Infectious endocarditis

Infectious endocarditis

Infective endocarditis (IE) is an inflammatory disease of the endocardium (valves, rarely parietal) as a result of infection with microorganisms (bacteria, fungi and rickettsia). The frequency is 0.03-0.3% of all hospitalized patients. Classification. There are acute and subacute IE. Etiology. Described within 120 causative agents of IE, more than half are gram-negative bacteria

• • Acute IE is more often caused by: Staphylococcus aureus, pyogenic streptococcus, gram-negative bacteria; isolated and L-forms of the coccal group of viruses
  • Subacute IE has traditionally been associated with Streptococcus viridans, Enterococci, and valvular infections are more commonly caused by Staphylococcus aureus.
  • With IE drug addicts – Staphylococcus aureus, Pseudomonas aeruginosa, other gram-negative rods, enterococci, fungi of the genus Candida
  • With IE of artificial valves, the most common etiological agents are Staphylococcus aureus, Staphylococcus epidermidis, a-hemolytic streptococci, gram-negative rods, fungi of the genus Candida, aspergillus.

 

Risk factors

• • Artificial heart valves
  • UPU
  • Rheumatic and other acquired valvular disorders
  • Hypertrophic cardiomyopathy
  • Mitral valve prolapse with valvular regurgitation
  • Any diagnostic and therapeutic procedures using catheters, endoscopic instruments
  • Dental procedures
  • Operations affecting the mucous membrane of the respiratory tract, gastrointestinal tract, urinary tract in the presence of infection of these organs
  • Physiological delivery in the presence of infection of the birth canal
  • Addiction.

 

Pathomorphology

• • Vegetations of the endocardium are represented by organized fibrin, settled platelets, colonies of microorganisms
  • The aortic valve is often affected, less often the mitral valve (valve destruction – perforation, rupture of the leaflets, rupture of tendon chords)
  • Mycotic aneurysms are typical as a result of direct invasion by microorganisms of the wall of the aorta, vessels of internal organs, and the nervous system.
  • Heart attacks, abscesses and microabscesses are found in the heart and in various organs.

The clinical picture is manifested by a nonspecific variable toxic-infectious syndrome.

• • Complaints
  • Body temperature – from normal to febrile values. Sometimes fever is the only symptom of IE of prosthetic heart valves
  • Chills and severe sweating
  • Muscle weakness, numbness, cold extremities, muscle pain
  • Anorexia, weight loss
  • Headache
  • Chest pain, cough.
  • Inspection
  • Integuments of the color of coffee with milk (due to anemia and intoxication).
  • Hemorrhages in the conjunctiva, hemorrhagic rash, Roth’s spots (on the retina), Osler’s nodules (on the skin), Janeway’s symptom (red spots on the soles and palms).
  • The auscultatory picture is variable and depends on concomitant cardiac pathology.
  • Systolic murmur from functional to holosystolic
  • Sound phenomena – systolic clicks
  • Cardiac arrhythmias
  • Rubbing noise of the pericardium
  • Rubbing noise of the pleura
  • Embolic lesions – kidneys (kidney infarction with the development of renal failure), adrenal glands (from transient vascular disorders to fatal acute renal failure), brain (intracranial hemorrhages with severe neurological disorders), intestines (with ulcerative enterocolitis).

 

Laboratory research

• • Blood culture for blood culture – positive repeated inoculations of the pathogen (at least 2 inoculations)
  • Increased ESR, neutrophilic leukocytosis with a shift to the left (with acute IE), leukopenia (with subacute course), anemia,

thrombocytopenia, increase in CRV and seromucoid, detection of RF

• • Immunological examination – CEC, positive test with AT against IgM and IgG
  • Micro- or macrohematuria, proteinuria, leukocyturia.

