Pediatric Bacterial Endocarditis Workup: Approach Considerations, Blood Culture, Complete Blood Coun
Pediatric Bacterial Endocarditis Workup: Approach Considerations, Blood Culture, Complete Blood Count
Under the modified Duke criteria, the clinical criteria for definite infectious endocarditis includes 2 major, 1 major and 3 minor, or 5 minor criteria, as follows (see Diagnostic Considerations.):
Major criteria include positive blood cultures, in this case 2 separate cultures for a typical endocarditis microorganism, such as Streptococcus viridans or a HACEK organism (Haemophilus parainfluenzae, H aphrophilus, H paraphrophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, or Kingella species); persistently positive blood cultures; or evidence of infection with a Coxiella organism and/or Q fever.
Another criterion is the presence of positive echocardiographic findings (eg, oscillating mass and/or vegetation, paravalvular abscess, or dehiscence of a prosthetic valve).
A third criterion is new valvular regurgitation.
Minor criteria include the following:
Go to Infective Endocarditis for more complete information on this topic.
The most definitive laboratory tests for bacterial endocarditis are multiple blood cultures that grow an organism known to cause endocarditis.
Blood cultures should be obtained from all patients with fever of unclear etiology who have a pathologic heart murmur, a history of heart disease, or previous endocarditis.
For microbiologic documentation, obtaining 5-7 mL of blood from children (1-3 mL in infants) in 3 separate samplings within 1-24 hours is recommended, according to the clinical presentation.
Venous blood samples should be obtained from different peripheral sites.
The microbiology laboratory should be notified of the clinical suspicion for endocarditis. Cultures should be grown aerobically and anaerobically for at least 1 week.
If no growth is observed by the second day of incubation, 2 more blood cultures should be obtained.
Blood cultures should be repeated during therapy to demonstrate the clearance of bacteremia.
Anemia is present in 70-90% of patients and is usually normocytic and normochromic. Leukocytosis is noted in less than 50% of patients.
The erythrocyte sedimentation rate (ESR) is elevated in almost all patients except those with CHF, renal failure, and disseminated intravascular coagulation (DIC). The mean ESR is 55 mm/h.
The C-reactive protein, although nonspecific, is elevated in most patients but decreases with successful treatment. Levels of C-reactive protein may be used to monitor response to antibiotic therapy.
A positive rheumatoid factor is observed in 40-50% of patients with endocarditis of more than 6 weeks' duration. Immune complexes are also observed in patients with prolonged disease.
Urinalysis may reveal proteinuria (50-60%) and/or microscopic hematuria (30-50%).
Echocardiography is the primary modality for detecting endocarditis in patients in whom the diagnosis is suspected. In fact, echocardiographic features suggestive of infectious endocarditis are considered major criteria for confirming the diagnosis. Typical findings include vegetations, abscesses, and new valvular insufficiency.
Transthoracic echocardiography (TTE) has a greater sensitivity in infants and children than in adults. Reported sensitivity is as high as 81%. It is the most common form of imaging used in children and is usually sufficient in most clinical circumstances.
Transesophageal echocardiography (TEE) is occasionally required when transthoracic acoustic windows are inadequate. This is most likely to occur in patients who are obese or very muscular, who have had cardiac surgery, or have pulmonary hyperinflation. TEE is especially useful in detecting aortic root abscess, involvement of the sinuses of Valsalva, and prosthetic valve dehiscence.
Magnetic resonance imaging (MRI) has identified paravalvular extension of infection, aortic root aneurysms, and fistulas. Its utility relative to echocardiography has not been widely established.
