• Virtual Rounds Session 9: Bacterial Endocarditis (Premed Shadowing)

Virtual Rounds Session 9: Bacterial Endocarditis (Premed Shadowing)

Throughout each premed virtual shadowing session, you will actively participate by answering and asking questions about the week’s proposed case. Like an in-person shadowing experience, we strive to stimulate students intellectually and ultimately reaffirm their interest in medicine.

 

Introduction – Infective Bacterial Endocarditis

Infective bacterial endocarditis is an important topic in medicine and needs to be diagnosed quickly in patients to ensure that they have the best outcome. There are multiple etiologies that can cause infective endocarditis, and in the specific case below, we will discuss a case of infective bacterial endocarditis.

Case Highlights 

Mr. M is a 51 yo M with no reported PMH who is presenting to the ED with fevers, chills, and progressively worsening shortness of breath over the past four days. He was seen in the ED two days prior for the same complaint, but left against medical advice (AMA) to use drugs.

He also states that he has been having bilateral lower extremity swelling and intermittent chest tightness.

Of note, while the patient denied past medical history during the interview, he was found to have heart failure (confirmed by labs and ultrasound) as well as bilateral pleural effusions (confirmed by ultrasound and CT scan) during his last ED visit.

Pathology 

What is endocarditis? Endocarditis is defined as inflammation of the endothelium of the heart, heart valves, or both
• This inflammation is caused by damage to the endothelium of the heart and can lead thrombus (clot) formation that can become infected by circulating bacteria

Who tends to get endocarditis? People most at risk have a diseased or damaged heart (congenital heart disease, rheumatic heart disease, bicuspid aortic valve, previous heart infection). Other risk factors include intravenous (IV) drugs use, immunocompromised states (cancer, HIV), and poor oral hygiene

Which part of the heart does it usually involve? The mitral valve is the most commonly affected valve overall, but the tricuspid valve is most commonly affected in IV drug use

How can one diagnose it? The first thing to do is to assess the patient’s vitals. If the patient has a fever, fast heart rate (>100 bpm), or fast breathing rate (>24 breaths/min) and one of the risk factors above, consider endocarditis.

Labs can show elevated white blood cell count as well as elevated inflammatory markers including ESR and CRP. You will want to also draw three sets of blood cultures prior to treatment.

It is important to obtain a transthoracic echocardiogram (ultrasound of the heart) as soon as possible in someone with suspected endocarditis.

To treat bacterial endocarditis, start broad spectrum antibiotics as soon as possible. Treatment options include: ampicillin/ sulbactam, gentamicin, and vancomycin (all IV). This person will need to be admitted to the hospital for at least a few days.

 Take home points

  1. If Infective bacterial endocarditis is suspected, a transthoracic echo (ultrasound of the heart) should be ordered ASAP
  2. Make sure to ask patients with suspected endocarditis about a history of congenital heart disease, recent oral surgeries, and IV drug use
  3. Staph aureus is the most common pathogen in bacterial endocarditis
  4. The mitral valve is the most commonly involved valve in bacterial endocarditis, unless someone uses IV drugs, then the tricuspid valve is the most likely valve

Watch the virtual shadowing session here:

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