Lecture endocarditis infection

2021-08-05 06:30 PM

When bacteremia is present, the bacteria attach to the damaged endothelium and reproduce and form the warts of infective endocarditis (including platelets, fibrin, and bacteria)

Outline

Infective endocarditis is a common disease caused by the spread of pathogenic bacteria from localized infectious foci of the endocardium and endocardium of the arteries. Usually occurs in patients with pre-existing heart disease (low posterior valvular heart or congenital heart), a large transvalvular pressure gradient.

Prognosis is often severe and mortality is high.

Classify: 

Infective endocarditis on natural valves:

Infectious endocarditis in intravenous drug addicts depends on which heart is damaged: tricuspid valve damage is common, easily causing pulmonary embolism => pulmonary infarction. The prognosis is good because antibiotic treatment usually resolves.

Infective endocarditis on prosthetic valve:

Less than or equal to 2 months after valve replacement is usually due to intraoperative prosthetic valve infection or postoperative complications. Common bacteria are coagulase-negative staphylococcus, S. aureus, gram-negative bacilli, diphtheroid, and fungi

2-12 months is also a nosocomial infection but with a slow onset

Greater than 12 months usually resembles community-acquired infection on spontaneous valves.

Infectious endocarditis in some special subjects: Infectious endocarditis after open-heart surgery, Infective endocarditis in obstetrics and gynecological patients, Infectious endocarditis in hospital, Infectious endocarditis in patients on routine hemodialysis

Bacteria:

Streptococcus viridans, staphylococci, HACEK (Hemophyllus, Actinobacillus, Cardiobacterium, Eikenella, Kingella): origin oropharyngeal, upper respiratory skin.

Streptococcus Bovis; gastrointestinal tract or in association with polyps or colon tumors.

Enterococci from the urogenital tract.

S. aureus => Acute infective endocarditis.

Other bacteria: Pneumococcus, Streptococcus group A, and gonococcus.

Rare: enterococci, gram-negative bacilli.

Rickettsia mold.

Way in:

From the lesion, bacteria cause sepsis, bacteremia.

Maxillofacial: teeth and gums, Amygdales.

Gives.

Urogenital.

Digestion.

Tips.

Drugs: intravenous route => local congestion, sepsis, bacteremia => localized in the heart valve.

Pre-existing heart disease.

Factors related to resistance and immunity

Pathogenesis

Subacute infective endocarditis

Lesions Subacute infective endocarditis almost always occurs in already damaged endothelium. Endothelial damage is caused by three mechanisms:

The high-velocity blood flow hits the endothelium.

Blood flow from the high-pressure chamber into the low-pressure chamber.

High-velocity blood flow through a narrow opening.

When bacteremia is present, the bacteria attach to the damaged endothelium and reproduce and form the warts of infective endocarditis (including platelets, fibrin, and bacteria).

Acute infective endocarditis

Germs can attach to a healthy endocardium and cause direct infection on healthy endocardium (50% of cases without underlying heart disease).

Clinical and subclinical

Clinical

The classification of acute and subacute formerly based on disease description and time from onset to death is now based on the characteristics and progression of the disease from onset to diagnosis.

Sub-level (Osler)

Grant

- Occurs in pre-existing heart disease

- Less virulent bacteria

- Symptoms gradually

+ Mild fever £39.4 0 C

Damage to the structure of the bradycardia valve

Rarely causes infections in remote locations.

+ Disease progresses gradually unless large embolism or rupture of aneurysm develops: weeks ®months, death if not treated

Occurs in normal heart disease (50%)

- Common highly virulent Staphylococcus aureus bacteria

- Acute and severe illness

+ High fever (39.4-40 0 C)

+ Rapid destruction of the structure of the heart

Blood-borne infections in sites other than the heart.

- no treatment will lead to death within weeks

Clinical features of nonspecific infective endocarditis. However, these symptoms in a febrile patient with a valvular disease or intravenous drug use suggest the diagnosis of infective endocarditis, or when bacterial sepsis commonly causes endocarditis. pericardial infection, or unexplained arterial embolism, and progressive regurgitation.

