Incorporated home-made long endotracheal tube: a useful option for treating mucus plugging following silicone stenting

Stenting is an effective method of treating airway stenosis. However, airway obstruction due to mucus plugging is problematic. Treatment of this has mainly been conservative. This report describes a patient with complicated tracheal stenosis treated with silicone hood stent, who experienced repeated episodes of airway obstruction due to sputum accumulation. A novel method of sputum clearance and self-care, using a long endotracheal tube within the silicone stent, is described. This procedure resulted in a stable and patent airway, and the patient was discharged smoothly after the procedure. No further respiratory symptom occurred during the follow-up period.     

Mechanisms of airway hyperresponsiveness in asthma

Abstract:   Airway hyperresponsiveness (AHR) is a fundamental abnormality in asthma. There are many potential factors contributing to the excessive airway response demonstrable on airway challenge. These range from abnormalities of airway smooth muscle, airway remodelling and airway inflammation to abnormalities in the neural control of airway calibre. None of these by themselves fully explains the abnormalities seen on the dose response curves of the asthmatic. In this review, the main mechanisms are described, together with recent evidence providing a pathway by which a number of these mechanisms may interact to cause AHR through abnormality in ventilation distribution and airway closure. There is now evidence for a close relationship between ventilation heterogeneity and AHR which could be exploited clinically.     

Difficult airway management

Airway management is unequivocally the most important responsibility of the emergency physician. No matter how prepared for the task, no matter what technologies are utilized, there will be cases that are difficult. The most important part of success in the management of a difficult airway is preparation. When the patient is encountered, it is too late to check whether appropriate equipment is available, whether a rescue plan has been in place, and what alternative strategies are available for an immediate response. The following article will review the principles of airway management with an emphasis upon preparation, strategies for preventing or avoiding difficulties, and recommended technical details that hopefully will encourage the reader to be more prepared and technically skillful in practice.     

The bronchial circulation—worth a closer look: A review of the relationship between the bronchial vasculature and airway inflammation

Until recently, the bronchial circulation has been relatively ignored in the research and clinical arenas, perhaps because of its small volume and seeming dispensability relative to the pulmonary circulation. Although the bronchial circulation only receives around 1% of the cardiac output in health, it serves functions that are critical to maintaining airway and lung function. The bronchial circulation also plays an important role in many lung and airway diseases; through its ability to increase in size, the bronchial circulation is able to provide lung parenchymal perfusion when the pulmonary circulation is compromised, and more recently the role of the bronchial circulation in the pathogenesis of inflammatory airway disease has been explored. Due to the anatomic variability and small volume of the bronchial circulation, much of the research to date has necessitated the use of animal models and invasive procedures. More recently, non‐invasive techniques for measuring bronchial blood flow in the mucosal microvascular network have been developed and offer a new avenue for the study of this circulation in humans. In conjunction with molecular research, measurement of airway blood flow (Q_aw) may help elucidate the role of the bronchial circulation in inflammatory airway disease and become a useful tool for monitoring therapy. Pediatr Pulmonol. 2010; 45:1–13. © 2009 Wiley‐Liss, Inc.     

不同内型哮喘小鼠模型中的小气道功能研究及其机制初探

目的 探讨不同内型哮喘小鼠模型中,小气道功能是否存在异常及其相关机制.方法 卵清蛋白(OVA)致敏、激发建立T2型哮喘模型,OVA联合臭氧暴露(OVA+ozone)建立非T2型哮喘模型.模拟强迫振荡系统检测小鼠小气道功能,激发试验检测气道反应性.酶联免疫吸附试验法检测支气管肺泡灌洗液(BALF)中的细胞因子;苏木精-伊...     

