B52-42 Not Just Another Crisis Severe Atypical Acute Chest Syndrome

Introduction Acute chest syndrome (ACS) is a leading cause of morbidity and mortality in patients with sickle cell disease (SCD). Approximately 30-50% of patients with SCD will experience at least one episode of ACS during their lifetime, and it accounts for 20-25% of all SCD related deaths. Classically, ACS is defined as the presence of a new pulmonary infiltrate on chest imaging accompanied by at least one manifestation such as cough, fever, chest pain, tachypnea, dyspnea, sputum production, or new onset hypoxia. Viral respiratory infections, including SARS-CoV-2, are well recognized precipitants of ACS. However, atypical cases may initially lack radiographic infiltrates, leading to diagnostic uncertainty and delayed intervention. We present a case of severe ACS in a young adult with SCD and COVID-19. Case Presentation A 23-year-old male with homozygous SCD presented with generalized malaise and worsening musculoskeletal pain unresponsive to home analgesics. On arrival, oxygen saturation was 92% on room air. Laboratory studies revealed leukocytosis, macrocytic anemia (Hgb 9.7 g/dL), mild hyperbilirubinemia (1.7 mg/dL), and a positive SARS-CoV-2 PCR. Arterial blood gases showed mild hypoxemia. The patient was admitted for vaso-occlusive crisis secondary to COVID-19 and managed with intravenous fluids, multimodal analgesia, and incentive spirometry. Despite these measures, he developed persistent fever, tachycardia, and worsening hypoxemia. Chest X-ray and CT scans repeatedly demonstrated only bibasilar atelectasis, without new infiltrates. Infectious Diseases initiated Remdesivir therapy. By hospital day two, oxygen requirements increased, and by day three his hemoglobin dropped more than 1 g/dL from baseline, prompting transfusion. Clinical deterioration progressed to acute hypoxemic respiratory failure requiring intubation and ICU transfer. Given high suspicion for evolving ACS despite negative imaging, urgent multiple exchange transfusions were performed. Over the following days, oxygenation and hemodynamics improved, allowing successful extubation and recovery. Discussion This case underscores an atypical presentation of ACS precipitated by COVID-19, where disease severity was disproportionate to radiologic findings. Conventional management and simple transfusion were insufficient; marked clinical improvement occurred only after exchange transfusion, reaffirming its role as the gold standard for severe ACS. Conclusion Timely recognition of ACS is crucial, even when imaging lacks the classic infiltrates. COVID-19 may induce rapidly progressive ACS with minimal or absent radiographic changes. A high index of suspicion should be maintained, with prompt escalation to exchange transfusion in the setting of worsening hypoxemia or ventilatory failure, as early intervention can be life saving. This abstract is funded by: None