11. IE_1 final.ppt

INFECTIVE ENDOCARDITIS INTRODUCTION • Infective endocarditis (IE) is defined as an infection of the endocardial surface of the heart which may include one or more heart valves, the mural endocardium, or a septal defect. • an acute, fulminating infection, • subacute bacterial endocarditis (SBE.)...

INFECTIVE ENDOCARDITIS INTRODUCTION • Infective endocarditis (IE) is defined as an infection of the endocardial surface of the heart which may include one or more heart valves, the mural endocardium, or a septal defect. • an acute, fulminating infection, • subacute bacterial endocarditis (SBE.) INFECTIVE ENDOCARDITIS Definition: Endocarditis is usually the consequence of two factors: • the presence of organisms in the bloodstream • and abnormal cardiac endothelium facilitating their adherence and growth. Microbial infection of the endothelial surface of valves, Septal defect, chordae tendineae, mural endothelium Which valves are at risk? • NVE: native valve endocarditis • PVE: prosthetic valve endocarditis • Note: without treatment the mortality approaches 100% • with treatment also, significant morbidity and mortality. Incidence: 2 / 100,000 patient-years, • 15—30 / 100,000 patient-years ( >60 y/o Types of infective endocarditis NVE: native valve endocarditis Acute NVE frequently involves normal valves and usually has an aggressive course. Staph aureus/Gp.B streptococci Subacute NVE typically affects only abnormal valves usually more indolent Alpha-hemolytic streptococci or enterococci, Prosthetic valve IE 10-20 % of cases HT disease at risk • Rheumatic heart disease • Congenital heart disease – ASD/VSD • Mitral valve prolapse with regurgitation • Degenerative heart disease • Asymmetrical septal hypertrophy • Intravenous drug abuse • Prosthetic valve (7—25%) FACTORS CAUSING BACTERAEMIA • Weakness of the body's innate defences can potentially cause bacteraemia. Source of infection • Poor dental hygiene • Intravenous drug use • Soft tissue infections • Iatrogenic: Dental treatment, Intravascular cannulae (CVP), Cardiac surgery, Permanent pacemakers. Which microrganisms are involved? Available source of infection Mouth IVDU GI/GU Prosthetic valves Streptococci Staphylococci Enterococci Staph Infective endocarditis: microorganism • Gram negative bacteria: upper respiratory tract and oropharyngeal flora, B/C incubation 3 weeks P. aeruginosa: most common in Gram negative IE / IVDU • Fungus: drug abuser and post valve replacement common: C. albicans (PVE); C. parapsilosis (NVE) Culture Negative Endocarditis • Most common cause is recent use of antibiotics. • Fastidious organisms • Fungal • Intracellular agents: Bartonella, chlamydia, viruses. • Non-infectious The HACEK organisms are a group of fastidious gram-negative bacteria that are an unusual cause of infective endocarditis, which is an inflammation of the heart due to bacterial infection. Haemophilus, Aggregatibacter (previously Actinobacillus), Cardiobacterium, Eikenella, Kingella Pathophysiology Infective endocarditis: pathophysiology • Local destruction of intracardiac infection: valve, chordae tendineae, fistula, paravalvular abscess, conduction abnormalities • Distant embolization with infarct or infection: 45 —65% (autopsy), 70% pulmonary embolism in R’t IE • Hematogenous seeding with bacteremia: metastatic infection, • Immune-complex or antibody reaction: IgM, IgA, IgG, Osler’s node, Rheumatoid factor, Roth’s spot Clinical Features • Fever: most common • Heart murmur: 80—85% • Enlargement of spleen: 15—50% • Petechiae: most common peripheral sign • Splinter or subungual homorrhages, Osler’s nodes, Janeway’s lesions, Roth’s spots Clinical Features • Myalgia, arthralgia, back pain • Systemic emboli • Neurological: 30—40%, embolic stroke (most common), mycotic aneurysm, • Renal insufficiency: immune-complex mediated glomerulonephritis (azotemia); embolic renal infarct (hematuria) Peripheral Manifestations • Janeway Lesions: – erythematous, macular, non tender. – septic emboli? Conjunctival Petechiae Janeway lesion Splinter Haemorrhage Roth Spots Clubbing Diagnosis-Duke Criteria • “Definite”: pathologic diagnosis – Micro-organisms or – Pathologic lesion (confirmed by histology) • clinical diagnosis – 2 major criteria or – 1 major criterion plus 3 minor criteria or – 5 minor criteria Diagnosis • Frequently difficult to diagnose with certainty. – Highly variable – often non-specific presentation. • Overdiagnosis • Underdiagnosis are common. “Echo should be done in all cases of suspected endocarditis.” (This