Tracheobronchomalacia-Like Lung Collapse During Three Separate Trials of General Anesthesia

Abstract

To the Editor: We report a case of unexpected tracheobronchomalacia-like lung collapse. A 66-year-old woman (48 kg, 139 cm) was scheduled for right total hip arthroplasty. Preoperative chest radiograph was normal. We induced anesthesia with 4 mg midazolam followed by 7% sevoflurane inhalation in oxygen. Following endotracheal intubation, the patient's breath sounds decreased over the left lung. Bronchoscopy showed expiratory narrowing of the distal trachea and left main bronchus into a crescent shape (Figs. 1a and b). Although Pao2 was 354 mm Hg, surgery was postponed to evaluate the lung collapse.Figure 1.: Severe narrowing in the expiratory phase observed in the trachea and the left main bronchus (a, b). The left upper and lower bronchus almost closed in both expiratory and inspiratory phase (c). Bronchoscopy in the awake patient showed no abnormalities in the trachea and the left bronchus (d, e).Immediately upon recovery from anesthesia, the breath sounds of the left lung returned to normal and the collapse seen on bronchoscopy disappeared. Chronological CT scanning showed modest narrowing of the trachea, but the tracheobronchial tree was otherwise normal. Subsequent bronchoscopy with the patient awake was also unremarkable. For the second attempt, we induced and maintained anesthesia with sevofluorane. We also placed an epidural catheter, and administered 20 mL of 1.5% lidocaine with epinephrine, 1:200,000. As before, the patient's breath sounds decreased over the left lung. Bronchoscopy again showed severe, crescent-type narrowing of the distal trachea and main bronchus. However, we proceeded with the right total hip arthroplasty. On recovery from anesthesia, normal breath sounds returned over the left lung. For the third attempt for left total hip arthroplasty half a year later, we placed an epidural catheter, and then induced and maintained anesthesia with propofol and fentanyl. Although breath sounds were again reduced over the left lung and bronchoscopy showed severe narrowing of the distal trachea and main bronchus, we proceeded with the total hip arthroplasty. The distortion of the trachea and bronchus disappeared after recovery from anesthesia, and breath sounds returned over the left lung. In all three attempts, we observed tracheobronchomalacia-like collapse with induction of anesthesia, whereas bronchoscopy with the patient awake was completely unremarkable. However, we noted her breathing sounds were reduced during normal sleep. Therefore, the underlying pathology may also occur, at least partly, when the patient is asleep. Takeshi Yokoyama, DDS, PhD Koichi Yamashita, MD, PhD Masanobu Manabe, MD, PhD Department of Anesthesiology and Critical Care Medicine Kochi Medical School Nankoku City, Japan [email protected] Kathleen A. Sluka, PT, PhD Graduate Program in Physical Therapy and Rehabilitation Science University of Iowa Iowa City, IA