Tracheomalacia

Where it collapses tells you when it obstructs - intrathoracic malacia collapses on expiration and gives expiratory stridor; extrathoracic malacia collapses on inspiration. Abnormal expiratory noise with a clean inspiration on auscultation is the classic finding.

Get the dynamic study, not the static one - bronchoscopy during spontaneous respiration is the gold standard and shows loss of the semicircular shape with the posterior membrane bulging in. Expiratory-phase or cine CT and cine fluoroscopy with contrast swallow add the extrinsic-compression picture. PFTs may read obstructive but do not make the diagnosis alone, and sedation itself changes airway dynamics enough to distort the study.

Positive pressure is the treatment - CPAP stents the collapsing segment and is the option when conservative management fails, both acutely and after the case.

Extubation is the moment of risk - the tube was splinting the segment, and the airway can collapse once it is out. Have CPAP ready before extubation, and expect reintubation to be harder than the first attempt — awake fiberoptic is the fallback.

Post-thyroidectomy airway obstruction - tracheomalacia after thyroidectomy runs under 1%, while a compressive hematoma at 1% to 2% is the more common cause of obstruction in the first 24 hours; after 24 hours think hypocalcemic laryngeal dysfunction, which typically shows at 24 to 48 hours as stridor. Definitive treatment of a hematoma is opening the incision to evacuate it.

Secretions and infection - collapse impairs clearance, so expect a productive cough, recurrent respiratory infections, and a patient who needs chest physiotherapy. Reflux is both an association and an aggravator, and pediatric feeding regimens are built around avoiding aspiration.

Pediatric specifics - congenital expiratory stridor starts at 4 to 6 weeks and worsens with crying, feeding, activity, and the supine position while easing at rest. A child with a vascular ring lies with head and neck hyperextended to stretch the trachea; that is a compensation, not a positioning error. Isolated congenital tracheomalacia usually resolves by 12 to 24 months.

Procedures they come back for - silicone stent placement needs general anesthesia and rigid bronchoscopy. Aortopexy carries risks of pneumothorax, pleural effusion, atelectasis, phrenic nerve palsy, and bleeding, and short-segment disease may get tracheal resection with anastomosis.

Tracheomalacia is structural weakness of the tracheal cartilage that lets the airway collapse dynamically. The trachea is held open by 16 to 20 incomplete U-shaped hyaline cartilage rings with a membranous posterior wall; in malacia the rings flatten and the posterior membrane bulges inward, cutting anteroposterior caliber. Some expiratory narrowing is normal — up to about 30% of diameter in an infant during forced expiration — but collapse beyond 50% obstructs ventilation. Because flow follows Poiseuille's law, a small loss of lumen costs a large amount of airflow. Primary disease is congenital cartilage immaturity, common in prematurity and present in up to 75% of patients with tracheoesophageal fistula. Acquired disease follows prolonged or repeated intubation — the most common adult cause — COPD, relapsing polychondritis, or extrinsic compression by goiter, vascular ring, or mediastinal mass.