 

Special Studies

• • ECG – rhythm disturbance: tachycardia or bradycardia, extrasystole, atrioventricular conduction disturbance, signs of MI, subendocardial ischemia and cardiosclerosis are possible
  • Echocardiography – an increase in the cavities of the heart, a decrease in the ejection fraction, signs of damage to the valves or parietal endocardium, the presence of vegetation; reveals the nature of the heart disease
  • X-ray examination of the chest organs is most informative in exudative pericarditis
  • Transesophageal echocardiography for prosthetic valves
  • Cardiac catheterization with an unexplained degree of valve deformity.

 

Differential Diagnosis

• • brain abscesses
  • Embolism of cerebral vessels, pulmonary and carotid arteries
  • Diffuse connective tissue diseases
  • Immunodeficiency states
  • Glomerulonephritis
  • Meningitis
  • THEM
  • Osteomyelitis
  • Pericarditis
  • salmonellosis
  • Tuberculosis.

 

Treatment:

Lead tactics. From the moment of diagnosis – immediate hospitalization, as the condition improves, regular outpatient monitoring. Treatment of the underlying disease. Posyndromic therapy. Drug therapy

• • Drugs of choice
  • For IE caused by penicillin-susceptible virulent streptococci or Streptococcus bovis
  • Benzylpenicillin sodium salt 10–20 million U/day IV every 4–6 hours and gentamicin 1 mg/kg (up to 80 mg) IV every 8 hours for 2 weeks (6 weeks for IE of prosthetic valves)
  • Benzylpenicillin sodium salt 10-20 million IU/day IV every 4-6 hours for 4 weeks – patients over 65 years of age, with damage to the VIII cranial nerves, with impaired renal function.
  • In case of IE caused by enterococci, benzylpenicillin sodium salt 20-40 million U/day IV after 4 hours in combination with gentamicin 1 mg/kg (up to 80 mg) IV or IV after 8 hours for 4- 6 weeks (6 weeks for IE of prosthetic valves). It is recommended to determine the sensitivity of the pathogen to gentamicin and streptomycin in vitro (minimum inhibitory concentration >2,000 µg/ml). With resistance only to gentamicin, streptomycin 7.5 mg / kg (up to 500 mg) intravenously and 2 times a day is prescribed instead.
  • For IE caused by Staphylococcus aureus, oxacillin 2 g IV every 4 hours for 6 weeks. During the first 3-5 days, can be combined with gentamicin 1 mg/kg (up to 80 mg) IV or IV after 8 hours.
  • For prosthetic valve IE caused by staphylococci, vancomycin 15 mg/kg (traditionally 1 g) as an IV infusion over 1 hour after 12 hours and rifampin (rifampicin) 300 mg every 8 hours orally for 6 weeks; during the first 2 weeks, combined with gentamicin 1 mg / kg (up to 80 mg) intravenously or intramuscularly after 8 hours.
  • Precautions
  • The combination of vancomycin and gentamicin increases the likelihood of nephrotoxicity.
  • When using gentamicin for more than 5 days or in case of impaired renal function, it is recommended to periodically determine the concentration of the product in the blood (the largest is within 3 μg / ml, the average

njaya therapeutic – decrease by no more than on 1 mcg/ml is probable)

• • In case of impaired renal function, periodic determination of the concentration of vancomycin in the blood is recommended (the highest is 30–45 μg / ml, a decrease of no more than 10 μg / ml is likely)
  • When using gentamicin, it is necessary to determine the content of urea and creatinine in the blood 2 times a week
  • Due to the ototoxic effect of aminoglycosides, audiometry will be required at the beginning and during treatment.
  • Second-line drugs are prescribed for penicillin allergy.
  • For IE caused by penicillin-susceptible virulent streptococci or Streptococcus bovis, cefazolin 1 g iv 8 h later, ceftriaxone 2 g iv or iv 24 h later (not used for immediate allergic reaction to penicillin) or vancomycin 15 mg/kg (usually 1 g) as an intravenous infusion over 1 hour after 12 hours for 4 weeks (6 weeks for IE of prosthetic valves).
  • For enterococcal IE, penicillin desensitization or vancomycin 15 mg/kg (usually 1 g) as an intravenous infusion over 1 hour after 12 hours and gentamicin 1 mg/kg (up to 80 mg) after 8 hours are recommended. 4-6 weeks (6 weeks for IE of artificial valves).
  • For Staphylococcus aureus IE, cefazolin 2 g IV every 8 hours (not for immediate penicillin allergic reaction) or vancomycin 15 mg/kg (usually 1 g) as an IV infusion over 1 hour every 12 hours ; the duration of treatment is 6 weeks (including with IE of artificial valves). Surgery. Heart surgery to repair the infected valve is performed before the completion of the course of antibiotic therapy if indicated:
  • Congestive heart failure due to valvular insufficiency
  • Development of multiple extensive systemic embolisms
  • In IE caused by antibiotic-resistant microorganisms (fungi, Pseudomonas aeruginosa)
  • Fractured infected prosthetic valve
  • Recurrent IE of the prosthetic valve
  • Persistent bacteremia despite ongoing antibiotic therapy.