Treatment & Management
Michael H Gewitz, MD Physician-in-Chief, Chief, Section of Pediatric Cardiology, Maria Fareri Children’s Hospital at Westchester Medical Center; Professor and Vice Chairman, Department of Pediatrics, New York Medical College
Michael H Gewitz, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American Association for Physician Leadership, American Heart Association, American Pediatric Society, American Society of Echocardiography, New York Academy of Medicine, New York Academy of Sciences, Royal Society of Medicine, Society of Pediatric Echocardiography
Coauthor(s)
Brian Keith Eble, MD Associate Professor of Pediatrics, Section of Cardiology, University of Arkansas for Medical Sciences, Arkansas Children's Hospital
Brian Keith Eble, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American Heart Association, Arkansas Medical Society, Society for Cardiovascular Angiography and Interventions
Specialty Editor Board
Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Julian M Stewart, MD, PhD Associate Chairman of Pediatrics, Director, Center for Hypotension, Westchester Medical Center; Professor of Pediatrics and Physiology, New York Medical College
Julian M Stewart, MD, PhD is a member of the following medical societies: American Academy of Pediatrics, American Autonomic Society, American Physiological Society
Disclosure: Received grant/research funds from Lundbeck Pharmaceuticals for none.
Chief Editor
Steven R Neish, MD, SM Director of Pediatric Cardiology Fellowship Program, Associate Professor, Department of Pediatrics, Baylor College of Medicine
Steven R Neish, MD, SM is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American Heart Association
Jeffrey Allen Towbin, MD, MSc FAAP, FACC, FAHA, Professor, Departments of Pediatrics (Cardiology), Cardiovascular Sciences, and Molecular and Human Genetics, Baylor College of Medicine; Chief of Pediatric Cardiology, Foundation Chair in Pediatric Cardiac Research, Texas Children's Hospital
Jeffrey Allen Towbin, MD, MSc is a member of the following medical societies: American Academy of Pediatrics, American Association for the Advancement of Science, American College of Cardiology, American College of Sports Medicine, American Heart Association, American Medical Association, American Society of Human Genetics, New York Academy of Sciences, Society for Pediatric Research, Texas Medical Association, Texas Pediatric Society, Cardiac Electrophysiology Society
Acknowledgements
The authors and editors of eMedicine gratefully acknowledge the contributions of previous authors Gerardo Reyes, MD, and Dwight Bailey, MD, to the development and writing of the source article.
References
A young adult with a history of intravenous drug use diagnosed with right-sided staphylococcal endocarditis and multiple embolic pyogenic abscesses on chest radiograph.
Approach Considerations
Under the modified Duke criteria, the clinical criteria for definite infectious endocarditis includes 2 major, 1 major and 3 minor, or 5 minor criteria, as follows (see Diagnostic Considerations.):
Major criteria
Major criteria include positive blood cultures, in this case 2 separate cultures for a typical endocarditis microorganism, such as Streptococcus viridans or a HACEK organism (Haemophilus parainfluenzae, H aphrophilus, H paraphrophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, or Kingella species); persistently positive blood cultures; or evidence of infection with a Coxiella organism and/or Q fever.
Another criterion is the presence of positive echocardiographic findings (eg, oscillating mass and/or vegetation, paravalvular abscess, or dehiscence of a prosthetic valve).
A third criterion is new valvular regurgitation.
Minor criteria
Minor criteria include the following:
- Predisposition (history of IV drug use or congenital heart disease)
- Fever with a temperature of more than 38°C
- Vascular phenomena (arterial emboli, septic pulmonary infarcts, intracranial hemorrhage, conjunctival hemorrhage, Janeway lesions [painless, hemorrhagic lesions on the palms and soles])
- Immunologic phenomena (glomerulonephritis, Osler nodes, Roth spots, a positive result for rheumatoid factor)
- Positive blood culture findings without meeting the criteria above or serologic evidence of active infection consistent with endocarditis
Go to Infective Endocarditis for more complete information on this topic.
Blood Culture
The most definitive laboratory tests for bacterial endocarditis are multiple blood cultures that grow an organism known to cause endocarditis.
Blood cultures should be obtained from all patients with fever of unclear etiology who have a pathologic heart murmur, a history of heart disease, or previous endocarditis.
