| ID | 65 |
|---|---|
| Name | INFECTIVE ENDOCARDITIS |
| Cause | |
| Signs Symptoms | |
| Diagnosis | Diagnosis: A. History B. Clinical features. C. Investigations. |
| Investigations | Investigations: 1. Blood counts & chemistry: - Hb%- decreased usually. - ESR- increased usually. - C-reactive protein- increased. 2. Blood culture: 3-5 samples of blood cultures should be taken 1 hours interval. The first two specimens will detect bacteraemia in 90% of culture-positive cases. Gram-negative bacteria (HACEK group) are slow-growing fastidious organisms, that are only revealed after prolonged culture and may be resistant to penicillin. 3. ECG: To see any conduction defect (e.g development of AV block), or occasionally infarction due to emboli, or other findings (if any). 4. Echocardiography: To detect the progress of vegetation, valve damage, or abscess formation. 5. CXR: To see any evidence of cardiac failure and cardiomegaly. |
| Management | Management:1-2 A. Antimicrobial treatment: The best way to start antimicrobial treatment according to sensitivity. But empiric regimens for endocarditis while culture results are pending or not available should include agents active against common pathogenic organisms (staphylococci, streptococci and enterococci). The empiric regimens depend on the mode of presentation, the suspected organism, and whether the patient has a prosthetic valve or penicillin allergy. Such regimens include- According to Davidson’s 20102 If presentation is acute- Flucloxacillin 2gm 4 hourly (< 85kg 6 hourly) i.v for 4 weeks (6 weeks for prosthetic valve). Plus Gentamicin Img/kg 8 to 12 hourly i.v for 2 weeks. If presentation is subacute or indolent- Inj. penicillin G (benzyl penicillin) 1.2gm 4 hourly for 4 weeks. (In case of penicillin allergy, vancomycin 15mg/kg 12 hourly i.v for 4 weeks, may be used). Plus Gentamicin Img/kg 8 to 12 hourly i.v for 2 weeks. According to CMDT 2010' Irrespective of presentation and suspected organism, empiric regimen can be given as following for appropriate coverage- Vancomycinlgm 12 hourly i.v for 4 weeks. Plus Ceftriaxone 2gm once daily i.v or i.m for 4 weeks. When culture results are available treatement should be given according to sensitivity. 1. Streptococcus viridans & bovis- Penicillin G (benzyl penicillin) 2-3 million units i.v 4 hourly for 4 1 weeks and gentamicin Img/kg every 8 hours for 2 weeks for susceptible organisms (or 4 weeks for others). Or, Ceftriaxone 2gm once daily i.v or i.m for 4 weeks. Or, For the Penicillin-allergic patients, Vancomycin 15mg/kg i.v 12 hourly for 4 weeks. 2. Other streptococcal strains- Penicllin G (benzyl penicillin) 2-3 million units i.v 4 hourly for 4-6 weeks. In case of streptococcal strains with increasing chance of penicillin-resistance, gentamicin may be given Img/kg i.v 8 hourly with penicillin for the first 2 weeks. Or, Ceftriaxone 2gm once daily i.v or i.m for 4-6 weeks. Or, For the Penicillin-allergic patients, Vancomycin 15mg/kg i.v 12 hourly for 4-6 weeks. 3. Enterococci- Ampicillin or Amoxicillin 2gm i.v 4 hourly for 4 weeks. Plus, Gentamicin 80mg i.v 12 hourly for 4 weeks. Or, Penicillin G 3-4 million units i.v 4 hourly for 4 weeks. Plus, Gentamicin 80mg i.v 12 hourly for 4 weeks. Or, Vancomycin 15mg/kg i.v 12 hourly i.v for 4 weeks (in case of penicillin-allergic patients). Plus, Gentamicin 80mg i.v 12 hourly for 4 weeks Treatment for patients at high risk for relapse should continue for 6 weeks. 4. Staphylococci- Penicillin-susceptible staphylococci, penicillin G (benzyl penicillin) 3-4 million units (or 1.2gm) i.v 4 hourly for 4 weeks. Or, In case of penicillin-resistint but methicillin-susceptible staphylococci, nafcillin or oxacillin 1.5-2gm i.v 4 hourly for 6 weeks, or flucloxacillin 2gm i.v 4 hourly for 4 weeks. Or, In case of penicillin- and methicillin-resistant staphylococci, vancomycin Igm or 15mg/kg i.v 12 hourly for 4 weeks, plus gentamicin 80mg (or Img/kg) i.v 8 hourly for 4 weeks. 5. HACEK Organisms- Ceftriaxone (or other third generation cephalosporin) 2gm once daily for 4 weeks (or 6 weeks in case of prosthetic valve endocarditis). Indications for Surgery: 1. Valve rupture. 2. intractable cardiac failure. 3. Resistant infection. 4. High relapse rate. |
| Introduction | Infective endocarditis is an infection of the endocardial lining of heart valves (native or prosthetic), chambers or vascular endothelium. The causative organisms are usually bacteria, but rarely may be rickettsia, chlamydia or fungi. The disease may occasionally occur as a fulminating or acute infection, but more commonly runs an insidious course and hence known as ‘subacute bacterial endocarditis’. The clinical course and presentation of the disease depends on the- i. type of the causative organism, ii. which valve or valves or part of the heart affected, and iii. the source or route of the infection |
