Paediatric tracheobronchomalacia and its assessment by tracheobronchography

Flexible bronchoscopy in pulmonary diseases in children with congenital cardiovascular abnormalities

There is a lack of data describing the role of flexible bronchoscopy (FB) in evaluating pulmonary diseases in children with congenital cardiovascular abnormalities in China. Determining whether those children suffer from respiratory complications may be useful for future preoperative planning and family counseling. The present study aimed to investigate the features and FB-associated findings with respect to pulmonary diseases in children with congenital cardiovascular abnormalities. The role of FB in guiding the treatment and safety of procedures was also evaluated. A cohort of 57 children with congenital cardiovascular abnormalities underwent FB for pulmonary diseases between November 2013 and June 2015. The demographics, bronchoscopy diagnoses, cellular analysis and microbiology of bronchoalveolar lavage fluid (BALF), and the clinically valuable contributions and side-effects of FB were analyzed retrospectively. The bronchoscopies were performed in patients with a median age of 4 months (range, 9 days-9 years) and 9 patients were intubated and mechanically ventilated. The most common types of congenital cardiovascular abnormalities were atrial septal defect, ventricular septal defect and patent ductus arteriosus. External compression of airways, tracheobronchomalacia, laryngomalacia, and airway narrowing were the most common airway abnormalities revealed by FB. BALF cellular analysis revealed an elevated total cell count and neutrophil percentage; 19.2% specimens harbored an etiological agent. FB findings contributed towards the clinical management of 26.3% patients. The complications of FB were mild and transient. In the present study, the majority of patients with cardiovascular abnormalities exhibited other airway disorders. The present findings suggest that FB was a useful and safe tool in the evaluation of this specific group of children.

Tracheobronchomalacia diagnosed by tracheobronchography in ventilator-dependent infants

BACKGROUND

Tracheobronchomalacia prevalence in premature infants on prolonged mechanical ventilation is high.

OBJECTIVE

To examine the prevalence of tracheobronchomalacia diagnosed by tracheobronchography in ventilator-dependent infants, and describe the demographic, clinical and dynamic airway characteristics of those infants with tracheobronchomalacia.

MATERIALS AND METHODS

This retrospective review studies 198 tracheobronchograms performed from 1998 to 2011 in a cohort of 158 ventilator-dependent infants <2 years of age. Dynamic airway assessment during tracheobronchography determined the optimal positive end-expiratory pressure to maintain airway patency at expiration in those infants with tracheobronchomalacia.

RESULTS

Tracheobronchograms were performed at a median age of 52 weeks post menstrual age. The primary diagnoses in these infants were bronchopulmonary dysplasia (53%), other causes of chronic lung disease of infancy (28%) and upper airway anomaly (13%). Of those with bronchopulmonary dysplasia, 48% had tracheobronchomalacia. Prematurity (P=0.01) and higher baseline - pre-tracheobronchogram positive end-expiratory pressure (P=0.04) were significantly associated with tracheobronchomalacia. Dynamic airway collapse during tracheobronchography showed statistically significant airway opening at optimal positive end-expiratory pressure (P < 0.001). There were no significant complications noted during and immediately following tracheobronchography.

CONCLUSION

The overall prevalence of tracheobronchomalacia in this cohort of ventilator-dependent infants is 40% and in those with bronchopulmonary dysplasia is 48%. Infants born prematurely and requiring high pre-tracheobronchogram positive end-expiratory pressure were likely to have tracheobronchomalacia. Tracheobronchography can be used to safely assess the dynamic function of the airway and can provide the clinician the optimal positive end-expiratory pressure to maintain airway patency.

Tracheobronchomalacia in children: review of diagnosis and definition

Tracheobronchomalacia is characterised by excessive airway collapsibility due to weakness of airway walls and supporting cartilage. The standard definition requires reduction in cross-sectional area of at least 50% on expiration. However, there is a paucity of information regarding the normal range of central airway collapse among children of varying ages, ethnicities and genders, with and without coexisting pulmonary disease. Consequently, the threshold for pathological collapse is considered somewhat arbitrary. Available methods for assessing the airway dynamically--bronchoscopy, radiography, cine fluoroscopy, bronchography, CT and MR--have issues with reliability, the need for intubation, radiation dose and contrast administration. In addition, there are varying means of eliciting the diagnosis. Forced expiratory manoeuvres have been employed but can exaggerate normal physiological changes. Furthermore, radiographic evidence of tracheal compression does not necessarily translate into physiological or functional significance. Given that the criteria used to make the diagnosis of tracheobronchomalacia are poorly validated, further studies with larger patient samples are required to define the threshold for pathological airway collapse.

Tracheomalacia and bronchomalacia in children: pathophysiology, assessment, treatment and anaesthesia management

Tracheomalacia and bronchomalacia are becoming increasingly well recognized. Although pathologically benign conditions, they are responsible for considerable morbidity, occasional mortality and significant difficulties in the operating theatre and intensive care unit. We performed an extensive literature search to identify causal associations, methods of clinical and investigative assessment, treatment modalities and anaesthetic experience with these conditions.