For microbiologic documentation, obtaining 5-7 mL of blood from children (1-3 mL in infants) in 3 separate samplings within 1-24 hours is recommended, according to the clinical presentation.
Venous blood samples should be obtained from different peripheral sites.
The microbiology laboratory should be notified of the clinical suspicion for endocarditis. Cultures should be grown aerobically and anaerobically for at least 1 week.
If no growth is observed by the second day of incubation, 2 more blood cultures should be obtained.
Blood cultures should be repeated during therapy to demonstrate the clearance of bacteremia.
Complete Blood Count
Anemia is present in 70-90% of patients and is usually normocytic and normochromic. Leukocytosis is noted in less than 50% of patients.
Erythrocyte Sedimentation Rate and C-Reactive Protein
The erythrocyte sedimentation rate (ESR) is elevated in almost all patients except those with CHF, renal failure, and disseminated intravascular coagulation (DIC). The mean ESR is 55 mm/h.
The C-reactive protein, although nonspecific, is elevated in most patients but decreases with successful treatment. Levels of C-reactive protein may be used to monitor response to antibiotic therapy.
Rheumatoid Factor
A positive rheumatoid factor is observed in 40-50% of patients with endocarditis of more than 6 weeks' duration. Immune complexes are also observed in patients with prolonged disease.
Urinalysis
Urinalysis may reveal proteinuria (50-60%) and/or microscopic hematuria (30-50%).
Echocardiography
Echocardiography is the primary modality for detecting endocarditis in patients in whom the diagnosis is suspected. In fact, echocardiographic features suggestive of infectious endocarditis are considered major criteria for confirming the diagnosis. Typical findings include vegetations, abscesses, and new valvular insufficiency.
Transthoracic echocardiography (TTE) has a greater sensitivity in infants and children than in adults. Reported sensitivity is as high as 81%. It is the most common form of imaging used in children and is usually sufficient in most clinical circumstances.
Transesophageal echocardiography (TEE) is occasionally required when transthoracic acoustic windows are inadequate. This is most likely to occur in patients who are obese or very muscular, who have had cardiac surgery, or have pulmonary hyperinflation. TEE is especially useful in detecting aortic root abscess, involvement of the sinuses of Valsalva, and prosthetic valve dehiscence.
MRI
Magnetic resonance imaging (MRI) has identified paravalvular extension of infection, aortic root aneurysms, and fistulas. Its utility relative to echocardiography has not been widely established.
Treatment & Management
Michael H Gewitz, MD Physician-in-Chief, Chief, Section of Pediatric Cardiology, Maria Fareri Children’s Hospital at Westchester Medical Center; Professor and Vice Chairman, Department of Pediatrics, New York Medical College
Michael H Gewitz, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American Association for Physician Leadership, American Heart Association, American Pediatric Society, American Society of Echocardiography, New York Academy of Medicine, New York Academy of Sciences, Royal Society of Medicine, Society of Pediatric Echocardiography
Coauthor(s)
Brian Keith Eble, MD Associate Professor of Pediatrics, Section of Cardiology, University of Arkansas for Medical Sciences, Arkansas Children's Hospital
Brian Keith Eble, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American Heart Association, Arkansas Medical Society, Society for Cardiovascular Angiography and Interventions
Specialty Editor Board
Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Julian M Stewart, MD, PhD Associate Chairman of Pediatrics, Director, Center for Hypotension, Westchester Medical Center; Professor of Pediatrics and Physiology, New York Medical College
Julian M Stewart, MD, PhD is a member of the following medical societies: American Academy of Pediatrics, American Autonomic Society, American Physiological Society
Disclosure: Received grant/research funds from Lundbeck Pharmaceuticals for none.
