Rheumatic Fever: Etiology, Diagnostic Criteria, Complications, and Treatment Guide

Rheumatic Fever: Etiology, Diagnostic Criteria, Complications, and Treatment Guide

Question. Write a short note on prophylaxis for infective endocarditis.
Answer.

Sub-acute bacterial endocarditis is defied as infection and inflammation of the inner lining of the heart, including heart valves.
It also includes infection at the site congenital heart anomaly.

Clinical Manifestations of Infective Endocarditis.

1. General: Presence of nausea, fever, anorexia, weight loss, night sweats, and weakness.
2. Cardiovascular system: Tachycardia, cardiac murmur, conduction defect, and cardiac failure.
3. Blood vessels: Loss of peripheral pulse.
4. Central nervous system: Headache, hemiplegia or monoplegia, and toxic encephalopathy.
5. Lungs: Pleuritic pain and hemoptysis. Nails: Osler’s nodes, clubbing of fingers, and splinter hemorrhage.
6. Skin: Purpuric spots and petechial hemorrhage.
7. Eyes: Roth’s spot and subconjunctival hemorrhage.
8. Kidney: Hematuria and glomerulonephritis
9. Spleen: Splenomegaly is present
10. Blood: Anemia is present

Pathogenesisof  infective endocarditis.

Investigations of infective endocarditis.

1. Blood culture: In the absence of recent or concurrent antibiotic therapy, the fist 3 random blood cultures are positive in most patients, and blood culture is positive by the third day in 90%.
2. Urine: Microscopic hematuria is the most common fiding.
Slight albuminuria and hyaline and granular casts also found.
3. Hematology: Normocytic normochromic anemia, usually mild. May be raised ESR and raised C­reactive protein.
4. Chest radiograph: May be diagnostic in right sided endocarditis, with multiple shadows visible due to an embolic pneumonia.
5. ECG: Myocardial infarction seen on ECG may be due coronary embolism, and a conduction defect may be due to development of an aortic root abscess.
6. Echocardiography: Higher sensitivity in identifying vegetation with transesophageal echocardiography as compared to transthoracic echocardiography.

1. Vegetations: An echodense structure attched to the valve or its supporting structures, or lying in the track of a turbulent jet, which is irregular in shape.
2. Leaflt perforation is best seen as regurgitant jet on color flw mapping.
3. Annular and periprosthetic echolucent spaces (abscesses) and fitula formation.

7. Chest X-ray: Shows evidence of cardiomegaly and heart failure.

Management infective endocarditis.

Management is divided into three parts:

1. Treatment during disease process
2. Prophylaxis
3. Indication for cardiac surgery.

Treatment during disease Process infective endocarditis.

1. It is mainly antimicrobial treatment. Along with source of infection symptoms are removed as soon as possible.
2. Antibiotics should preferably be bactericidal.
3. Antibiotics should be administered parenterally to achieve high serum concentration since the vegetation is avascular.
4. Therapy is generally of prolonged duration.
5. Selection of antibiotics should be based on culture report and minimum inhibitory concentration (MIC) values.
6. Empirical therapy may be initiated in acute severe cases after drawing blood samples for culture.
   The antibiotics are later changed based on sensitivity reports, if necessary.
7. Treatment of infective endocarditis should be prompt and adequate.
   The list of antibiotics commonly used, their dosage and indications are given below in table.

Prophylaxis against Infective endocarditis

Patients with valvular and congenital heart disease who are at high or moderate risk of endocarditis should receiveprophylactic antibiotics before undergoing any procedure which may cause bacteremia.

Antibiotic regimen for prophylaxis of endocarditis in adults at moderate or high­risk is as follows:

1. Oral cavity, respiratory tract, or esophageal procedures (in patients at high­risk, administer a half dose after the initial dose).

1. Standard regimen: Amoxicillin 2.0 g oral 1 hour before procedure.
2. Inability to take oral medication of standard regimen:
   Ampicillin 2.0 g IV or IM within 30 min of procedure.
3. If patient is allergic to penicillin:
   Or
   Cephalexin or cefadroxil 2 g orally 1 hour before procedure
   O
   Clindamycin 600 mg oral l hour before procedure
4. If patient is allergic to penicillin and is unable to take oral medication
   Clindamycin 600 mg I.V. 30 min before procedure.
   Or
   Cefazolin 1.0 g I.V. or IM 30 min before procedure.

2. Genitourinary and gastrointestinal tract procedures:

1. In high risk patients: Ampicillin 2g IM or IV + gentamycin 1.5 mg/kg IV or IM within 30 min of starting the procedure followed by ampicillin
2. In high-risk patients allergic to penicillin: Vanacomycin 1g IV over 1 to 2 hour + gentamycin 1.5 mg/kg IV or IM combination is given within 30 min of starting the procedure.
3. In moderate risk patients: Amoxicillin 2.0 g oral 1 hour before procedure Or ampicillin or amoxicillin 2.0 g IV or IM within 30 min of procedure.
4. In moderate riskpatients allergic to penicillin: Vancomycin 1g IV over 1 to 2 hours completed within 30 min of starting procedure.

Indication for cardiac surgery

1. Heart failure due to valve damage
2. Failure of antibiotic therapy, i.e. in fungal endocarditis
3. Large vegetation on left sided heart valves with evidence or high­risk of systemic emboli.
4. Abscess formation