Native Valve Endocarditis in Children - ( i.e. No Intra-Cardiac Prosthetic Material )
|Publication: 01/12/2010 --|
|Last review: 06/12/2018|
|Next review: 01/12/2021|
|Approved By: Improving Antimicrobial Prescribing Group|
|Copyright© Leeds Teaching Hospitals NHS Trust 2018|
This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
Guideline for the Management of Native Valve Endocarditis in Children (i.e. No Intra-Cardiac Prosthetic Material)
Native Valve Endocarditis in Children
This guideline applies to children with suspected or confirmed native valve endocarditis (NVE) [i.e. when no intra-cardiac prosthetic material is present.]
Consider NVE in children with any of the following:
Urgent empirical therapy: intravenous Flucloxacillin 50mg/kg/dose (max. 2grams) 6-hourly and Gentamicin 2mg/kg/dose (max. 100mg) 12hourly* dose adjustments will be necessary according to creatinine clearance.
*Low-dose Gentamicin is for synergistic activity; pre-dose levels should be maintained <1mg/L and 1 hour post-dose levels 3-5mg/L
See full guideline for treatment of specific organisms
Infective endocarditis can affect any part of the endocardium but most commonly involves heart valves. Native valve endocarditis [NVE] is a term used to describe infection of a native [or natural] heart valve in the absence of any prosthetic material. Congenital as well as acquired cardiac lesions can predispose to endocarditis. The pathological lesion of endocarditis is the vegetation a mixture of microorganisms and host-derived products such as platelets and fibrin, essentially an infected coagulum.
The most common cause of NVE is bacterial infection. Streptococci, staphylococci and enterococci remain the most common aetiological agents, but the list of potential pathogens is long.1
Clinical manifestations of endocarditis are varied and result from various infection-related pathological processes:
Infective endocarditis was universally fatal in the pre-antibiotic era. In the modern era it is managed with either antimicrobial agents alone, or in combination with surgery, and in-hospital mortality is approximately 5-10%.1,2 The necessity for prolonged antimicrobial therapy to achieve a cure was established early in the history of antimicrobial use when relapse was more common when short courses of treatment were employed. There are few randomized controlled trials on which to base recommendations, but there is plenty of observational evidence and expert opinion. Many of the recommendations summarized herein come from existing published guidelines.3-6
Recommendation: Three sets of blood cultures should be taken at different times, ideally 6 hours a part during the first 24 hours in all patients with suspected native valve endocarditis and no features of severe sepsis, according to Standard operating procedure.3 (Evidence level C)
Recommendation: When antimicrobials have been given prior to admission, blood cultures should be taken as recommended above. If the patient is clinically stable without signs of severe sepsis or septic shock and is not in heart failure antimicrobials should be withheld pending blood culture results. If initial blood cultures are negative, a set of three further blood cultures should be taken after one week off antimicrobial therapy, or sooner if there is recurrence of fever. (Evidence level C)
Recommendation: If the patient has severe sepsis or septic shock, two sets of blood cultures should be taken at different times in the first hour, during initial resuscitation before starting empirical therapy as outlined below. (Evidence level C)
Recommendation: If blood cultures are negative send clotted blood for Bartonella and Coxiella serology. (Evidence level B)
Blood cultures are a fundamental component of the diagnosis of endocarditis and are positive in 95% of cases.9 In order to demonstrate a sustained bacteraemia and because bacteria that are known to be common blood culture contaminants can also cause endocarditis [e.g. coagulase negative staphylococci and propionibacteria] multiple blood culture sets are required. Three sets of blood cultures will give a microbiological diagnosis 95% of the time.9
Recommendation: Echocardiography should be performed in all cases where there is a clinical suspicion of endocarditis.3
Recommendation: TTE is the initial method of assessment recommended for NVE.3
TTE has been shown to have 86% sensitivity in detection of echocardiographic markers of endocarditis with a specificity of 93% in detection of vegetations.10 (Evidence level B)
Recommendation: TOE may be required in selected cases (e.g. young adults) where TTE is inadequate especially to visualise posterior structures, prosthetic valves and areas of heavy calcification.