Characteristics

Frequency %

Neurological manifestations

Frequency%

clinical

 

Peripheral manifestations (osler nodules, subungual hemorrhages, Janeway, Roth's pot

20 - 40

Fever

80 - 90

Bleeding spot

2 - 15 

Chills, sweating

40 - 75

Subclinical

10 - 40

Anorexia, weight loss, irritability

25 - 50

Anemia

 

Muscle and joint pain

15 - 30

White blood cells increase

70 - 90

Backache

7 - 15

Microscopic hematuria

20 - 30

Heart murmur

80 - 85

Elevated erythrocyte sedimentation rate

30 - 50

New or changed valvular murmur 

10 - 40

Low factor

> 90

Arterial embolism

20 - 50

Circulating immune complex

50

Spleen

15 - 50

Decreased serum complement

65 - 100

Drumstick Fingers

10 - 20

 

5 - 40

In elderly, debilitated or heart failure patients, severe renal failure may be febrile or non-febrile.

Subclinical

Blood culture, antibiotic chart:

Blood culture (+) in infective endocarditis is about 85-95%.

Infective endocarditis Subacute: 3 blood samples within 24 hours, If blood cultures are still negative after 48-72 hours, 2-3 more samples should be cultured. If the patient has been on antibiotics before, blood cultures should be done 24 - 48 hours after stopping the antibiotics for as long as a week (4 - 6 weeks for hard-to-grow bacteria, a variety of media). Empiric antibiotics should not be given if the patient's hemodynamic status is stable.

Acute infective endocarditis: 3 cultures, 3 different sites, 15 - 30 minutes apart before starting empiric therapy.

Echocardiography:

Echocardiography contributes a lot of information for the diagnosis of infective endocarditis: warts, annulus abscess.

When detecting nodules => high risk of embolism, heart failure, valve destruction.

Normal ultrasonography does not rule out infective endocarditis.

Need differential diagnosis: Mucinous degeneration, ligament rupture, atrial mucinous tumor, thrombus

Note: The papule may persist for 3 years after the clinical cure.

Diagnose

DUKE University diagnostic criteria for infective endocarditis.

Main standard

Positive blood cultures:

Isolation of typical bacteria from 2 separate blood samples (Streptococci viridans, Streptococcus bovis, S. aureus, enterococcus, HACEK group) without a primary source of infection) or isolates consistent with endocarditis conjunctivitis in (1) at least two blood samples > 12 hours apart, or (2) all 3 or more of 3 samples with the first and last samples at least 1 hour apart.

Evidence of endocardial damage:

Typical echocardiography.

Movable warts (mobility within the heart, on valves or supporting structures, or in the path of retrograde blood or on graft), or

Abscess or

Shot of a newly emerging part of the prosthetic valve, or

New valve opening.

Sub-Criteria

Have lesions that are prone to infective endocarditis or drug addicts.

Fever > 38 0 C.

Vascular phenomena: arterial embolism, pulmonary infarction due to warts, aneurysms, intracranial hemorrhage, ocular mucosal hemorrhage, Janeway lesions.

Immune phenomena: glomerulonephritis, Osler's nodule, Roth's spot, low factor.

Blood cultures were positive but did not meet the primary criteria.

Ultrasound was consistent with infective endocarditis but did not meet the primary criteria.

Definitive diagnosis: When present

2 major criteria or one major standard with 3 minor criteria or

5 sub-criteria.

Possible infective endocarditis:

Did not meet the defined criteria, but also did not belong to the exclusion group.

Diagnosis of exclusion:

There is another definite diagnosis or complete disappearance of symptoms after 4 days of antibiotics or no pathological evidence of infective endocarditis at the surgery or at autopsy with only <4 days of antibiotic therapy.

Treatment

Internally medical treatment

Time to start antibiotic therapy:

Depending on the course of the disease, the patient's clinical condition

General principles of antibiotic therapy:

Use high-dose, bactericidal antibiotics.