支气管镜引导联合透视下气道支架置入术治疗恶性气道狭窄的临床分析

目的研究支气管镜引导联合透视下气道支架置入术治疗恶性气道狭窄的疗效。方法对2003年01月至2013年05月因恶性气道狭窄置入气道支架的患者随访12个月,评估疗效及并发症。结果80例恶性肿瘤导致的气道狭窄患者均能顺利置入气道支架,术中无患者死亡,置入后呼吸困难评级、FVC、FEV1、PEF及Pa O2等指标均明显改善(P0.05),出现远期并发症的几率为11.25%。结论支气管镜引导联合透视下气道支架置入术对恶性气道狭窄能迅速的缓解呼吸困难症状,短期疗效显著,安全性好。     

Correlations between exhaled nitric oxide levels,blood eosinophilia,and airway obstruction reversibility in childhood asthma are detectable only in atopic individuals

The aim of this study was to compare in atopic and nonatopic asthmatic children correlations between two inflammation parameters, i.e., blood eosinophilia and exhaled nitric oxide (FE(NO)), and pulmonary function values, at baseline and after beta(2)-adrenergic bronchodilators. Ninety-two steroid-naive asthmatic children were evaluated: 26 were skin prick test- and RAST-negative (nonatopic subjects), whereas 66 were atopic, 15 being sensitized only to house dust mites (monosensitized) and 51 to mites and to at least one other class of allergens (polysensitized). Baseline spirometric values (FEV(1) and FEF(25-75%)) were similar in atopic and nonatopic groups (P > 0.1, each comparison). However, when compared to nonatopic subjects, atopic children showed a significantly higher degree of blood eosinophilia (3.0% and 6.7% white blood cell count, respectively; P = 0.0001) and higher FE(NO) levels (6.8 ppb and 16.0 ppb, respectively; P = 0.0001). While a positive correlation between FE(NO) levels and blood eosinophilia was observed in atopic children (r = 0.25, P = 0.041), no correlations between these two inflammation parameters and baseline pulmonary function values were demonstrated in any of the asthmatic groups. Inhalation of a beta(2)-agonist drug induced in the two asthmatic populations similar improvements in FEV(1) and FEF(25-75%) and no changes in FE(NO) levels or blood eosinophilia. However, only in atopic children positive correlations were found between percent variation in FEV(1) (delta%FEV(1)) and FE(NO) levels (r = 0.35, P = 0.006) or blood eosinophilia (r = 0.26, P = 0.04). Within the atopic group, no differences were found between mono- and polysensitized individuals in all parameters evaluated. Thus only in atopic children did parameters of inflammation correlate with airway obstruction reversibility.     

Plastic bronchitis: resolution after heart transplantation

Plastic bronchitis (PB) is a rare cause of obstructive airway disease in patients who have undergone partially corrective surgery for congenital heart disease (CHD). The etiology of plastic bronchitis in such patients is ill-defined, and treatment is ineffective. We report resolution of PB and severe obstructive airway disease after heart transplantation in a patient with CHD.     

Airway dimensions and pulmonary function in chronic obstructive pulmonary disease and bronchial asthma

Background and objective: COPD and bronchial asthma are chronic airway diseases with a different pathogenesis. Comparisons of differences in airway calibre by bronchial generation between these diseases and their importance to pulmonary function have not been fully studied. We investigated airway calibre and wall thickness in relation to pulmonary function in patients with asthma, COPD, asthma plus emphysema and normal subjects using CT. Methods: Sixty‐three asthmatic patients, 46 COPD, 23 patients with asthma plus emphysema and 61 control subjects were studied cross‐sectionally. We used a software with curved multiplanar reconstruction to measure airway dimensions from 3rd‐ to 6th‐generation bronchi of the right lower posterior bronchus. Results: Patients with COPD had increased wall thickness, but the airway was not narrow from the 3rd‐(subsegmental) to 6th‐generation bronchi. Mean bronchial inner diameter (Di) of 3rd‐ to 6th‐generation bronchi in patients with asthma or asthma plus emphysema was smaller than that of COPD patients and normal subjects. Airway luminal area (Ai) of 5th‐generation bronchi most closely correlated with pulmonary function in patients with stable asthma. Although Di was similar in patients with asthma and asthma plus emphysema, the Ai of 6th‐generation bronchi correlated significantly with pulmonary function in patients with asthma plus emphysema. Conclusions: Airway calibre in asthma may be smaller than in COPD. Airflow limitations correlated more closely with peripheral Ai in patients with asthma plus emphysema than in patients with asthma alone.     

