To the Editor:
Since first described by Oswalt in 1977, pulmonary edema occurring after extubation complicated by laryngospasm has been well reported in the postsurgical patient. We describe successful treatment of hypoxemia from postobstructive pulmonary edema using nasal bilevel positive airway pressure (BiPAP) in a postsurgical patient unable to tolerate a standard continuous positive airway pressure (CPAP) mask.
A previously healthy 22-yr-old man (5 feet 7 inches and 84 kg) presented for placement of a tissue expander in his right calf under general anesthesia. In the operating room, a smooth intravenous induction was accomplished and he was atraumatically intubated on direct laryngoscopy with one attempt. After uneventful surgery and reversal of neuromuscular blockade, the patient was slow to awaken from anesthesia. He was extubated when breathing spontaneously and displaying purposeful movement. Immediately, he developed laryngospasm which was treated promptly and apparently effectively with positive airway pressure by mask. Thereafter, he was transported to the postanesthesia care unit with oxygen insufflation.
Upon arrival to the postanesthesia care unit, the patient was sleepy, with an oxygen saturation of 83% by pulse oximetry. Oxygen saturation improved to 96% while the patient breathed spontaneously aided by jaw thrust and manual CPAP by Mapleson C transport circuit and mask. Encouraged to cough, the patient produced copious, pink, frothy sputum. His chest radiograph in the postanesthesia care unit revealed patchy bilateral infiltrates. Because his oxygen saturation fell to 91% with removal of manual CPAP and 100% oxygen, CPAP mask was instituted.
CPAP was provided by face mask (Respironics BiPAP S/T Ventilatory Support System), with improvement of oxygen saturation to 99% on 10 cm H2 O of CPAP and 60% oxygen. The patient became uncomfortable wearing the CPAP mask, swallowing air, and choking on frothy expectorated sputum. Nasal BiPAP was instituted (Respironics SleepEasy II), which delivered 10 cm H2 O of inspiratory airway pressure alternating with 4 cm H2 O of expiratory airway pressure. The patient tolerated nasal BiPAP well and breathed nasally while expectorating frothy sputum orally. The nasal BiPAP was discontinued after 2 h. The patient was discharged to a day hospital room with an oxygen saturation of 100% on 40% oxygen by face shield. We believe that nasal BiPAP was effective in this case of postobstructive pulmonary edema by providing inspiratory pressure support and positive end-expiratory pressure without interfering with coughing of pulmonary secretions.
J. C. Gerancher, MD
Duke B. Weeks, MD
Department of Anesthesia, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27157-1009