Excessive Dynamic Airway Collapse Detected Using Nondynamic CT

Complete expiratory central airway collapse at general anesthesia recovery: a case report

Expiratory central airway collapse is a degenerative tracheobronchial disease that is often overlooked because of its nonspecific clinical features. A man was admitted for evaluation of tracheal nodules. Following bronchoscopic biopsy, a significant increase in airway pressure occurred during anesthesia recovery. Laryngospasm was suspected, and tracheal intubation was performed. Bronchoscopy revealed an almost completely collapsed tracheal lumen. A Y-shaped silicone stent was placed using a rigid bronchoscope to support the airway, allowing spontaneous ventilation to resume. A retrospective review of the images suggested a diagnosis of excessive dynamic airway collapse. The silicone stent was removed after 2 weeks because of discomfort, and no subsequent dyspnea was observed. This case highlights that excessive dynamic airway collapse is easily missed. Anesthesiologists must be educated on this condition, maintain a thorough understanding of the patient's state and illness, and have emergency airway equipment readily available to restore ventilation promptly in cases of severe airway collapse.

Excessive dynamic airway collapse during general anesthesia: a case report

Background

Excessive dynamic airway collapse (EDAC) is an uncommon cause of high airway pressure during mechanical ventilation. However, EDAC is not widely recognized by anesthesiologists, and therefore, it is often misdiagnosed as asthma.

Case presentation

A 70-year-old woman with a history of asthma received anesthesia with sevoflurane for a laparotomic cholecystectomy. Under general anesthesia, she developed wheezing, high inspiratory pressure, and a shark-fin waveform on capnography, which was interpreted as an asthma attack. However, treatment with a bronchodilator was ineffective. Bronchoscopy revealed the collapse of the trachea and main bronchi upon expiration. We reviewed the preoperative computed tomography scan and saw bulging of the posterior membrane into the airway lumen, leading to a diagnosis of EDAC.

Conclusions

Although both EDAC and bronchospasm present as similar symptoms, the treatments are different. Bronchoscopy proved useful for distinguishing between these two entities. Positive end-expiratory pressure should be applied and bronchodilators avoided in EDAC.

Exertional Dyspnea and Excessive Dynamic Airway Collapse

Excessive dynamic airway collapse is a relatively new diagnosis separate from tracheobronchomalacia that is manifested by functional collapse of the large airways. Most commonly described in patients with underlying obstructive lung disease such as chronic obstructive pulmonary disease and asthma, it may contribute to increased dyspnea, cough, or exacerbations. There are few data published on the role of excessive dynamic airway collapse as related specifically to exercise. It was recently described as the cause for exertional dyspnea in individuals without underlying lung disease.