Case series of dermatomyositis complicated by acute respiratory failure requiring intensive care

Introduction

Dermatomyositis (DM) is a rare disorder of variable severity, ranging from mild weakness that is highly responsive to corticosteroid therapy to a relentless downhill course with pulmonary involvement that is unresponsive to all immunosuppressive modalities.

Method

In this retrospective case series, we reviewed the clinical presentation and outcomes of all DM patients who were admitted to the medical intensive care unit (MICU) of a university-affiliated general hospital from 1 January 2000 to 31 December 2004. All had acute respiratory failure requiring mechanical ventilation (MV).

Results

The nine patients had a mean age of 47.6 ± 12.4 (range: 27–66) years. The female to male ratio was 3.5:1. All were diagnosed to have DM before MICU admission with median duration of illness of 8 (range: 3–28) weeks. DM was classified as classical (Peter and Bohan's criteria) in six patients and amyopathic (Sontheimer's criteria) in three. Initial high-resolution computed tomography thorax in eight patients showed pulmonary fibrosis (four patients), interstitial/alveolar changes (two patients), and ground-glass changes (two patients). All patients were negative for anti-Jo1 antibody, and none had an associated malignancy.

The mean PaO₂/FiO₂ was 109.2 ± 40.9 (range: 61.8–181.7) mmHg. The median duration of hospital and MICU stay were 16 (range: 2–38) days and 13 (range: <1 to 37) days, respectively. The median duration of MV was 10 (range: <1 to 37) days.

All chest radiographs showed bilateral lung infiltrates. Broncho-alveolar lavage was performed on six patients, with findings of pneumocystis cariini in one patient and mycobacterium tuberculosis in another. All patients were treated empirically with broad-spectrum antibiotics for pneumonia including cotrimoxazole for Pneumocystis carinii on admission to the MICU. Immunosuppressive therapies in the MICU included high-dose systemic corticosteroids in all, pulse methylprednisolone (five patients), pulse cyclophosphamide (three patients), high-dose intravenous immunoglobulin (one patient) and cyclosporine (two patients). All patients died of respiratory failure with four having hypotension and acute renal failure as contributing causes.

Conclusion

DM with pulmonary involvement that required MV carries an extremely high mortality. Early diagnosis and effective immunosuppressive therapies for lung disease may help to improve outcome in this high-risk group.