| History | History: 1. History of tooth extraction 2. History of respiratory tract infection 3. History of catheterisation, cystoscopic examination, delivery etc. 4. History of known abnormality of valve or disease of valve. |
| Etiology | Etiology:12,3 Many organisms may cause infective endocarditis. The initiating event is intravascular contamination by pathogenic organisms. Contamination may occur directly or may result from transient or persistent bacteremia. Transient bacteremia is common during dental, upper respiratory, urologic, and lower gastrointestinal diagnostic and surgical procedures. Intravenous drug abuse is a major cause of endocarditis and is the commonest source of right sided (especially tricuspid) lesions. Most patients who develop infective endocarditis (rather than drug abusers) have underlying cardiac disease. Abnormal valves or endocardial changes due to jet flow effects in congenital lesions provide a nidus for infection during bacteremic episodes. Common age group- usually elderly patients. Most common organisms are: 1. Streptococcus viridans- 60% (common cause in dental & upper respiratory procedure). 2. Staphylococcus aureus- 20% (cellulitis or skin abscess are often cause). 3. Enterococcus faecalis- 5-10% (common cause in g.i & genitourinary procedures). Less common organisms are: 1. Staph. epidermidis 2. Histoplasma 3. Brucella 4. Candida 5. Aspergillus 6. Coxiella burnetti These (1-5) are particularly common in patients with intravenous drug addicts. HACEK organisms1'2 - these are also responsible for 5-10% infections. 1. Haemophilus aphrophilus 2. Haemophilus parainfluenzae 3. Actinobacillus actinomycetemcomitans 4. Cardiobacterium hominis 5. Eikenella corrodens and 6. Kingella kingae |
| Clinical Features | Clinical features:123 Presenting features of infective endocarditis usually vary on their clinical course. Subacute endocarditis: 1. Persistant or intermittent fever 2. Unusual tiredness. 3. Night sweats or weight loss. 4. Malaise, anorexia, and backache may present. 5. Signs of anemia, purpura, petechial haemorrhages in the skin and mucous membranes, splinter haemorrhages under the finger or toe nails. 6. Shifting apex beat due to enlargement of the heart may be present. 7. Signs of heart failure, conduction disorders may be present. 8. Mild splenomegaly (usually isolated, in long-standing patient). 9. Microscopic haematuria commonly present (60-70%). 10. Delayed features: a. Cerebral embolic manifestations (15%), such as haemiplegia, paraplegia etc. b. Systemic or peripheral embolic manifestations (7%). c. Clubbing; osier node; roth spot may be present. 11. In most cases subacute endocarditis present in patients with congenital or valvular heart disease. Acute endocarditis: Acute or fulminating endocarditis usually presents with- 1. Severe febrile illness 2. Prominent and changing heart murmurs 3. Petechial haemorrhage 4. Cerebral and peripheral embolic manifestations (common) 5. Cardiac failure may develop rapidly. 6. Renal failure may also develop rapidly. 7. Endocardial abscess may be detected on echocardiography. 8. Clinical stigmata of chronic or subacute endocarditis are usually not found. Post-operative endocarditis: Unexplained fever following any cardiac valve surgery mostly due to infective endocarditis, which may present as subacute or acute from. In this condition, patient should be investigated for possible cause of infective endocarditis. |
| Preventions | Prevention: 1. Ensure and maintain good dental health. 2. In case of dental & upper respiratory tract procedures-Oral, amoxycillin 3gm 1 hour before procedure & l.5gm 6 hours later. Or, In penicillin-allergy erythromycin Igm 2 hours before procedure & 0.5gm 6 hours later. Or, Clindamycin 300mg orally 1 hour before procedure & 150mg 6 hours later. Parenteral, ampicillin 2gm i.m or i.v 30 minutes before procedure, plus, Gentamicin 1.5mg/kg i.m or i.v 30 minutes before procedue. Or, In penicilin-allergy vancomycin Igm i.v infused slowly over 1 hour beginning 1 hour before procedure. Or, Clindamycin 200mg i.v 30 minutes before procedure & an i.v or oral dose of 150mg 6 hours later. 3. Operation on G I. tract or Urinary tract- Oral, amoxycillin 3gm 1 hour before procedure and l.5gm 6 hours later. Parenteral, ampicillin plus gentamicin (dosage as above). Or, in penicillin-allergy, vancomycin plus gentamicin (dosage as above) |
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