INTRODUCTION: Endobronchial ultrasound allows visualization of smaller structures for needle aspiration biopsy. Moderate sedation is required and airway patency may be compromised. Patients with obstructive sleep apnea (OSA) experience airway obstruction during these procedures. In this case report, a laryngeal mask airway (LMA) was used to maintain airway patency during endobronchial ultrasound in a patient with morbid obesity and OSA.
CASE PRESENTATION: The patient is a 60-year-old male whose complaints of hematuria led to a right nephrectomy for renal cell carcinoma. Initial chest imaging demonstrated mediastinal adenopathy. Several months later, a repeat scan documented an increase in the right paratracheal nodes to greater than 2 centimeters. Positron emission tomography failed to show metabolic activity of the enlarged mediastinal nodes or metastatic lesions. He denied hemoptysis. Any prior surgical procedures were not complicated by airway problems. He is 68 inches tall and weighs 138.3 kilograms, with a body mass index of 46 kilogram per meter squared. Endobronchial ultrasound guided fine needle biopsy was planned. Because of his large tongue and concerns over the potential for airway compromise during sedation and instrumentation, an LMA was chosen to maintain a patent airway. The larger diameter ultrasound bronchoscope does not pass easily through an endotracheal tube, and patient breathing becomes labored. After aperture bar removal, this bronchoscope passes easily through the size 5 and 6 LMA. Routine monitors were applied. The airway was anesthetized with 120 mg nebulized lidocaine 4%, followed by 80 mg delivered by atomizer to the base of the tongue and posterior oropharynx to abolish any gag reflex. While awake, a size 5 LMA Unique™ was inserted into the oropharynx. During insertion, a finger directed the cuff tip caudad into the hypopharynx. Cuff inflation required 25 milliliters of air. Air exchange was unimpeded and phonation was possible. A bite block was placed over the airway tube and between the teeth. When supine, lidocaine was instilled into the LMA without a cough or gag response. Supplemental oxygen was provided. Conscious sedation by an experienced endoscopy nurse was initiated. A diagnostic bronchoscope was inserted easily to visualize the LMA in good position over the glottis. The glottic structures and lung exam were normal. The larger ultrasound bronchoscope passed easily through the size 5 LMA. Ultrasound of the distal trachea localized the right paratracheal lymph node for six ultrasound guided fine needle aspiration biopsies. The procedure concluded after 70 minutes. Drug totals were midazolam 5 milligrams, propofol 1,120 milligrams, and fentanyl 200 micrograms.The patient maintained spontaneous respirations and a patent airway throughout the procedure. He awakened rapidly and smoothly. Upon command, he opened his mouth to allow removal of the LMA.
DISCUSSIONS: In the past fifteen years, the LMA has gained popularity as an effective airway device for routine surgical procedures and management of difficult airways. Outside of the operating room, few clinicians have opportunities to experience the efficacy of an LMA. But, pulmonary and critical care physicians need to become familiar with the device and its applications to airway management for procedures and resuscitation. With time, the LMA may play a greater role in endoscopy, whether the airway evaluation portends a greater potential for airway compromise, or an unexpected response to sedatives renders a patient apneic.
CONCLUSION: The LMA is effective for airway management in many clinical scenarios. For endobronchial ultrasound, the larger diameter bronchoscope works best when placed through the mouth. In selected patients at risk for airway compromise, the LMA should be considered as an airway alternative for ease of use, bronchoscope maneuverability, patient comfort and safety.
DISCLOSURE: Perry Nystrom, None.