngoscope with conventional direct Macintosh laryngoscopy in children with a bodyweight ≤10 kg in terms of intubation conditions and the time to intubation.

METHODS:

In total, 65 children with a bodyweight ≤10 kg (0-22 months) who had undergone elective surgery requiring endotracheal intubation were retrospectively analyzed. Our database was screened for intubations with the TruView infant EVO2, the C-MAC videolaryngoscope, and conventional direct Macintosh laryngoscopy. The intubation conditions, the time to intubation, and the oxygen saturation before and after intubation were monitored, and demographic data were recorded. Only children with a bodyweight ≤10 kg were included in the analysis.

RESULTS:

A total of 23 children were intubated using the C-MAC videolaryngoscope, and 22 children were intubated using the TruView EVO2. Additionally, 20 children were intubated using a standard Macintosh blade. The time required for tracheal intubation was significantly longer using the TruView EVO2 (52 sec vs. 28 sec for C-MAC vs. 26 sec for direct LG). However, no significant difference in oxygen saturation was found after intubation.

CONCLUSION:

All devices allowed excellent visualization of the vocal cords, but the time to intubation was prolonged when the TruView EVO2 was used. The absence of a decline in oxygen saturation may be due to apneic oxygenation via the TruView scope and may provide a margin of safety. In sum, the use of the TruView by a well-trained anesthetist may be an alternative for difficult airway management in pediatric patients.     

伤残接受度与心理弹性对喉癌永久性气管造瘘患者病耻感影响的路径分析

目的探讨伤残接受度与心理弹性对喉癌永久性气管造瘘患者病耻感影响,并分析其影响路径。方法采用便利抽样法,选取2016年6—2018年8月在广西医科大学附属肿瘤医院住院部及门诊部就诊的喉癌永久性气管造瘘患者264例为研究对象。采用社会影响量表(SIS)、伤残接受度量表(AODS)、心理弹性量表(CD-RISC10)对其进行调查,对三者进行相关性分析并建立结构方程模型进行路径分析。发放264份调查问卷,有效回收256份。结果256例永久性气管造瘘患者病耻感、伤残接受度、心理弹性总分分别为(61.50±9.27)、(76.88±9.34)、(26.49±4.05)分。相关性分析显示,伤残接受度、心理弹性得分与病耻感呈负相关(P<0.01)。结构方程模型分析表明,喉癌气管造瘘患者伤残接受度和心理弹性对病耻感具有直接效应(β值分别为-0.43、-0.28),伤残接受度通过心理弹性间对病耻感的间接效应为-0.06。结论喉癌永久性气管造瘘患者病耻感水平较高,伤残接受度与心理弹性对病耻感有显著预测作用。     

老年吸入性肺炎患者早期纤维支气管镜吸痰的临床观察

目的观察早期纤维支气管镜吸痰用于老年吸入性肺炎的临床疗效,评价其实际应用价值。方法选择80例老年吸入性肺炎患者,随机分为观察组与对照组各40例,观察组采用早期纤维支气管镜吸痰进行治疗,对照组采用传统疗法进行治疗,对两组治疗后呼吸频率、心率、肺部湿罗音、影像学检查结果进行比较分析,观察组间是否存在统计学差异。结果应用早期纤维支气管镜吸痰治疗的观察组疗效明显优于使用传统疗法进行治疗的对照组,组间比较差异具有统计学意义(P<0.05)。结论早期纤维支气管镜吸痰治疗老年吸入性肺炎,疗效显著,值得临床推广应用。     

术前连接气管插管下体位摆放的改进与护理

目的减少体位变动过程中增加气道阻力，防止术后麻醉恢复过程中气道损伤。方法将临床60例体位翻动患者按照体位翻动变化过程分为平卧搬动、侧卧搬动、俯卧搬动3阶段，分别比较改进前后体位移动时动态阻力变化隋况，比较改进前后体位移动后管道移位率及麻醉后护理评分。结果改进前后平卧搬动、侧卧搬动、俯卧搬动阶段分别比较体位移动前后安全纬度动态阻力、麻醉后护理评分及咽通气道使用率，差异均有统计学意义（P〈0.05）。结论术前连接气管插管下改进体位摆放方法可增加安全纬度，减少口咽通气道使用率。