Cardiac ultrasound (echocardiography) is a fundamental investigative tool in the diagnosis of endocarditis. The Duke criteria have been formulated around the demonstration of i) persistent bacteraemia and ii) demonstration of an area of infected endocardium, which is most commonly a heart valve. In adults, the aortic and mitral valves are almost equally involved, followed by the tricuspid and very rarely the pulmonary valve. Echocardiography serves to confirm the presence of an at-risk heart valve lesion or other structural abnormality.11 It may demonstrate the pathological lesion of endocarditis, a vegetation or infected coagulum. A vegetation is defined as a mobile echodense mass attached to valve leaflets or the mural endocardium. Other echocardiographic features of endocarditis are periannular abscess formation, new valvular regurgitation and new dehiscence of a valvular prosthesis.8,11 Echocardiography can also indicate the degree of heart valve damage and its haemodynamic effect. Additionally, it provides an assessment of ventricular function. In children echocardiography is usually carried out using a probe on the chest wall (transthoracic or surface echocardiography, TTE). Adolescents and young adults may require a transoesophageal echocardiogram (TOE) with a probe positioned in the oesophagus.
It should be noted that vegetations can persist after successful treatment of NVE, highlighting the fact that positive echocardiographic identification of vegetation does not have 100% specificity for a diagnosis of NVE. Also, vegetations may not be detected on echocardiography even in the presence of clinically and microbiologically proven infective endocarditis. Therefore an echocardiogram is not the definitive diagnostic tool in endocarditis.
Recommendation: An electrocardiogram (ECG) should be performed at baseline, if conduction disturbances are suspected and at weekly intervals in patients with aortic valve involvement.
Recommendation: FBC should be measured at baseline and repeated weekly during therapy unless there is a clinical indication for more frequent testing.
The peripheral white blood cell count may be normal or elevated in patients with native valve endocarditis and is therefore not particularly useful in confirming a clinical diagnosis.12 A full blood count (FBC) is indicated however to determine if the patient is anaemic and to establish a baseline peripheral white blood cell count since several of the antimicrobials used in treatment can cause leukopenia.
Recommendation: CRP should be measured at baseline and weekly during therapy.
C-reactive protein (CRP) is a sensitive test, being raised in >95% of patients with endocarditis,12 but it is non-specific. A raised CRP provides supportive evidence of infection, rather than confirming the diagnosis, and can be used to monitor response to treatment.12,13
Recommendation: U&E and LFTs should be measured at baseline and weekly during therapy (or more frequently if renal function is unstable).
Urea and electrolytes (U&E), liver function tests (LFTs) are necessary baseline tests. Results will influence choice and dose of antimicrobials as well as fluid balance, nutritional support etc.
Recommendation: A urine sample should be sent for microscopy and culture if the dipstick test is positive for leukocytes and nitrites or red blood cells.
Urinalysis is indicated at baseline because the presence of haematuria can help to confirm a diagnosis of endocarditis.7
When a fungal infection is suspected, a clotted blood sample for Candida antibodies is no longer advised
All children being treated with antibiotics for confirmed infective endocarditis will need to be transferred to the tertiary cardiac centre (Children’s Yorkshire Heart Centre, Leeds General Infirmary) for ongoing care. This is because infective endocarditis still carries a significant mortality and morbidity and requires close monitoring with specialist cardiac investigations during treatment.
Ideally, patients should be reviewed and examined daily.
Particular attention during the examination should be given to any changes in the auscultatory findings, especially, new onset or worsening valve regurgitation or symptoms and signs of congestive heart failure.
