Paradoxical Acute Hypoxemic Deterioration During Treatment of Bilateral Bronchopneumonia: A Case Report

Community-acquired pneumonia may occasionally be associated with unexpected respiratory deterioration despite apparent clinical, laboratory, and radiological improvement. We report a case of a previously healthy adult male who presented with progressive dyspnea, persistent cough, generalized weakness, malaise, and low-grade fever. Initial chest radiography showed no significant abnormalities despite marked respiratory symptoms, whereas chest computed tomography revealed bilateral bronchopneumonia with multiple centrilobular nodules and patchy ground-glass opacities. The patient was treated with intravenous meropenem, systemic corticosteroids, inhaled therapy, supplemental oxygen, and supportive care, with gradual improvement in inflammatory markers. On hospital day three, however, he developed sudden severe hypoxemic respiratory failure shortly after antimicrobial administration, requiring intensive care unit admission and high-flow nasal cannula oxygen therapy. Urgent CT pulmonary angiography excluded pulmonary embolism, follow-up imaging demonstrated partial regression of the pulmonary infiltrates, and cardiological evaluation showed no evidence of acute cardiac pathology. Meropenem was replaced with levofloxacin because a drug-related reaction could not be completely excluded. The patient's respiratory status subsequently improved rapidly with supportive treatment, and he was discharged without residual respiratory insufficiency. This case demonstrates that severe transient hypoxemic deterioration may occur during apparently successful treatment of bilateral bronchopneumonia and emphasizes the importance of promptly excluding pulmonary embolism, acute cardiac disease, drug-related reactions, and other potentially life-threatening causes of respiratory worsening.