A 58-year-old male patient is admitted to the hospital 6 months after receiving bilateral lung transplantation. He complains of increasing shortness of breath with a “barking” cough and inability to clear secretions over the past 2 months. He mentions that he has been sleeping in his recliner chair due to dyspnea when lying flat. He is afebrile with a HR of 88/min, BP of 140/80 mm Hg, SpO2 of 94% on room air, and a respiratory rate of 30/min. He is using his accessory neck muscles, and right-sided rhonchi are noted during the chest examination. Administration of bronchodilators fails to improve his symptoms. He is started on noninvasive positive pressure ventilation, which leads to a marked improvement.
Which of the following is the gold standard test to diagnose his condition?A. Pulmonary function testing with spirometry
Correct Answer: C
The patient described here has most likely developed tracheobronchomalacia with or without bronchial stenosis, which will require visualizing with a fiber-optic bronchoscope (C). Malacia is defined as greater than 50% reduction in the airway lumen during expiration. It can be localized to the anastomotic site or diffusely affect the donor airways. Clinical features include dyspnea that may be aggravated in the recumbent position, chronic “barking” cough, wheezing, inability to clear secretions, and recurrent infections. Spirometry (A) may show a reduction in FEV1 and forced expiratory flow at 25% to 75% but is not confirmatory. Variable obstructive pattern may be seen in flow-volume loops. A dynamic CT scan of the chest may show the respiratory change in airway lumen, but a standard CT scan will not be diagnostic (B). Bronchoscopy is the gold standard tool for diagnosing airway complications including tracheobronchomalacia. It allows for direct visualization of the dynamic luminal narrowing during expiration. It can be present alone or at a site of bronchial stenosis. A sputum culture (D) would help to diagnosis if this patient had pneumonia, but the chance of a pneumonia with the patient being afebrile and producing clear secretions is fairly low.
Management of tracheobronchomalacia can be challenging. Observation is recommended for asymptomatic disease. Medical management is initially considered for symptomatic disease and involves chest physiotherapy, mucolytics, and noninvasive positive pressure ventilation. More invasive options such as stenting and trachea-bronchoplasty may be considered for severe malacia that is localized to the central airways.