Tracheomalacia is characterized by flaccidity
of the tracheal support cartilage leading to tracheal collapse
resulting in respiratory distress and wheeze, especially when
increased airflow is required. If the condition extends further to
the main bronchi, it is termed tracheobronchomalacia. These disorders
should be considered when unexplained symptoms of wheezing or
coughing are present in young infants, especially if the symptoms
start four to eight weeks after birth and persist without signs of
viral infection [1].
Case Report
A six months old male infant was admitted at our
institution with history of repeated hospitalizations for wheeze and
respiratory distress. Born as a term neonate by normal delivery, his
neonatal period was uneventful. The infant developed first episode of
wheeze at two months of life and was nebulized with salbutamol.
At three months of life, he was admitted for
wheeze with respiratory distress and was treated as bronchiolitis for
about a week. His chest skiagram at admission was reported normal.
The infant used to have recurrent episodes of cough/wheeze for which
he was treated by a nearby physician with oral bronchodilators and
antibiotics.
At six months of age, he was readmitted at a
pediatric care hospital for severe respiratory distress with wheeze.
His blood counts were normal. The repeat skiagram and CT scan of the
chest showed hyperaeration of the left lung with consolidation of the
right upper lobe. Since the wheeze persisted despite repeated beta
agonist nebulizations and imaging showed obstructive hyperaeration of
the left lung, rigid bronchoscopy was performed to rule out foreign
body aspiration. No intraluminal pathology was identified. Following
this, the child was referred to us.
On admission, the infant was dyspneic with
bilateral wheeze and decreased air entry on the left side. The upper
GI barium study and echocardiography were within normal limits.
Fibreoptic bronchoscopy under local anesthesia with video monitoring
demonstrated dynamic compression of the trachea at the lower
one-third, which was exagge-rated during expiration consistent with
moderate tracheo-malacia. A similar finding at the orifice of the
left main bronchus suggesting bronchomalacia was observed and the
diagnosis of tracheobronchomalacia left side was made.
Beta-agonists were withdrawn and nebulized
ipratropium and oral steroids were continued. Over a period of five
days the wheeze and respiratory distress settled and the child was
able to maintain SpO 2 of
> 92% at room air. The infant was advised chest physiotherapy and
postural drainage, and discharged. During follow up the infant was
asymptomatic with satisfactory weight gain. Repeat skiagram at follow
up was normal except for hyperaeration of the left lung.
Discussion
The diagnosis of airway malacias presents a
clinical challenge because of the frequent overlap of symptoms with
more common childhood respiratory illnesses like asthma [1].
Fibreoptic bronchoscopy done under local anesthesia is the gold
standard for the diagnosis of dynamic airway lesions [2].
Dynamic compression of the left main bronchus had
presented as obstructive hyperaeration during the third episode of
wheeze. It has been documented that severe bronchomalacia of the main
bronchus acts as ball valve and produces hyperaeration of lung
(obstructive emphysema) [3]. Impaired drainage of secretions caused
by airway malacia results in backlog of secretions which may be
responsible for the consolidation of the right upper lobe [4].
In airway malacias the contour of airways is
maintained by the bronchial smooth muscle tone [5]. Infants with
congenital airway malacias, presenting with wheeze may not improve
with beta agonist nebulisation because in such lesions, beta agonists
by reducing the muscle tone can aggravate the pathology. The childs
improvement of respiratory problems with discontinuing of
beta-agonist and continuation of semisynthetic anticholinergics (ipratropium)
nebulization substantiates this. Though surgical interventions like
aortopexy may be required in severe cases, majority of milder forms
of airway malacias invariably improve with regular chest
physiotherapy and postural drainage [1].
This case highlights the important principle that
young infants presenting with recurrent wheeze and respiratory
distress with poor response to bronchodilators may be advised
flexible bronchoscopy as the initial investigation of choice for
early diagnosis and effective management of airway malacias.
Contributors: DV has conceptualized the study
and contributed to writing the manuscript. SK was involved in data
analysis, outcome assessment, literature review and writing the
manuscript. VEV was involved in critical analysis of the manuscript.
Funding: None.
Competing interests: None stated.
References
1. Carden KA. Tracheomalacia and
tracheobronchomalacia in children and adultsan in-depth review.
Chest. 2005;127:984-1005.
2. Austin J, Ali T. Tracheomalacia and
bronchomalacia in children: Pathophysiology, assessment, treatment
and anesthesia management. Pediatr Anesth. 2003;13:3-11.
3. Mayer S, Laura N, Gerald Z, Joseph A. Pediatric
intrathoracic large airway obstruction: Diagnostic and therapeutic
considerations. Pediatric Emergency Care. 1994;10:313-2.
4. Yalç1n E, Do ru D, Özçelik U, Kiper N. Airway
malacia disorders in children. Chest. 2006;130:304.
5. Panitch HB, Keklikian EN, Motley RA, Wolfson MR,
Schidlow DV. Effect of altering smooth muscle tone on maximal
expiratory flows in patients with tracheomalacia. Pediatr Pulmonol.
1990;9:170-6.
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