(1140) Human Metapneumovirus (hMPV) Leading to Acute Respiratory Distress Syndrome (ARDS)

Introduction: Respiratory viruses can cause severe community-acquired pneumonia (CAP) leading to ARDS. Management for viral pneumonia has been largely supportive, but with the coronavirus disease in 2019, corticosteroids have increasingly been used as an adjuvant therapy for epidemic viral pneumonias. The efficacy and safety of corticosteroid therapy in viral respiratory infections remain controversial. This case demonstrates the effectiveness of corticosteroid treatment in viral CAP secondary to hMPV associated with ARDS.

Description: A 65-year-old male with a history of hypertension, diabetes, and tobacco use presented with dyspnea and cough. He was hypoxic to 60% on room air and was placed on Bilevel for work of breathing. A chest X-ray showed bilateral patchy opacities and CT chest revealed multifocal ground-glass and nodular opacities diffusely. A respiratory panel was positive for hMPV A+B. Bacterial workup, procalcitonin level (0.15ng/mL), and sputum culture were negative. Initial arterial blood gas showed pH 7.39/pCO2 46.5/pO2 65.8/HCO3 28.7, and FiO2 60%. His P/F ratio was 109, consistent with moderate ARDS. Consequently, he was initiated on dexamethasone 20 mg IV daily. The patient alternated between Bilevel and high-flow nasal cannula until day 7, when he was successfully weaned to nasal cannula. He received a total of 5 days of high-dose dexamethasone and showed marked recovery. He was downgraded on day 8 and discharged on day 10 on room air.

Discussion: hMPV is a common respiratory virus, but it rarely leads to ARDS. One case series reported that out of 128 adults hospitalized with hMPV, 14.8% developed ARDS. Another study of 402 patients with hMPV found that 33% required ICU admission, with an ICU mortality rate as high as 23%; therefore early diagnosis and treatment are integral. This case highlights the early use of dexamethasone in the setting of hMPV-induced ARDS, resulting in rapid recovery and eventual discharge. This case supports the potential role of corticosteroids in treating severe viral pneumonia, particularly in the context of ARDS. The patient's marked improvement underscores the potential benefits of corticosteroids in managing viral ARDS, though further studies are necessary to fully understand their efficacy and safety in viral respiratory diseases other than Covid-19.