Key Points
- Use the highest‑yield diagnostic test early; do not let testing delay time‑critical therapy.
- Set objective targets and reassess frequently.
- Plan definitive source control or disease‑specific therapy when indicated; document follow‑up and patient education.
Algorithm
- Draw cultures; start empiric regimen; apply Duke Criteria.
- Obtain TTE/TEE; screen for emboli; involve cardiothoracic surgery early if indicated.
- Tailor antibiotics to pathogen; plan duration; address source and secondary prevention (dental care).
Clinical Synopsis & Reasoning
Suspect IE with persistent bacteremia, new murmur, or emboli. Obtain three sets of blood cultures before antibiotics when possible, apply Modified Duke Criteria, start empiric IV therapy tailored to native vs prosthetic valve and MRSA risk, and evaluate for surgery when heart failure, uncontrolled infection, or embolic risk is present.
Treatment Strategy & Disposition
Stabilize ABCs. Initiate guideline‑concordant first‑line therapy with precise dosing and continuous monitoring. Escalate to advanced/procedural interventions based on explicit failure criteria. Define ICU, step‑down, and ward disposition triggers; involve specialty teams early.
Epidemiology / Risk Factors
- Risk varies by comorbidity and precipitants; see citations for condition‑specific data.
Investigations
| Test | Role / Rationale | Typical Findings | Notes |
|---|
| Three sets of blood cultures before antibiotics | Diagnosis | Microbiologic confirmation | — |
| TTE then TEE | Imaging | Vegetations, abscess, prosthetic valve assessment | TEE more sensitive |
| Baseline labs and embolic workup (CT/MRI) | Complications | Stroke, splenic/renal emboli | Guide management |
High-Risk & Disposition Triggers
| Trigger | Why it matters | Action |
|---|
| Heart failure due to valve dysfunction | Surgical indication | Urgent surgery evaluation |
| Embolic stroke with large vegetation (>10 mm) | Recurrent emboli risk | Surgery consideration after neuro eval |
| Uncontrolled infection/abscess | Persistent bacteremia | Surgical source control |
| Prosthetic valve or intracardiac device | Complex infection | Cardiothoracic/infectious disease team |
| Fungal IE | Poor medical response | Surgery + antifungals |
Pharmacology
| Medication/Intervention | Mechanism | Onset | Role in Therapy | Limitations |
|---|
| Empiric: Vancomycin + Ceftriaxone (native valve, pending cultures) | Antibiotics | Hours | Cover MRSA/streptococci/enterococci | Adjust per susceptibilities |
| Prosthetic valve: Vancomycin + Gentamicin + Cefepime (or Rifampin per timing) | Broader regimen | Hours | Device/early PVE coverage | Monitor drug levels |
| Definitive tailored therapy for 4–6 weeks | Curative | Weeks | Bactericidal regimen | ID-guided |
Prognosis / Complications
- Outcome depends on timeliness of diagnosis and definitive therapy; monitor for complications.
Patient Education / Counseling
- Provide red‑flag education, adherence guidance, and explicit return precautions; arrange timely specialty follow‑up.
References
- AHA/IDSA infective endocarditis guidelines — Link