Chief Editor
Steven R Neish, MD, SM Director of Pediatric Cardiology Fellowship Program, Associate Professor, Department of Pediatrics, Baylor College of Medicine
Steven R Neish, MD, SM is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American Heart Association
Jeffrey Allen Towbin, MD, MSc FAAP, FACC, FAHA, Professor, Departments of Pediatrics (Cardiology), Cardiovascular Sciences, and Molecular and Human Genetics, Baylor College of Medicine; Chief of Pediatric Cardiology, Foundation Chair in Pediatric Cardiac Research, Texas Children's Hospital
Jeffrey Allen Towbin, MD, MSc is a member of the following medical societies: American Academy of Pediatrics, American Association for the Advancement of Science, American College of Cardiology, American College of Sports Medicine, American Heart Association, American Medical Association, American Society of Human Genetics, New York Academy of Sciences, Society for Pediatric Research, Texas Medical Association, Texas Pediatric Society, Cardiac Electrophysiology Society
Acknowledgements
The authors and editors of eMedicine gratefully acknowledge the contributions of previous authors Gerardo Reyes, MD, and Dwight Bailey, MD, to the development and writing of the source article.
References
- Baddour LM, Wilson WR, Bayer AS, Fowler VG Jr, Bolger AF, Levison ME, et al. Infective endocarditis: diagnosis, antimicrobial therapy, and management of complications: a statement for healthcare professionals from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, and the Councils on Clinical Cardiology, Stroke, and Cardiovascular Surgery and Anesthesia, American Heart Association: endorsed by the Infectious Diseases Society of America. Circulation. 2005 Jun 14. 111(23):e394-434. [Medline].
- Pasquali SK, He X, Mohamad Z, McCrindle BW, Newburger JW, Li JS, et al. Trends in endocarditis hospitalizations at US children's hospitals: impact of the 2007 American Heart Association Antibiotic Prophylaxis Guidelines. Am Heart J. 2012 May. 163(5):894-9. [Medline]. [Full Text].
- Johnson JA, Boyce TG, Cetta F, Steckelberg JM, Johnson JN. Infective endocarditis in the pediatric patient: a 60-year single-institution review. Mayo Clin Proc. 2012 Jul. 87(7):629-35. [Medline]. [Full Text].
- Russell HM, Johnson SL, Wurlitzer KC, Backer CL. Outcomes of surgical therapy for infective endocarditis in a pediatric population: a 21-year review. Ann Thorac Surg. 2013 Jul. 96(1):171-4: discussion 174-5. [Medline].
- Wilson W, Taubert KA, Gewitz M, Lockhart PB, Baddour LM, Levison M, et al. Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation. 2007 Oct 9. 116(15):1736-54. [Medline].
- Li JS, Sexton DJ, Mick N, Nettles R, Fowler VG Jr, Ryan T, et al. Proposed modifications to the Duke criteria for the diagnosis of infective endocarditis. Clin Infect Dis. 2000 Apr. 30(4):633-8. [Medline].
- Habib G. Management of infective endocarditis. Heart. 2006 Jan. 92(1):124-30. [Medline]. [Full Text].
- Gerber MA, Baltimore RS, Eaton CB, Gewitz M, Rowley AH, Shulman ST, et al. Prevention of rheumatic fever and diagnosis and treatment of acute Streptococcal pharyngitis: a scientific statement from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee of the Council on Cardiovascular Disease in the Young, the Interdisciplinary Council on Functional Genomics and Translational Biology, and the Interdisciplinary Council on Quality of Care and Outcomes Research: endorsed by the American Academy of Pediatrics. Circulation. 2009 Mar 24. 119(11):1541-51. [Medline].
- Thornhill MH, Dayer MJ, Forde JM, et al. Impact of the NICE guideline recommending cessation of antibiotic prophylaxis for prevention of infective endocarditis: before and after study. BMJ. 2011 May 3. 342:d2392. [Medline]. [Full Text].
A young adult with a history of intravenous drug use diagnosed with right-sided staphylococcal endocarditis and multiple embolic pyogenic abscesses on chest radiograph.
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