is not in all patients with fever or positive blood cultures). Lab Investigations • Anemia of Chronic Disease in 50-80% • ESR “almost always” elevated. – May be normal in those with CHF. • Urinalysis – gross or microscopic hematuria – casts in glomerulonephritis – bacteriuria and pyuria • Elevated BUN and Creatinine • Rheumatoid factor present in 50% Principles of Therapy • Therapy of endocarditis is difficult because organisms reside within a protected site within the vegetation. High concentrations of intravenous antibiotic are required for prolonged periods to achieve successful treatment Medical Management • Tailor therapy to results of susceptibility testing. • Use parenteral drugs / high doses • Plan for prolonged courses of antibiotics 4-6 weeks – Be vigilant for adverse drug effects. • Synergistic combinations are useful. • Monitor levels of aminoglycosides. Viridans group streptococci and Streptococcus bovis are usually highly susceptible to penicillin and can be treated with penicillin or ceftriaxone The most common organism responsible for infective endocarditis is Staphylococcus aureus, cloxacillin Antibiotic treatment of infective endocarditis due to oral streptococci Penicillin G12–18 million U/day i.v. either in 4–6 doses orcontinuously or Amoxicilline100–200 mg/kg/day i.v. in 4–6 doses or Ceftriaxone2 g/day i.v. or i.m. in 1 doseor Duration 4 weeks NVE caused by methicillin-sensitive S aureus (MSSA) should be treated as follows: Administer nafcillin or oxacillin at 2 g IV every 4 hours for 4-6 weeks Methicillin-susceptible staphylococci (Flu)cloxacillin or oxacillin 12 g/day i.v. in 4– 6 doses Penicillin-allergic patients or methicillinresistant staphylococci Vancomycin ** 30–60 mg/kg/day i.v. in 2–3 doses Duration 4-6weeks Complications Occur in Over Half of All Cases • Embolic: CNS and Peripheral – Ischemic infarcts 90% of these in MCA distribution – Hemorrhagic – Septic: mycotic aneurysm metastatic abscess • Local invasive Conduction abnormalites Valvular dysfunction Congestive Heart Failure • Glomerulonephritis Infective endocarditis • Extracardiac complications Splenic abscess: percutaneous needle aspiration for diagnosis drainage for successful treatment Mycotic aneurysm and septic arteritis: cerebral cortex, middle cerebral artery branches septic emboli with secondary arteritis: S. aureus bacterial seeding Streptococcus viridans Congestive Heart Failure • High associated mortality – Accounts for 80-90% of IE deaths • Leading indication for surgery • More common with AV involvement • More common with Staph aureus? • Surgery is strongly indicated in most cases. – In-house death reduced from 51% to 9%. – Once CHF develops, – surgery should be performed promptly. PROPHYLAXIS Today, antibiotics before dental proceduresre only recommended fo patients with the highest risk of IE, those who have:prosthetic heart valve or who have had a heart valve repaired with prosthetic material. A history of endocarditis. A heart transplant with abnormal heart valve function Certain congenital heart defects Additionally, taking antibiotics just to prevent endocarditis is not recommended for patients who have procedures involving the reproductive, urinary or gastrointestinal tracts. Also consider prophylaxis in patients before they undergo procedures that may cause transient bacteremia, such as the following •Any procedure involving manipulation of gingival tissue or the periapical region of teeth, or perforation of the oral mucosa •Any procedure involving incision in the respiratory mucosa •Procedures on infected skin or musculoskeletal tissue including incision and drainage of an abscess •Prophylaxis is no longer routinely recommended for gastrointestinal or genitourinary procedures. IE prophylaxis • High risk: normal population: (pre-30 min) Ampicillin 2g IV/IM + GM 1.5mg/kg (post-6 hour) Ampicillin 1g IV/IM or Amoxicillin 1g po penicillin allergy: (pre-30 min) Vancomycin 1g IVD + GM 1.5mg/kg (post-6 hour) no second dose IVDU infective endocarditis no previous history of heart disease or murmur on admission. Pulmonary manifestations may be prominent in patients with tricuspid infection CONCLUSION • IE is one of the condition which presents with common symptoms & organism, but still difficult to diagnose due to variable modes of presentations. We have to have to keep the possibility of infective carditis and try to suspect it for an early diagnosis & intervention, as an iatrogenic error on our part, may prove to be life threatening to the patient THANK YOU