 

Complications

• • Heart failure
  • Rupture of the leaflets of the heart valve
  • Embolism of cerebral vessels, lungs, carotid arteries
  • Aneurysm of the sinus of Valsalva
  • aortic abscesses
  • Abscess of the myocardium, brain
  • THEM
  • Pericarditis
  • Rhythm disturbance
  • Meningitis
  • Ruptured mycotic aneurysm
  • Septic infarcts and lung abscesses
  • Spleen infarcts
  • Glomerulonephritis
  •  OPN.

The course and prognosis depend on the type of IE pathogen, comorbidities, and severity of complications.

• • In staphylococcal IE, fever and positive blood cultures persist for 10 days after initiation of treatment
  • In streptococcal IE, the response to antibiotic therapy occurs within 48 hours, after the start of treatment, the results of blood cultures should be negative
  • In the absence of treatment – a lethal outcome.

Prophylaxis is indicated for all patients at risk (see Risk Factors). After the treatment of IE – regular sanitation of the teeth, if necessary – drug prophylaxis.

• • Prophylactic antibiotic therapy for dental and surgical interventions that cause transient bacteremia (including patients with artificial valves).
  • Interventions in the oral cavity or in the upper respiratory tract
  • Amoxicillin 3 g orally 1 hour before the procedure, then 1.5 g 6 hours after the first dose
  • If allergic to penicillin – erythromycin 1 g orally 2 hours before the procedure, then 500 mg 6 hours after the first dose; or clindamycin 300 mg orally 1 hour before the procedure and 150 mg 6 hours after the first dose.
  • Alternative antibiotic regimens for interventions in the oral cavity or in the upper respiratory tract
  • If oral intake of products is unlikely – ampicillin 2 g IV (or IV) 30 minutes before the procedure, then after 6 hours 1 g IV (or IV)
  • For penicillin allergy, clindamycin 300 mg IV 30 minutes before the procedure and 150 mg IV (or orally) 6 hours later.
  • With interventions in the gastrointestinal tract or genitourinary system
  • Ampicillin 2 g IV (or IV) and gentamicin 1.5 mg/kg IV (or IV) (no more than 80 mg) 30 minutes before the procedure, then amoxicillin 1.5 g orally through 6 hours (or repeated parenteral administration of products after 8 hours)
  • For penicillin allergy, vancomycin 1 g IV as an infusion over 1 hour and gentamicin 1.5 mg/kg IV (or IV) (no more than 80 mg) 1 hour before the procedure and as needed will be again in 8 hours.
  • Alternative antibiotic regimen for low-risk patients with interventions in the gastrointestinal tract or genitourinary system: amoxicillin 3 g orally 1 hour before the procedure, then 1.5 g after 6 hours.

 

Synonym. Bacterial endocarditis

See also Cardiac arrhythmias, Aneurysm, Heart failure, Mitral valve prolapse Contraction. IE – infective endocarditis

• 138 Endocarditis, valve not specified
• 139
• Endocarditis and valvular heart disease in diseases classified elsewhere