Effect of Inspiratory Flow on Methacholine Challenge in Children

Regulation of inspiratory flow alters the outcomes of the methacholine (MHC) challenge in adults and cough receptor sensitivity in children. The effect of inspiratory flow on the reproducibility of the MHC challenge in children is unknown. The aim of this study was to evaluate the effect of inspiratory flow alteration on the repeatabilty of the MHC challenge in children with and without asthma. Twenty‐five children undertook the MHC challenge on three different days by using a dosimeter connected to a setup that allowed regulation of inspiratory flow and pattern. Children were randomized to commence the challenges at 20 or 60 L/min, and the last challenge was performed at 20 L/min. The within‐subject standard deviation, 95% range for change, and doubling dose for the differing inspiratory flow (20 vs. 60 L/min) was more than twice that of when inspiratory flow was maintained at 20 L/min for both occasions. The range of the “limits of agreement” of the Bland and Altman plot was smaller when inspiratory flow was constant. For short‐term comparative individual studies in children, inspiratory flow should be regulated. Laboratories and research measuring change in airway hyperrepsonsiveness to MHC should determine and report reproducibility indices of the challenge so airway hyperresponsiveness changes can be interpreted meaningfully.     

Endotracheal involvement from atypical mycobacterium causing respiratory difficulty: Case report and literature review

Atypical mycobacterium infections often present as cervicofacial lymphadenitis in pediatric patients. Endotracheal involvement, however, is rare, and has not been previously described with imaging and photographs.An infant with natural killer T-cell deficiency was admitted with cough, rhinorrhea, and cervical lymphadenopathy. Laryngotracheobronchitis-type symptoms persisted and imaging revealed an intraluminal abnormality of the trachea. Endoscopy confirmed a mediastinal lymph node with intrusion into the tracheal lumen. Intraluminal biopsy was deferred due to concerns of airway loss. Biopsy of the associated cervical lymph node confirmed Mycobacterium avium-intracellulare infection. The patient was managed with antibiotics and steroids with clinical resolution of his respiratory symptoms.     

Nano-TiO2 particles impair adhesion of airway epithelial cells to fibronectin

Titanium dioxide engineered nanoparticles (nano-TiO₂) are widely used in the manufacturing of a number of products. Due to their size (<100 nm), when inhaled they may be deposited in the distal lung regions and damage Clara cells. We investigated the mechanisms by which short-term (1-h) incubation of human airway Clara-like (H441) cells to nano-TiO₂ (6 nm in diameter) alters the ability of H441 cells to adhere to extracellular matrix. Our results show that 1 h post-incubation, there was a 3-fold increase of extracellular H₂O₂, increased intracellular oxidative stress as demonstrated by 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) oxidation, and a 5-fold increase of phosphor-ERK1/2 as measured by Western blotting. These changes were accompanied by a 25% decrease of H441 adherence to fibronectin (p < 0.05 compared to vehicle incubated H441 cells). Pretreatment with the ERK1/2 inhibitor U0126 for 3 h, partially prevented this effect. In conclusion, short-term exposure of H441 cells to nano-TiO₂ appears to reduce adherence to fibronectin due to oxidative stress and activation of ERK1/2.     

精密输液器的使用对高压氧治疗中气管切开插管患者气道湿化的影响

目的：探讨精密输液器的使用对高压氧治疗中气管切开插管患者气道湿化的影响。方法：76例气管切开术后患者均采用精密输液器进行气道湿化，观察其治疗前和治疗第1、3、5、10天的刺激性咳嗽、痰阻次数、吸痰量、吸痰次数等指标。结果：至治疗后10天，患者的刺激性咳嗽、痰阻次数、吸痰量、吸痰次数等指标均显著改善（P〈0.01），痰液粘稠度亦显著降低（P〈0.05）。结论：使用精密输液器能达到理想的湿化效果，降低了患者的高气道反应，减少了对气道的刺激，并且操作简单、安全可靠，值得临床推广应用。     

SLIPA与经典喉罩的临床应用比较

目的全麻下行择期妇科腹腔镜手术的病人,进行SLIPA(Streamlined Liner of the Pharynx Air-way)或经典喉罩(laryngeal mask airway,LMA)的应用效果比较。方法 60例病人随机分成两组,所有病人使用相同的麻醉药物。有食管胃反流危险因素的病人被排除。评估两种通气道应用的容易程度;呼吸道密封效果;通气情况;插管反应;副作用。结果 SLIPA或LMA均容易插入和通气,除了SLIPA有较大的峰值气道压,分别是16.2 cmH2O±3.8 cmH2O,13.4 cmH2O±2.3 cmH2O(P=0.03),其它参数比较无明显差异。平均呼吸道密封压分别是24.1 cmH2O±5.4 cmH2O,25.7 cmH2O±6.4 cmH2O(P=0.2)。SLIPA或LMA的密封质量:均能允许低流量麻醉,环路最低气流量分别为558 mL/min±377 mL/min,573 mL/min±382 mL/min(P=0.88)。插管反应:插入2 min后的血压,心率与基础值,诱导后的血压比较,两组均无显著性差异。24 h的咽痛发生率:两组相比无差异(P=0.95)。结论应用SLIPA或LMA进行控制通气,两种通气道均较容易插入,气道管理满意。     

Safe extubation of a parturient using an airway exchange technique

The difficult obstetric airway is a well-recognised anaesthetic challenge but little emphasis is placed on the difficulty of performing a safe tracheal extubation. We report the use of an airway exchange technique to extubate a difficult obstetric airway and discuss the role of these techniques in the obstetric population.     

昏迷患者院前转诊气道管理的方案比较

目的 探讨对昏迷患者院前急救转运最佳气道管理方案.方法 选取2005~2010年院前昏迷患者127例(格拉斯评分8以下),分别给于口咽通气管(A组)、普通喉罩(B组)及气管插管(C组),根据病情常规治疗,观察一次性置管时间、院前重复置管及安全转运.结果 口咽通气管组和普通喉罩组一次性置管时间明显少于气管插管组(P<0.01),然而安全转运成功率气管插管组较口咽通气管组和普通喉罩组有明显优势(P<0.05).结论 气管插管组对院前昏迷患者安全转诊提供较安全的气道保护.     

Insights in particulate matter‐induced allergic airway inflammation: Focus on the epithelium

Outdoor air pollution is a major environmental health problem throughout the world. In particular, exposure to particulate matter (PM) has been associated with the development and exacerbation of several respiratory diseases, including asthma. Although the adverse health effects of PM have been demonstrated for many years, the underlying mechanisms have not been fully identified. In this review, we focus on the role of the lung epithelium and specifically highlight multiple cytokines in PM‐induced respiratory responses. We describe the available literature on the topic including in vitro studies, findings in humans (ie observations in human cohorts, human controlled exposure and ex vivo studies) and in vivo animal studies. In brief, it has been shown that exposure to PM modulates the airway epithelium and promotes the production of several cytokines, including IL‐1, IL‐6, IL‐8, IL‐25, IL‐33, TNF‐α, TSLP and GM‐CSF. Further, we propose that PM‐induced type 2‐promoting cytokines are important mediators in the acute and aggravating effects of PM on airway inflammation. Targeting these cytokines could therefore be a new approach in the treatment of asthma.