David Carr discusses his top 10 pearls on endocarditis and blood culture interpretation in this Carr’s Cases Best Case Ever on EM Cases – Endocarditis and Blood Culture Interpretation.

Published February 2015

Pearls in the Diagnosis of Endocarditis and Blood Culture Interpretation

Pearl 1. Even though we were taught about Janeway lesions and Osler’s nodes in medical school, the reality is that these peripheral manifestations of endocarditis occur in only about 10% of patients.  Listening for heart murmurs which are present in about 90% of patients with endocarditis is one of the most important physical exam maneuvers in patients who present with fever NYD.

Pearl 2. Look at patients’ teeth who present with fever NYD. If they appear to have poor dental hygiene, think about the possibility of endocarditis.

Pearl 3. Fifteen percent of IV drug users who present to the ED with fever will have endocarditis, so any IV drug user with fever should make you worry about the possibility of endocarditis.

Pearl 4. Endocarditis should be on your radar for any patient with valvular heart disease who presents to the ED whether they are febrile or not.

Pearl 5. Always do 2 or 3 sets of blood cultures from 2 or 3 sites on patients in whom you suspect endocarditis. Drawing a single blood culture is much more likely to lead to a missed diagnosis.

Pearl 6. A Coag Negative Staph Aureus positive blood culture in a patient with valvular disease is endocarditis until proven otherwise, even though the majority of Coag Negative Staph Aureus positive blood cultures are contaminants.

Pearl 7. A blood culture positive for a particular type of Coag Negative Staph Aureus called SLUG (Staphylococus lugdunensis) should raise the possibility of endocarditis even in patients without valvular heart disease.

Pearl 8. A urine culture that is positive for Staph Aureus which is not a common bacteria found in UTIs, should raise the possibility of a more serious systemic infection such as endocarditis.

Pearl 9. Empiric treatment with antibiotics for patients suspected of endocarditis can usually wait until consultation with an infectious disease specialist as the majority of patients with endocarditis will not present in severe sepsis or septic shock.

Pearl 10. Point of Care Ultrasound (POCUS), while far from a definitive test for the detection of vegetations associated with endocarditis, if positive for vegetations, can help increase the suspicion for endocarditis in the ED.


AHA Guidelines on Infective Endocarditis in Adults: Diagnosis, Antimicrobial Therapy, and Management of Complications


More FOAMed Resources on Endocarditis

David Carr on EMCrit


Dr. Helman and Dr. Carr have no conflicts of interest to declare