Intravenous or intramuscular.

Prolonged to kill all germs (4 - 6 weeks) based on antibiogram.

Combination of antibiotics: increase effectiveness and avoid selectively resistant strains of bacteria.

Empiric antibiotic therapy:

Based on the presence or absence of prosthetic heart valves and disease progression

Patients without prosthetic heart valves and subacute infective endocarditis:

 Usually caused by Streptococcus viridans, Streptococcus Bovis, Enterococcus in which Enterococcus is the most resistant bacteria: Ampicillin (or Amoxicillin) 200mg/kg/day divided into 6 intravenous injections or penicillin G 400,000 units/kg/day divided into 6 intravenous injections Intravenous combination with gentamycin 1mg/kg every 8 hours, if the patient is allergic to penicillin, then vancomycin 30mg/kg/day divided into 3 slow intravenous infusions.

Patients without prosthetic heart valves and acute infective endocarditis:

Antibiotics should be given before blood culture results are usually obtained for staphylococcus. Oxacillin 150-200mg/kg/day divided into 6 intravenous injections plus Gentamycin 1mg/kg IV every 8 hours. If the patient has hospital-acquired infectious endocarditis or if allergic to penicillin, replace oxacillin with vancomycin 30mg/kg/day divided into 2 to 3 slow intravenous infusions.

Infective endocarditis in patients with prosthetic valves:

Within 12 months of valve replacement surgery: usually caused by staphylococcus (epidermidis; aureus), gram-negative Bacilli, diphtheroid, or fungi.

12 months after valve replacement: usually caused by staphylococcus (epidermidis; aureus), or HACEK group of empiric antibiotics including vancomycin (30mg/kg/day divided 2-3 times) in combination with an aminoglycoside and including a 3rd generation cephalosporin against gram-negative bacilli.

Antibiotic treatment according to pathogenic bacteria:

Regimen 1. Antibiotics for infective endocarditis caused by penicillin G sensitive streptococcus.

 

Antibiotic

Dosage and route of administration

Time (week)

A

Penicillin G

12-18 million units (200,000-300,000 units/kg)/day IV divided every 4 hours

4

B

Penicillin G

+ Gentamycin

dose as above

1mg/kg every 8 hours intravenously or intramuscularly

4

2

C

Penicillin G

+ Gentamycin

dose as above

dose as above

2

2

D

Ceftriaxone

2g/day intravenously or intramuscularly only once a day

4

E

Vancomycin

15mg/kg IV every 12 hours

4

Regimen 2. Antibiotics for streptococcus infective endocarditis with ARB > 0.1 mcg/ml and < 0.5 mcg/ml.

Antibiotic

Dosage and route of administration

Time (week)

Penicillin G


Gentamycin

12-18 million units (200,000-300,000 units/kg)/day IV divided every 4 hours

1mg/kg every 8 hours intravenously or intramuscularly

4


2

Regimen 3. Antibiotic therapy Enterococcus infective endocarditis

 

Antibiotic

Dosage and route of administration

Time (week)

A

Penicillin G


Gentamycin

18-30 million units (400,000 units/kg)/day IV divided every 4 hours

1mg/kg every 8 hours intravenously or intramuscularly

4-6


4-6

B

Ampicillin


Gentamycin

12g (150-200mg/kg)/day, IV divided every 4 hours

dose as above

4-6

4-6

C

Vancomycin

Gentamycin

15mg/kg IV every 12 hours

dose as above

4-6

4-6

Regimen 4. Antibiotic therapy Infective endocarditis caused by Staphylococcus (natural valve)

 

Antibiotic

Dosage and route of administration

Time (week)

A

Oxacillin


Gentamycin

12g (150-200mg/kg)/day, IV divided every 4 hours

1mg/kg every 8 hours intravenously or intramuscularly

6


3-5 days

B

Cefazolin

Gentamycin

2g IV every 8 hours

dose as above

6

3-5 days

C

Vancomycin

15mg/kg IV every 12 hours

6

Regimen 5. Antibiotics for infective endocarditis caused by Oxacillin-sensitive Staphylococcus (artificial valve)

