P036: A CASE OF UNDIAGNOSED TRACHEOMALACIA AFTER INDUCTION OF ANESTHESIA
Bernardine Cabral; Panumart Manatpon, MD; Laura Molina; John D Cabral; University of Florida
Introduction: Tracheomalacia is a serious disease which leads to an extreme degree of dynamic airway collapse. Congenital tracheomalacia is rare and manifests in infancy due to failure of tracheal cartilage to develop properly. In adults, tracheomalacia can be acquired and often unrecognized.
Case: A 42-year-old morbidly obese female (BMI 48.5) non-smoker, with past medical history of hypertension, diabetes, paroxysmal atrial fibrillation (on Eliquis), and iron deficiency anemia was scheduled for robot-assisted total hysterectomy for uterine fibroids. Three previous surgeries under general anesthesia at other hospitals were uneventful. Physical examination and CXR were unremarkable. After preoxygenation, the patient was induced with 50 mg lidocaine, 250 mg propofol, and 50 mg rocuronium. After intubation with a Glidescope, desaturation (80s) and increased airway pressures unresponsive to manual ventilation with 100% oxygen occurred. Auscultation revealed bilateral breath sounds with no wheezing. Fiberoptic bronchoscopy was performed and revealed extreme airway collapse just above the carina. Increasing PEEP to 20 cmH2O improved airway diameter observed by fiberoptic bronchoscopy. The peak inspiratory pressures were in range of 36-42 cmH20 with expiratory tidal volume of approximately 300 ml. The case was cancelled following discussion with the surgeon. Patient was reversed, extubated, and placed on BiPAP in the PACU. CT scan of the chest demonstrated normal tracheobronchial tree without compression. After an uneventful overnight ICU stay, the patient was discharged.
Discussion: Tracheomalacia refers to softness of respiratory cartilage, resulting in expiratory collapse and airway obstruction. The trachea responds physiologically to intrathoracic pressure changes, widening during inspiration and narrowing during expiration. Even during forced expiration due to coughing, this will not normally cause resistance to air flow. In contrast, expiratory tracheal collapse can occur with tracheal flaccidity. Increasing intraluminal pressure during expiration can prevent tracheal collapse.
Tracheomalacia can be acquired in adults and potentially results from injury from previous surgery, prolonged intubation or tracheostomy, chronic infection or inflammation, irritants, emphysema, and GERD. It is often not recognized. Symptoms associated with tracheomalacia including noisy breathing, chronic cough, shortness of breath, hoarseness, difficulty swallowing, and recurrent respiratory tract infections. These symptoms were not elicited in our patient.
Other diagnostic studies include fluoroscopy, MRI, and lung function studies.
Some cases may resolve spontaneously. Treatment also include CPAP to stent the airway open during expiration. Surgical stenting may be required in known severe cases.
In this case, the patient had no symptoms to suspect tracheomalacia. It was an incidental bronchoscopic finding after induction. She also responded to PEEP and CPAP. Further diagnostic studies may be warranted in the future if she is to undergo surgery and anesthesia.