Title : Sepsis-induced gastrointestinal dysfunction- An atypical initial presentation of infective endocarditis
Abstract:
Introduction: Infective endocarditis (IE) is a life-threatening condition with mortality approaching 30% with highly variable presentation. Although fever and cardiac murmurs are classic, their absence does not exclude IE. Among persons who inject drugs, right-sided IE is common and most frequently caused by Staphylococcus aureus. We report a case of MRSA tricuspid valve endocarditis presenting with acute gastrointestinal symptoms and refractory septic shock, highlighting sepsis-induced gut dysfunction as an underrecognized presentation.
Case Report: A 35-year-old male with a history of intravenous heroin use and opioid use disorder presented with multiple episodes of nonbloody, nonmucoid diarrhea, associated with epigastric and right upper quadrant abdominal pain, without prior antibiotic exposure, with on & off episodes of chills and progressive right-sided pleuritic chest pain. He denied hematochezia, melena, vomiting, recent travel, sick contacts, animal exposure. Physical examination revealed multiple needle track marks, hepatosplenomegaly with right upper quadrant tenderness, pulmonary crackles, and altered mental status with confusion, without focal deficits. No peripheral stigmata of infective endocarditis or cardiac murmur were noted. On presentation, he has a mean arterial pressure of 45 mmHg, tachycardia, and tachypnea despite fluid resuscitation, requiring maximal doses of norepinephrine, phenylephrine, and vasopressin. He remained vasopressor-dependent for five days before achieving hemodynamic stability. Labs demonstrated leukemoid reaction (WBC 40,600/μL), thrombocytopenia (64,000/μL), acute kidney injury (creatinine 2.6 mg/dL; BUN 111 mg/dL), hyponatremia (128 mEq/L), and lactic acidosis (5.2 mmol/L). Inflammatory markers were markedly elevated, with associated transaminitis, hypoalbuminemia, and sepsis-induced coagulopathy. Four sets of blood cultures obtained prior to antibiotic initiation grew methicillin-resistant Staphylococcus aureus (MRSA). Nasal and sputum cultures were also positive for MRSA, while urine cultures were negative. Stool studies suggestive of secretory diarrhea. Noncontrast CT imaging of the chest and abdomen revealed numerous, subpleural and intra parenchymal cavitating pulmonary nodules consistent with septic emboli, hepatosplenomegaly, without bowel ischemia or intra-abdominal abscess. CT angiography could not be performed due to renal dysfunction. Transthoracic echocardiography was unrevealing; transesophageal echocardiography revealed a large mobile tricuspid valve vegetation measuring 2.2 × 2.4 cm with moderate tricuspid regurgitation, confirming right-sided infective endocarditis. The patient met Modified Duke Criteria for definite IE and was treated with intravenous vancomycin and gentamicin, with subsequent clearance of bacteremia, improving urine output, and resolution of shock.
Discussion & Conclusion: Gastrointestinal involvement in IE occurs through embolic phenomena, immune-mediated vasculitis, metastatic infection, or sepsis-induced gut dysfunction. Embolic events can cause mesenteric ischemia, ileus, or intra-abdominal abscesses, while immune complex deposition may result in gastrointestinal vasculitis. In this case, diarrhea preceding antibiotic exposure, absence of focal bowel pathology on imaging, and prolonged vasopressor-dependent septic shock with secretory diarrhea strongly support sepsis-induced gut dysfunction as the primary mechanism. Severe sepsis leads to splanchnic hypoperfusion, microcirculatory dysfunction, epithelial injury, immune dysregulation, increased intestinal permeability (leaky gut), and intestinal dysbiosis, with translocation of inflammatory mediators manifesting clinically as diarrhea. Gastrointestinal-dominant presentations of IE remain uncommon and underrecognized. Heightened clinical suspicion, early echocardiography, and recognition of sepsis-induced gut dysfunction are essential to avoid diagnostic delay and optimize outcomes in high-risk patients.