Volume-pressure properties of the upper airway in normal subjects and patients with obstructive sleep apnoea

The aim of this study was to examine the volume-pressure (V-P) characteristics of isolated upper airways in normal subjects and patients with obstructive sleep apnoea (OSA) and to ascertain whether an increase in upper airway muscle activity affects these characteristics. We studied upper airway pressure changes during volume changes by inflation and deflation of air volumes of 5, 10, 15 and 20 mL without and with submental electrical stimulation, during voluntary closing of the glottis, in seven normal subjects and 13 OSA patients. Volume-pressure properties of the upper airway were assessed by elastance (Euaw) which was obtained from the slope of the regression line of the V-P relationships. Euaw in OSA patients was 0.52 +/- 0.08 cmH2O/mL, which was greater than in normal subjects (0.26 +/- 0.06 cmH2O/mL). Submental stimulation increased Euaw in both OSA patients and normal subjects (0.70 +/- 0.11 cmH2O/mL and 0.41 +/- 0.11 cmH2O/mL, respectively). These results suggest that upper airways of OSA patients during wakefulness are less collapsible than those of normal subjects, and that, in both groups, submental stimulation may stiffen the upper airway.     

Airway Dimensions in Fatal Asthma and Fatal COPD: Overlap in Older Patients

Abstract

In some patients with chronic asthma clinical and physiological similarities with COPD may exist, such as partial reversibility to bronchodilators and persistent expiratory airflow obstruction. However, pathological data comparing both diseases in patients of similar age and disease severity are scarce. We compared large and small airway dimensions in 12 younger (mean age 32 yrs) and 15 older (mean age 65 yrs) non-smoker adult fatal asthma patients with 14 chronic smokers with severe, fatal COPD (mean age 71 yrs). Using H&E, Movat pentachrome staining and image analysis, we quantified large airway basement membrane (BM) thickness (μm), submucosal gland area and large and small airway inner wall, smooth muscle and outer wall areas. Areas were normalized by BM perimeter (μm²/μm).

Younger adult fatal asthma patients had thicker BM, smooth muscle, and outer wall areas in both small and large airways when compared to COPD patients. In older asthmatics there was an overlap in BM thickness and airway structure in small airways. Inner wall layer in large and small airway level and submucosal gland areas were similar among groups. In conclusion, there are airway histological structural similarities between fatal asthma and fatal COPD. Older fatal asthmatics present overlapping airway structural features with younger adult fatal asthmatics and severe COPD patients. Our data contributes to a better understanding of asthma pathology in the elderly.     

Comparison of alveolar nitric oxide concentrations using two different methods for assessing small airways obstruction in asthma

Background and objective: Fractional exhaled nitric oxide (F_ENO) is considered a potentially useful biomarker for airway inflammation. A two‐compartment model (2CM) of pulmonary NO dynamics has been used for the evaluation of bronchial NO flux (J'awNO) and alveolar NO concentration (C_ANO) in asthmatic patients. Recently, the trumpet shape of the airway tree and axial diffusion (TMAD) model has been reported as a modification of the 2CM. This study was designed to determine the validity of C_ANO measurement using the TMAD model for assessing small airways inflammation in asthma. Methods: A total of 52 asthmatic patients and 12 normal control subjects were included in the study. Methacholine inhalation challenge and pulmonary function tests, sputum induction, and exhaled NO measurements at several flow rates were performed. J'awNO and C_ANO were calculated using both the 2CM (C_ANO _2CM, J'awNO _2CM) and TMAD models (C_ANO _TMAD, J'awNO _TMAD). Results: Both J'awNO (J'awNO _2CM and J'awNO _TMAD) and C_ANO (C_ANO _2CM and C_ANO _TMAD) were significantly higher in asthmatic patients than in control subjects. C_ANO _2CM was significantly correlated with FEV₁/FVC (r = ?0.35, P = 0.01), FEF_25–75 (r = ?0.45, P < 0.001) and sputum eosinophils (r = 0.32, P = 0.02). In contrast, C_ANO _TMAD was significantly correlated with FEF_25–75 (r = ?0.42, P = 0.002) but not with FEV₁/FVC or sputum eosinophils. Conclusions: C_ANO _TMAD is more specific as an indicator of small airways obstruction than C_ANO _2CM. Assessment of small airways obstruction using the TMAD model may clarify the role of the small airways in the pathogenesis of asthma.     

