Introduction: Sepsis with suspected endocarditis in the setting of DKA, acute pancreatitis, and embolic complications poses a diagnostic challenge when the source of infection is unclear. We present a critically ill patient with metabolic and infectious derangements highlighting MSSA bacteremia with embolic infarcts with no clear infectious source.
Description: A 61-year-old female with no known medical history presented with altered mental status. Labs showed HAGMA, ketosis, hyperglycemia, and elevated lipase. D-dimer was elevated, prompting imaging which revealed subsegmental pulmonary emboli, a splenic infarct, and pancreatitis with reactive duodenitis. She was diagnosed with new-onset T2DM and initiated on insulin infusion for DKA and supportive care for acute pancreatitis. On ICU day 2, her encephalopathy and respiratory fatigue worsened, prompting intubation. Blood cultures from two peripheral sites grew MSSA. MRI brain showed multifocal frontal infarcts. Given the embolic findings and MSSA bacteremia, endocarditis was suspected; however, TEE showed no vegetations. No clear source of bacteremia or emboli was identified. She was started on a 6-week course of cefazolin for possible endocarditis per Duke criteria. Her condition improved: DKA resolved by day 3, extubated on day 5 and repeat blood cultures cleared. A diagnosis of substance use disorder (IV drug use and alcohol) was made later in the hospitalization.
Discussion: Despite a thorough diagnostic workup, this patient’s MSSA bacteremia and embolic complications occurred without a clearly identifiable source. The absence of vegetations on TEE was unexpected, given TEE's high sensitivity. Nonetheless, the clinical scenario fulfilled Duke criteria for possible endocarditis, justifying empiric treatment. A similar case by Aal Yaseen et al. describes disseminated MSSA bacteremia with embolic complications and negative echocardiographic findings. These cases reinforce the principle that imaging limitations should not preclude treatment when clinical suspicion remains high. Given the risk of metastatic complications and high mortality associated with MSSA bacteremia, early recognition and guideline-concordant antibiotic therapy are essential, even without a confirmed source.