Antibiotic

Dosage and route of administration

Time (week)

Oxacillin

+ Gentamycin

+ Rifampicin

12g (150-200mg/kg)/day, IV divided every 4 hours

1mg/kg every 8 hours intravenously or intramuscularly

300mg orally every 8 hours

6


2

6

Regimen 6. Antibiotics for infective endocarditis caused by Oxacillin-resistant Staphylococcus (artificial valve)

Antibiotic

Dosage and route of administration

Time (week)

Vancomycin

Gentamycin

Rifampicin

15mg/kg IV every 12 hours

1mg/kg every 8 hours intravenously or intramuscularly

300mg orally every 8 hours

6

2

6

* Give Rifampicin when the full dose of vancomycin and gentamycin has been used

* If the Staphylococcus strain is resistant to all aminoglycosides, the aminoglycoside can be replaced with a fluoroquinolone

 

Regimen 7. Antibiotic therapy Infective endocarditis caused by bacteria of the HACEK group

 

Antibiotic

Dosage and route of administration

Time (week)

A

Ceftriaxone

2g/day intravenously or intramuscularly only once a day

4

B

Ampicillin


Gentamycin

12g (150-200mg/kg)/day, IV divided every 4 hours

1mg/kg every 8 hours intravenously or intramuscularly

4


4

Rare microorganisms:

Gram-negative bacilli of the family Enterobacteriaceae: combine 1 3rd generation cephalosporin or imipenem with 1 aminoglycoside, for 4-6 weeks.

Pseudomonas aeruginosa: a combination of ceftazidime or imipenem with 1 aminoglycoside, duration of 6 weeks, often combined with cardiac surgery because this bacterium responds poorly to antibiotics and causes extensive valve damage.

Fungal: cardiac surgery to remove warts and replace valves in combination with amphotericin B intravenous infusion (starting at 0.5mg/kg/day, gradually increasing to 1mg/kg/day) for 6-8 weeks

Negative blood cultures:

The disease has a subacute course: high-dose ampicillin + gentamycin.

The disease has an acute progression or prosthetic valve in combination with vancomycin.

If the patient is cured after 1 week, then continue antibiotics for 4 weeks. If the response is poor to antibiotics, surgery must be considered.

Monitor antibiotic therapy:

Appropriate antibiotic therapy usually improves clinical outcomes within 3 to 10 days as the patient feels better and fever subsides. Blood cultures should be cultured daily until sterilization is achieved.

If the patient still has a fever despite taking antibiotics, a blood culture must be repeated.

Prolonged or recurrent fever despite the correct antibiotic regimen according to the causative organism may be caused by:

Failure of antibiotic therapy.

Abscess complications.

Thromboembolism, thrombophlebitis.

Patients with drug hypersensitivity.

Combined disease.

Drugs should be changed only when there is clear evidence that the organism is resistant to the drug or the patient is susceptible to the drug.

Renal function should be regularly monitored in patients on prolonged aminoglycoside therapy, especially if vancomycin is used.

Echocardiography is an indispensable component in the monitoring tools for the treatment of infective endocarditis.

Indications for surgery:

Absolute indications:

Moderate to severe heart failure due to valvular dysfunction (acute valve regurgitation due to perforation or laceration, mitral occlusion by large warts).

The artificial heart valve is unstable.

Infections are not controlled with antibiotics.

Infectious endocarditis on prosthetic valve recurs after optimal antibiotic therapy.

Relative indications:

Invasive perivalvular infection.

Infectious endocarditis recurs after optimal antibiotic therapy (on natural valves).

Infectious endocarditis with blood cultures (-) and persistent fever.

Large papules > 10mm.

Time of surgery:

Ideally, antibiotics should be given 10 days before surgery, although surgery should not be delayed in critically ill patients (antibiotics should be given optimally 24 to 72 hours before surgery).