Embolisation occurs in 20% of cases2,14 with majority involving and 65%the central nervous system, particularly to the middle cerebral artery. The risk of embolisation is highest in the first 14 days after diagnosis.
Recommendation: If intra-cranial lesions are detected the case should be discussed urgently with the Paediatric neurosurgical team on-call.
Recommendation: In patients with a relapse of fever consider loss of control of the infection with current antimicrobial therapy or the development of a new site of infection (e.g. intravascular catheter related infection, splenic abscess formation)
Recommendation: In patients with a relapse of fever consider also the possibility of antimicrobial allergy.
Recommendation: Peripheral cannulae should be used in preference to a central venous route in the first 48 hours unless there is a clear indication to use the latter route. Ideally obtaining a PICC line or another non-cuffered CVC would be the preferred option in children, once the diagnosis and treatment course has been established.
Recommendation: Full aseptic technique should be used when any venous access device is inserted and during subsequent handling for the administration of drugs.
Recommendation: Peripherally inserted central venous cannulae (PICC) are preferred to subcutaneously-tunnelled central lines (e.g. Hickman lines) for delivery of long-term antibiotics. Specific attention should be paid to the site of line insertion particularly in children with complex congenital heart disease so as not to jeopardise veins that may need to be used for future diagnostic and interventional strategies.
Recommendation: If a central line is to be inserted then this should ideally be a single lumen device dedicated to administration of antimicrobials.
Recommendation: The Paediatric Cardiothoracic Surgical Consultant on-call should be made aware of patients with confirmed infective endocarditis who are likely to need surgical intervention so that the lines of communication and referral are clearly established.6
The indications for surgical treatment are:
The timing of surgery will be determined on an individual basis.
|Empirical Antimicrobial Treatment|
Recommended urgent empirical therapy: intravenous Flucloxacillin 50mg/kg/dose (max. 2grams) 6-hourly and Gentamicin 2mg/kg/dose (max. 100mg) 12-hourly * dose adjustments will be necessary if there is renal impairment
*Low-dose Gentamicin is for synergistic activity; pre-dose levels should be maintained <1mg/L and 1 hour post-dose levels 3-5mg/L.
*dose adjustments will be necessary if there is renal impairment or renal failure. (Evidence level D)
A microbiological diagnosis enables administration of directed antimicrobial therapy, avoiding the need for broad-spectrum, potentially toxic therapeutic combinations or erroneous empirical therapy. Outcomes are better if the pathogen is known. In patients who have been administered antimicrobials before blood cultures have been taken, the chance of obtaining a microbiological diagnosis is reduced, highlighting the need to withhold treatment until appropriate investigations have been carried out. Antimicrobials should not be started until after blood cultures have been taken (see blood culture section above). On occasion, alternatives to Vancomycin might be needed because of allergy, intolerance or renal function, in this situation, daptomycin is the preferred alternative (and should be discussed with microbiology).
Recommendation: Empirical antimicrobial therapy for a patient with clinical and echocardiographic findings suggestive of endocarditis but who is clinically stable and has negative blood cultures should be discussed with microbiology on a case-by-case basis.
|Directed Antimicrobial Treatment (when microbiology results are known)|
Specific recommendations can be made for a number of organisms causing NVE.
Genuine Penicillin Allergy; use regimen for methicillin-resistant staphylococci.
For methicillin-resistant staphylococci: a combination of intravenous Vancomycin * 15mg/kg/dose 6hourly (max. 3grams in 24 hours) with oral or intravenous Rifampicin 10mg/kg/dose (max. 600mg) 12hourly is recommended.
NB. For staphylococci that are resistant to Vancomycin , or if an alternative is needed because of allergy, intolerance or renal function, Daptomycin is the preferred alternative (and should be discussed with microbiology).
For streptococci with reduced susceptibility to penicillin (MIC >0.125 -≤0.5mg/L): intravenous Benzyl penicillin 50mg/kg/dose (max. 2.4gram) 4-hourly is recommended together with intravenous Gentamicin# 2mg/kg/dose (max. 100mg) 12-hourly for the first 2 weeks.
