Extracorporeal Membrane Oxygenation in Severe Acute Eosinophilic Pneumonia

Idiopathic Chronic Eosinophilic Pneumonia Evolving to Pulmonary Fibrosis: A Retrospective Analysis

BACKGROUND

Patients with idiopathic chronic eosinophilic pneumonia (ICEP) may have pulmonary fibrosis.

OBJECTIVES

To investigate the predictors of pulmonary fibrosis in ICEP, to describe the timeline of pulmonary fibrosis after ICEP diagnosis, and to detail the radiologic pattern of fibrosis.

METHODS

A retrospective computer-assisted search was performed to identify patients with ICEP seen at Mayo Clinic in Rochester, Minnesota, from January 1, 1997, through September 1, 2019. Patients with follow-up chest computed tomography (CT) beyond 12 months after the ICEP diagnosis were included in the study. Demographic, clinical, radiologic, and histopathologic characteristics were analyzed. Proportional hazards regression was used to assess the predictors of pulmonary fibrosis.

RESULTS

We identified 62 patients (mean [SD] age at ICEP diagnosis, 60 [13] years; female sex, 37 [60%]). Cough (87%) and shortness of breath (85%) were the most common presenting symptoms. Of patients, 27 (44%) had a history of smoking and 27 (44%) had a history of asthma. During follow-up, 23 patients (37%) had CT evidence of pulmonary fibrosis, of whom 16 patients (70%) had a CT pattern inconsistent with usual interstitial pneumonia. In 29% of the patients, the CT evidence of pulmonary fibrosis developed within 2 years after ICEP. Age and male sex were predictors of pulmonary fibrosis. Of note, a history of asthma decreased the likelihood of pulmonary fibrosis.

CONCLUSIONS

Development of pulmonary fibro-sis is not uncommon in patients with ICEP, especially older men, and is associated with increased risk of death.

[Case report of severe acute eosinophilic pneumonia induced by amoxicillin]

INTRODUCTION

Acute eosinophilic pneumonia (AEP) is a rare and potentially severe disorder, characterized by an acute febrile respiratory illness with diffuse pulmonary infiltrates, pleural effusions and an eosinophilic alveolitis identified on broncho-alveolar lavage or lung biopsy. The condition can be idiopathic, or induced by the inhalation of toxic substances, by infections or by medications. The condition tends to respond rapidly to treatment with systemic steroids.

CASE REPORT

We report the case of a 16-year old patient who presented severe acute interstitial pneumonia with eosinophilia (1.17g/L). They had taken a seven-day course of amoxicillin treatment two weeks previously for a dental abscess. The patient initially required respiratory support by mechanical ventilation followed by extracorporeal membrane oxygenation due to severe refractory hypoxemia. After exhaustive investigation a diagnosis of amoxicillin-induced acute eosinophilic pneumonia was made. After steroid treatment was initiated the clinical response was rapidly favorable and remission was achieved. The patient has been advised to avoid beta lactam antibiotics for life.

CONCLUSION

This case illustrates a rare case of severe acute eosinophilic pneumonia induced by amoxicillin.

Idiopathic acute eosinophilic pneumonia: A rare cause of hypoxic respiratory failure

Idiopathic Acute Eosinophilic Pneumonia (IAEP) is a life-threatening cause of hypoxic respiratory failure. IAEP is challenging to diagnose as it may mimic infectious pneumonia or acute respiratory distress syndrome. Distinguishing IAEP from these alternatives is important; the mainstay of treatment for IAEP is corticosteroids, a therapy which might not otherwise be indicated. Patients treated appropriately usually experience a full recovery. In this case report we describe the presentation, evaluation, and management of a 19-year old male who presented to the emergency department (ED) in respiratory failure from IAEP. The patient was a military trainee who recently moved to the United States from Saudi Arabia. He also recently began smoking cigarettes for the first time, a known risk factor for IAEP. Upon initial presentation, the patient was in respiratory distress and had an oxygen saturation of 82% on room air. His ED diagnostic workup included chest X-ray showing diffuse interstitial thickening and chest computed tomography that demonstrated diffuse nodular opacification of pulmonary parenchyma. The patient was admitted to the intensive care unit (ICU) where bronchoscopy yielded cytology with 30% eosinophilia. The patient ultimately required 3 days of extra corporeal membrane oxygenation (ECMO) due to worsening hypoxic respiratory failure. After both intravenous and outpatient oral steroid treatments, the patient went on to have a full recovery with no ongoing respiratory issues. To our knowledge, this is the first case of IAEP requiring ECMO reported in the emergency medicine literature.