NONCARDIOGENIC NEGATIVE PRESSURE FLASH PULMONARY EDEMA IN A YOUNG ADULT PATIENT AFTER LARYNGOSPASM: A CASE REPORT

Abstract

TOPIC: Respiratory Care TYPE: Medical Student/Resident Case Reports INTRODUCTION: Laryngospasm is a sudden involuntary muscular spasm of the vocal cords, it can lead to cardiac arrest due to hypoxia if not timely treated. Negative pressure flash pulmonary edema (NPPE) is a rare complication secondary to laryngospasm in adults after the acute treatment, which results from forceful inspiration against blocked airways and the resulting high negative pressure in alveoli, causing fluids to flux to the interstitial and alveolar spaces. Healthy individuals are more prone for NPPE due to the strength to induce higher intrathoracic negative pressure to challenge an obstruction. This case illustrates a young adult developed postoperative laryngospasm resulting in a flash NPPE. CASE PRESENTATION: A 40 year-old male, with a history of type 1 diabetes and recent mild COVID-19 Pneumonia was admitted for minor surgery. Pre-operative assessment concluded with ASA class 2, and moderate functional status. He has no history of anesthetic complications. Surgery was done under general anesthesia with a laryngeal mask (LMA). During Recovery after the LMA was removed, he started to desaturate, with audible stridor, cyanosis and retractions. High flow oxygen mask and IV Succinylcholine were given with no response. He was immediately intubated, ET tube suctioning showed large amounts of frothy pink secretions, his saturation had improved immediately to 100% with manual positive pressure ventilation. Sustained closure of the vocal cords was observed during intubation. However, his oxygen requirement didn't improve during the first day, and he failed a spontaneous breathing trial(SBT). Chest radiograph showed diffuse haziness suggestive of pulmonary edema. Chest CT showed pulmonary edema more significant in the dependent areas with atelectasis, it also showed diffuse ground glass opacities of recent COVID-19 pneumonia. He was started on parenteral furosemide, negative fluid balance of five liters was achieved in 24 hours. Surprisingly, his breathing effort was significantly improving with fluid elimination, oxygen requirements was weaned to minimum, passed SBT on CPAP mode, and later extubated. Patient was discharged with no evidence persistent airways pathology. DISCUSSION: Laryngospasm is less common in adults, usually it results from physical manipulation of the airways. Forceful inspiration against obstructed airways results in negative intrathoracic pressure above physiological limit, which disrupts the balance of hydrostatic pressures of alveoli, interstitium and the capillaries, leading to fluid accumulation in the alveolar space, it manifest clinically with desaturation, and diffuse opacities on imaging. High negative pressure increases the permeability as well, which drive the RBCs to extravasate and manifest as bloody mucous secretions. CONCLUSIONS: Fortunately, if NPPE gets timely recognized, patients respond magically to treatment with higher positive pressure ventilation and diuretics. REFERENCE #1: Bhattacharya M, Kallet RH, Ware LB, Matthay MA. Negative-Pressure Pulmonary Edema. Chest. 2016 Oct;150(4):927-933. doi: 10.1016/j.chest.2016.03.043. Epub 2016 Apr 8. PMID: 27063348. DISCLOSURES: No relevant relationships by Hasan Abuamsha, source=Web Response No relevant relationships by Hadeel Abuteer, source=Web Response No relevant relationships by Abdul Rahman Al Armashi, source=Web Response No relevant relationships by Isaac Alsallamin, source=Web Response No relevant relationships by Ameed Bawwab, source=Web Response No relevant relationships by Faris Hammad, source=Web Response No relevant relationships by Seshma Ramsawak, source=Web Response No relevant relationships by Francisco Somoza-Cano, source=Web Response