Acute interstitial pneumonia-Hamman-Rich syndrome: clinical characteristics and diagnostic and therapeutic considerations.

Background: Acute interstitial pneumonia is a rapidly progressive disease frequently leading to respiratory failure and mechanical ventilation. The prognosis is usually poor despite aggressive diagnostic and treatment efforts.

Methods: In this retrospective cohort survey, we enrolled patients with hypoxemic respiratory failure who met predefined criteria of acute idiopathic interstitial pneumonia. Patients' records, radiologic studies, and pathologic specimens were reviewed. All data were recorded in each patient's study file and subsequently analyzed.

Results: Our cohort consisted of 5 men and 4 women with a mean age of 69.4 yr (55-80 yr). The chest radiograph in all patients progressed to diffuse bilateral infiltrates over a 12-day course. All nine patients had histological proof of diffuse alveolar damage consistent with acute interstitial pneumonia, obtained by either transbronchial biopsy or open lung biopsy. All patients required admission to the medical intensive care unit and mechanical ventilation. The mortality rate was 100%, and patients died within 5-26 days of their admission to the unit.

Conclusions: Acute interstitial pneumonia (Hamman-Rich syndrome) is an idiopathic, rapidly progressive and, at times, fatal form of interstitial lung disease. A transbronchial biopsy is a logical first diagnostic step, to be followed by an open lung biopsy, if necessary. Response to corticosteroids in our series was minimal. In patients who fail to respond to conventional therapy and are otherwise appropriate candidates, lung transplantation may be considered as an additional alternative.