P3.273: From Shoulder Pain to Respiratory Failure: Severe Osteomyelitis Presenting as ARDS

Introduction: Acute respiratory distress syndrome (ARDS) is a rare but severe complication of osteomyelitis, typically arising in the context of sepsis. Pediatric ARDS is most often secondary to pneumonia, viral infections, trauma and near-drowning events with musculoskeletal infections rarely reported as a trigger in the literature. We report a case of shoulder osteomyelitis complicated by Pediatric ARDS.

Case Description: A previously healthy, fully immunized 15-year-old male presented with right shoulder pain following a wrestling injury 6 days prior. Due to the severity of pain, he was admitted for further evaluation and analgesia. MRI revealed abnormal marrow signal and subperiosteal hematoma in the proximal right humerus with associated soft tissue and muscle edema. The patient subsequently developed fever, hypoxemia, hemoptysis, and respiratory distress. Chest x-ray demonstrated bilateral pulmonary opacities, prompting initiation of empiric antibiotic therapy and blood culture. He was transferred to a tertiary Pediatric Intensive Care Unit (PICU) for ARDS management. Blood cultures grew methicillin-sensitive Staphylococcus aureus (MSSA). The patient remained febrile with worsening shoulder pain. Repeat MRI performed showed right humerus myositis/osteomyelitis with small periosteal fluid, subcutaneous edema, and elbow effusion. Due to worsening respiratory status, the patient required mechanical ventilation via endotracheal intubation. Given persistent bacteremia despite appropriate antimicrobial treatment, worsening respiratory failure with escalating ventilator settings, and potential need for extracorporeal membrane oxygenation (ECMO), orthopedic surgical debridement was performed for better source control. Surgical exploration revealed purulent material, and cultures grew MSSA, confirming the diagnosis of acute hematogenous osteomyelitis. Clinical improvement was observed only after multiple debridement procedures, including irrigation of bone, muscle, and fascia. The patient also developed septic shock, multiple organ failure, and acute kidney injury requiring continuous renal replacement therapy (CRRT). However, a need for ECMO was averted because of timely surgical intervention for source control and targeted antimicrobial treatment. The patient required CRRT for a total of 30 days, had a PICU stay of 69 days, contributing to a total hospital stay of 100 days.

Discussion: Infectious etiologies should be promptly identified and managed in patients with ARDS. Although osteomyelitis is an uncommon cause, early recognition is critical. Initial deep tissue swelling can obscure underlying bone involvement, delaying diagnosis. In this case, clinical improvement was achieved only after surgical intervention. A high index of suspicion for osteomyelitis in musculoskeletal pain is essential to prevent severe complications such as ARDS and multi-organ failure.

Conclusion: This case underscores a rare but critical complication of osteomyelitis and highlights the necessity of repeat imaging and surgical interventions when clinical improvement is unexpectedly delayed.