CORTICOSTEROIDS IN ACUTE RESPIRATORY DISTRESS SYNDROME SECONDARY TO OVERWHELMING PULMONARY BLASTOMYCOSIS

Abstract

INTRODUCTION: Pulmonary blastomycosis resulting in acute respiratory distress syndrome (ARDS) has a very high mortality in spite of appropriate treatment with anti-fungals. Case reports utilizing adjunctive corticosteroids in ARDS due to blastomycosis suggest benefit. We present a case of ARDS due to blastomycosis treated with corticosteroids early in the disease course resulting in rapid improvement. CASE PRESENTATION: A 19 year old female, resident of Indiana was transferred to our tertiary care center for evaluation of dyspnea and bilateral pulmonary infiltrates. She reported fevers, dyspnea and cough for 3 weeks. She was admitted to a local hospital and was treated with ceftriaxone and azithromycin but continued to worsen. As a result, the antibiotic coverage was changed to piperacillintazobactam, trimethoprim-sulfamethoxazole, linezolid and itraconazole. CT scan of the chest showed diffuse bilateral infiltrates. A bronchoscopy with bronchoalveolar lavage was non-diagnostic. She continued to deteriorate with increasing oxygen requirements. In our facility, a CT guided fine needle aspiration of left lower lobe infiltrates was performed which showed multiple broad-based budding yeast, consistent with Blastomyces dermatitidis. Because of her increasing oxygen requirements and worsening lung infiltrates she was intubated and mechanically ventilated. A diagnosis of ARDS was made, based on bilateral pulmonary infiltrates and a PaO2/FiO2 ratio of 156. Low lung compliance required low tidal volume per ARDS.net protocols. She was started on methylprednisolone (50 mg IV q6hours) and liposomal amphotericin B (520 mg/day). Her oxygenation and lung mechanics improved dramatically and she was extubated after 4 days of mechanical ventilation. She continued to improve, steroids were tapered, amphotericin was switched to oral itraconazole, and she was discharged to home one week later. DISCUSSIONS: Acute respiratory distress syndrome is an infrequent manifestation of blastomycosis infection. It has been associated with high mortality rates reaching 89%, even with appropriate antifungal therapy (1). According to the Infectious Diseases Society of America guidelines, Amphotericin B is the treatment of choice for severe diffuse pulmonary blastomycosis. Some mycologists advocate the additional use of corticosteroids in cases of ARDS secondary to blastomycosis. It has been postulated in a prior report (2) that blastmycosis induces a hyperinflammation syndrome and that adjunctive steroid therapy will reduce this inflammatory response analogous to that seen in Pneumocystis jiroveci pneumonia. In that report, good outcomes were demonstrated for two patients with severe ARDS secondary to blastmycosis who were treated with corticosteroids. We elected to add corticosteroids early in the disease course in an attempt to curb the extent of hyperinflammation associated with severe pulmonary blastomycosis. CONCLUSION: ARDS secondary to blastomycosis carries mortality approaching 90%. The role of corticosteroids is still uncertain in the treatment algorithm of ARDS in general, but there are certain subgroups where corticosteroids are of definite benefit. Based on our report, ARDS induced by blastomycosis may be one of them.