SESSION TYPE: Airway Student/Resident Case Report Posters
PRESENTED ON: Tuesday, October 23, 2012 at 01:30 PM - 02:30 PM
INTRODUCTION: The negative pressure pulmonary edema (NPPE) is a known cause of acute respiratory failure requiring mechanical ventilation and supportive care. This is most often seen in post surgical and post general anesthesia patients. Here, we report a case of laryngeal asthma presenting as NPPE.
CASE PRESENTATION: 29 year old female with a history of anxiety and depression presents with shortness of breath for four days with no other symptoms. She has 5 pack year history of smoking. On admission, body temperature was 37.2 C, blood pressure was 150/107 mm Hg and pulse 120. She had tachypnea, expiratory wheezing and occasional stridor. CBC, BMP and ABG are normal. Urine drug screen shows cocaine and Benzodiazepine. Twenty minutes later she had respiratory distress and was found unresponsive. On physical exam, she had diffuse bilateral crackles. Direct laryngoscopy showed inspiratory adduction of anterior 2/3 of vocal cords. She was intubated for airway protection. Chest xray revealed bilateral diffuse patchy interstitial infiltrates. 2D ECHO reveals ejection fraction of 60% with normal findings. Bronchoscopy and CT neck were normal. She gradually improved and extubated successfully after 48 hours.
DISCUSSION: We suspect NPPE as the cause of this patient’s acute respiratory failure. The bilateral diffuse pulmonary infiltrates and rapid resolution are compatible with diagnosis of NPPE, making aspiration pneumonitis less likely. Most common recognized cause of NPPE is emergence from general anesthesia and post-operative extubation. We hypothesize that laryngeal asthma in this patient precipitated NPPE. Laryngeal asthma aka vocal cord dysfunction is the abnormal adduction of true vocal cords during inspiration or expiration, and is seen in female patients with various psychiatric disorders including depression/anxiety. Many are often misdiagnosed as asthma. Diagnosis is by direct laryngoscopic visualization of inspiratory adduction of anterior 2/3 of vocal cords. They usually have normal ABG, PFT’s (except the inspiratory limb of the Flow-volume loop) and negative bronchoprovocation testing.
CONCLUSIONS: The question remains, can laryngeal asthma generate enough negative intrathoracic pressure to cause NPPE and acute respiratory failure? In theory it would be similar mechanism to laryngeal spasm with closure of central airway and inspiratory efforts against a closed glottis creating large negative intra pleural and alveolar pressure.
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DISCLOSURE: The following authors have nothing to disclose: Prasanna Tadi, Arpana Mahalingashetty, Gary Wendell
No Product/Research Disclosure InformationCrozer Chester Medical Center, Upland, PA