Pathophysiology of severe asthma: We’ve only just started

Severe asthma is defined by the high treatment requirements to partly or fully control the clinical manifestations of disease. It remains a problem worldwide with a large burden for individuals and health services. The key to improving targeted treatments, reducing disease burden and improving patient outcomes is a better understanding of the pathophysiology and mechanisms of severe disease. The heterogeneity, complexity and difficulties in undertaking clinical studies in severe asthma remain challenges to achieving better understanding and better outcomes. In this review, we focus on the structural, mechanical and inflammatory abnormalities that are relevant in severe asthma.     

Lower airway obstruction, bronchial hyperresponsiveness, and primary pulmonary hypertension in children

We investigated the prevalence and reversibility of lower airway obstruction (LAO) and its correlation with pulmonary artery pressure in children with primary pulmonary hypertension (PPH). The analysis was performed retrospectively in a cohort of children with PPH between 5-18 years of age. PPH was defined as mean pulmonary artery pressure (PAPm) >25 mmHg at rest, or >30 mmHg during exercise, with normal pulmonary capillary wedge pressure in the absence of other causes. Lower airway function was assessed by spirometry and maximal expiratory flow-volume curves. Lung volumes were measured by body plethysmography. Patients were assigned according to their pattern of lung function into "normal," "obstructive," and "restrictive" groups. The reversibility of LAO was defined as an increase of > or = 15% from baseline in forced expiratory volume at 1 sec (FEV1) and/or > or =20% in forced expiratory flow at 25-75% of forced vital capacity (FEF25-75%) in response to nebulized albuterol. An "obstructive" pattern was found in 23 children (59%), a "restrictive" pattern in 2 children (5%), and a "normal" pattern in 14 children (36%). Response to bronchodilator was documented in 78% of children with an "obstructive" pattern and in 22% of those with a "normal" pattern. The PAPm showed a significant positive correlation with the TLC, RV, and RV/TLC, but a negative one with the ratio FEV1/FVC. Our findings suggest that reversible LAO is the most common lung function abnormality among pediatric patients with PPH. Whether airway reactivity is a cause of or the result of PPH remains to be determined.     

Tracheobronchial laceration after balloon dilation for benign strictures: incidence and clinical significance

BACKGROUND: Although balloon dilation is a safe procedure, it can lead to laceration of the airway, causing bleeding, pneumothorax, pneumomediastinum, or mediastinitis. We therefore determined the incidence and clinical significance of tracheobronchial lacerations after balloon dilation for treatment of benign tracheobronchial strictures. METHODS: We evaluated 97 patients who had undergone balloon dilation in 124 sessions for the treatment of benign tracheobronchial strictures. The degree of airway laceration was evaluated bronchoscopically. The cumulative airway patency rate after balloon dilation was compared in patients with and without lacerations using Kaplan-Meier survival curves and log-rank testing. RESULTS: There were 64 tracheobronchial lacerations (51.6%) during the 124 sessions of balloon dilation. Of these, 60 were superficial and 4 were deep, but there were no incidents of transmural laceration. In patients with lacerations, mild chest pain (n = 5), blood-tinged sputum (n = 21), and pneumomediastinum (n = 2) occurred, but all resolved completely within 24 h. All superficial lacerations healed spontaneously within 1 month, and all deep lacerations healed 2 to 9 months after conservative treatment. During the follow-up period, the median cumulative airway patency period in patients with and without lacerations was 24 and 4 months (p < 0.05), respectively. CONCLUSION: Laceration secondary to balloon dilation in the tracheobronchial tree is relatively common but rarely progresses to transmural laceration and may improve patency outcomes.