Successful use of VV ECMO in managing negative pressure pulmonary edema

Negative pressure pulmonary edema (Review)

Negative pressure pulmonary edema (NPPE) is a complication resulting from acute or chronic upper airway obstruction, often posing challenges in recognition and diagnosis for clinicians. If left untreated, NPPE can lead to hypoxemia, heart failure and even shock. Furthermore, the drug treatment of NPPE remains a subject of controversy. The primary pathophysiological mechanism of NPPE involves the need for high inspiratory pressure to counteract upper airway obstruction, subsequently causing a progressive rise in negative pressure within the pleural cavity. Consequently, this results in increased pulmonary microvascular pressure, leading to the infiltration of pulmonary capillary fluid into the alveoli. NPPE exhibits numerous risk factors and causes, with laryngospasm following anesthesia and extubation being the most prevalent. The diagnosis of NPPE often presents challenges due to confusion with conditions such as gastroesophageal reflux or cardiogenic pulmonary edema, given the similarity in initial factors triggering both diseases. Upper airway patency, positive pressure non-invasive ventilation, supplemental oxygen and re-intubation mechanical ventilation are the foundation of the treatment of NPPE. The present review aims to discuss the etiology, clinical presentation, pathophysiology and management of NPPE.

Negative pressure pulmonary oedema due to rigors and chills associated with liver abscess

A 61-year-old male presented with progressive generalized weakness, myalgia, diaphoresis, fever, episodic chills and rigors that had started 4 days previously. Chest x-ray (CXR) showed overlying curvilinear radio-opacities. Abdominal computed tomography revealed liver and bilateral adrenal lesions. Empiric 7-day intravenous Piperacillin / Tazobactam (Zosyn) was initiated, and he was admitted for sepsis. After an episode of rigors on Day 2, he developed acute hypoxic respiratory failure with inspiratory stridor. CXR revealed new, bilateral airspace disease. Racemic Epinephrine, Solumedrol, Ketorolac (Toradol) and Diphenhydramine were given, and he was transferred to the intensive care unit with presumptive diagnosis of foreign body aspiration or allergic reaction. With each subsequent episode of rigor and chills, he continued developing hypoxic respiratory failure with stridor and an incremental increase in pulmonary oedema on imaging. Pulmonologist concluded it likely secondary to negative pressure pulmonary oedema caused by transient laryngeal dyskinesia induced by the increased work of breathing associated with rigors. Symptoms resolved after the complete course of antibiotics along with supportive therapy.

Extraordinary Delayed-Onset Negative Pressure Pulmonary Hemorrhage Resulting in Cardiac Arrest after General Anesthesia for Vocal Cord Polypectomy

Negative pressure pulmonary edema and hemorrhage are uncommon but potentially life-threatening complications associated with general anesthesia. Postoperative negative pressure pulmonary edema usually occurs immediately after surgery, and delayed-onset cases occurring more than 1 hour after surgery have rarely been reported. A 37-year-old woman with bronchial asthma underwent vocal cord polypectomy under general anesthesia in another hospital and experienced cardiac arrest due to a negative pressure pulmonary hemorrhage occurring 3 hours and 30 minutes after surgery. She was successfully treated with venoarterial extracorporeal membrane oxygenation and completely recovered without any complications. Extraordinary delayed-onset negative pressure pulmonary hemorrhage occurring more than three hours after surgery has rarely been reported. This case may indicate the need for more careful observation of patients following surgery.