Antifreeze

If the patient has a mechanical prosthetic heart valve, take a vitamin K antagonist to keep the INR at 2.5 - 3.5.

If the patient has a bioprosthetic valve or no prosthetic heart valve, anticoagulation should not be given unless clearly indicated.

Patients with cerebral vascular occlusion due to warts or cerebral hemorrhage must discontinue anticoagulation therapy.

In patients on anticoagulation, antibiotics should not be administered intramuscularly, but intravenously.

Prognosis

The cure rate of Streptococci infective endocarditis is up to 90%.

Mortality from S. aureus in non-drug addicts is at least 40%. Death is often due to heart failure or severe infection

Infectious endocarditis in patients with prosthetic valves with early-onset (< 60 days after valve transplantation) has a worse prognosis than patients with late-onset infective endocarditis. Mortality ranges from 30 - 80% compared to 20 - 40%.

The presence of large nodules worsens the prognosis.

The poor prognostic factors are:

The causative agent is not Streptococci.

Heart failure occurs.

Injury to the aortic valve.

Prosthetic valve infection.

Old age.

There is a myocardial abscess or annulus abscess.

Preventive treatment

Prophylaxis is required in patients at risk for infective endocarditis

High risk:

Medium risk

- Prosthetic valve
- Congenital cyanotic
heart
- History of infective endocarditis - Has undergone surgery to create a shunt between the systemic and pulmonary vessels
- The ductus arteriosus
- Coarctation of the aorta

- Acquired heart valves: (eg, low posteriority)
- Mitral valve prolapse with regurgitation or thickened
valves - Aortic and bivalve stenosis
- Congenital heart without cyanosis
- Hypertrophic cardiomyopathy

Types of interventions to prevent infective endocarditis in a patient at risk.

Oral (any intervention).

Ta - nose - throat surgery; tonsillectomy, VA, surgery with airway mucosal impingement, bronchoscopy with rigid bronchoscope.

Gastrointestinal: Sclerotherapy for esophageal varices, esophageal stricture, endoscopic retrograde contrast cholangiography in the presence of biliary obstruction, biliary surgery, surgery with intestinal mucosal involvement.

Urology: prostate surgery, cystoscopy, urethral dilation.

Prophylaxis of infective endocarditis (The Washington Manual of Medical Therapeutics 1998):

Prescriptions for oral, respiratory, and esophageal procedures

Situation - Drugs and Dosage

General regimen: Amoxicillin 2g (50mg/kg) orally 1 hour before the procedure

Patients unable to take oral: Ampicillin 2g (50mg/kg) intramuscularly or intravenously within 30 minutes before the procedure 

Penicillin allergy: Clindamycin 600mg (20mg/kg) orally 1 hour before the procedure, or

Cephalexin/cefadroxil*, 2g (50mg/kg) orally 1 hour before procedure, or

Clarithromycin or Azithromycin, 500mg (15mg/kg) orally 1 hour before the procedure

Penicillin allergy: Clindamycin 600mg (20mg/kg) intravenously within 30 minutes before the procedure and cannot take orally or Cefazolin*, 1g (25mg/kg) IV within 30 minutes before the procedure

Cephalosporins should not be used in patients with anaphylaxis or urticaria reactions to penicillins:

Prescriptions for gastrointestinal and urological procedures

Situation - Drugs and Dosage

High-risk patients: Ampicillin, 2g IM or IV + gentamycin1.5mg/kg (maximum 120mg) within 30 minutes before the procedure; 6 hours later: Ampicillin 1g IM/IV or Amoxicillin 1g orally

High-risk patients: Vancomycin, 1g IV + gentamycin 1.5 mg (maximum 120mg)

Penicillin allergy ends within 30 minutes before the procedure

Low-risk patients: Amoxicillin 2g orally 1 hour before the procedure or

Ampicillin IM or IV within 30 minutes before the procedure

Low-risk patients: Vancomycin 1g IV finished within 30 minutes before the procedure

Penicillin allergy