For streptococci with reduced susceptibility to penicillin (MIC >0.5): intravenous Vancomycin 15mg/kg/dose 6 hourly (max. 3grams in 24hours) with intravenous Gentamicin# 2mg/kg/dose (max. 100mg) 12-hourly for the first 2 weeks. (Evidence level C)
Genuine Penicillin Allergy; use the regimen for Amoxicillin-resistant enterococci.
For Amoxicillin-resistant enterococci: a combination of intravenous Vancomycin * 15mg/kg/dose 6-hourly (max. 3 grams in 24hours) with intravenous Gentamicin# 2mg/kg (max. 100mg) 12-hourly is recommended.
*dose adjustments will be necessary if there is renal impairment or renal failure.
#Use Gentamicin with caution in patients with renal impairment. Gentamicin pre-dose levels should be maintained <1mg/L and 1 hour post-dose levels 3-5mg/L. Synergy may be lost in isolates with high-level resistance to Gentamicin.
HACEK group bacteria (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella): Cefotaxime 50mg/kg/dose (max. 3gram) 6 hourly OR Ceftriaxone 100mg/kg/dose (max. 4 gram) 24 hourly OR IV Amoxicillin 100mg/kg/dose (max. 2grams) 4-hourly +/- intravenous Gentamicin# 2mg/kg/dose (max. 100mg) 12-hourly may be appropriate depending on susceptibility.
Other organisms such as Enterobacteriaceae, Pseudomonas aeruginosa and fungi are uncommon and should be treated on a case-by case basis following discussion with Microbiology.
|Duration of Treatment|
Recommendation: In most instances, uncomplicated endocarditis affecting native cardiac structures i.e. no shunts, prostheses or conduits, should be treated with four weeks of intravenous antimicrobials. If the patients symptoms of infection have resolved; they are afebrile; and CRP is returning to normal (<30mg /L) after four weeks treatment, antimicrobials can be stopped.
Recommendation: The presence of a brain abscess, intracardiac abscesses or vertebral osteomyelitis usually requires treatment with six weeks antimicrobials.
|Switch to oral agent(s)|
Adjunctive therapy with agents with good bioavailability such as rifampicin can be given orally otherwise standard therapy for endocarditis requires intravenous therapy for the duration.
|Please contact Microbiology if the patient is not responding to the recommended antimicrobial regimens|
Native valve endocarditis in children
|Target patient group:||Children (>1 month old to <16 years) with suspected or confirmed native valve endocarditis|
|Target professional group(s):||Secondary Care Doctors
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- Yoshinaga M, Niwa K, Niwa A, et al. Risk factors for in-hospital mortality during infective endocarditis in patients with congenital heart disease. Am J Cardiol 2008; 101(1): 114-8.
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- Baddour LM, Wilson WR, Bayer AS, 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; 111(23): e394-434.
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- Olaison L, Hogevik H, Alestig K. Fever, C-reactive protein, and other acute-phase reactants during treatment of infective endocarditis. Arch Int Med 1997; 157(8): 885-92.
- McCartney AC, Orange GV, Pringle SD, Wills G, Reece IJ. Serum C reactive protein in infective endocarditis. Journal of Clinical Pathology 1988; 41(1): 44-8.
- K. Thom, A Hanslik, J L Russell, et al. Incidence of infective endocarditis and its thromboembolic complications in a pediatric population over 30 years. Int J Cardiol 2018:252: 74-9.
A. Meta-analyses, randomised controlled trials/systematic reviews of RCTs
B. Robust experimental or observational studies
C. Expert consensus.
D. Leeds consensus. (where no national guidance exists or there is wide disagreement with a level C recommendation or where national guidance documents contradict each other)
Improving Antimicrobial Prescribing Group
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