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Sharma J, Nagraj A, Allapathi D, Rajegowda B,
Leggiadro R. Fungal endocarditis in a premature infant complicated by a
right atrial mycetoma and inferior vena cava thrombosis. Images Paediatr
Cardiol 2009;41:6-11
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Division of Pediatric Cardiology, Neonatology and Infectious Disease, Department of Pediatrics, Lincoln Medical and Mental Health Center, 234, East 149th Street, Bronx, NY 11451 |
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| Neonatal candidemia | Endocarditis | Venous thrombosis |
| Mycetoma |
Background
Fungal endocarditis is a rare occurrence in premature infants with
more than 50% mortality and significant morbidity regardless type of treatment.1
Candida albicans accounts for two third of fungal endocarditis. Cardiac
involvement is found in 15.2% of neonates with candidemia and they usually
present with hypotension, bradycardia and acute respiratory distress requiring
intubation.2 Right atrial mycetoma (RAM) is reported in only
9% cases of fungal neonatal endocarditis3 and its management
is usually with prolonged use of antifungal therapy in association with
surgery in a select group of patients.
Case Report
A preterm male was born at 26 weeks of gestation with a birth weight
of 846g by emergency cesarean section for fetal heart rate anomalies and
breech presentation.
The newborn had severe respiratory distress syndrome and metabolic acidosis at birth. He was treated with intratracheal surfactant and placed on ampicillin and gentamicin after a sepsis work up. He was treated with ibuprofen on the fifth day of life for symptomatic patent ductus arteriosus. A few hours after the administration of ibuprofen, the baby developed abdominal distension with bluish discoloration and the abdominal x ray showed evidence of intestinal perforation. Antibiotic coverage was started and peritoneal drains were placed. Blood culture grew Pseudomonas aeruginosa and Candida albicans, while peritoneal culture grew Pseudomonas aeruginosa and Enterococcus fecalis. The baby was treated with imipenam and liposomal amphotericin. An ileostomy was done. An echocardiogram performed at this time showed no evidence of endocarditis. Renal sonogram and ophthalmologic evaluation were negative. Repeat blood cultures continued to grow candida despite liposomal amphotericin administered at a dose of 7mg/kg/day.
At 10 days of life, baby began to develop persistent thrombocytopenia requiring platelet transfusions. A Broviac line was placed in the left femoral vein for intravenous antibiotics and antifungal therapy. During the next two weeks, he received a total of 7 units of fresh frozen plasma and 10 units of platelets via this line due to persistent thrombocytopenia and low grade disseminated intravascular coagulation picture. The line was removed on the 24th day of life because of a leak around the insertion site suggestive of loss of patency. Culture of the tip was negative. Caspofungin was added because of persistent fungemia.
At 28 days of life, baby developed progressively worsening oliguria
and azotemia. Renal ultrasound showed bilateral abnormal renal echogenicity
with reversal of blood flow in both main renal arteries during diastole.
An echocardiogram revealed the cause of the renal failure, persistent fungemia
and persistent thrombocytopenia. This was a massive echogenic mass in the
right atrium extending from the inferior vena cava (Fig. 1).

The mass in the right atrium moved across the tricuspid valve in diastole
and was also in close proximity with the atrial communication (Figs 2 and
3).



Discussion
The reported incidence of candida infection in neonatal intensive care
units is about 1% but occurs in 4-15% of extremely low birth weight infants
(BW<1kg).1 A positive Candida culture for more than five
days is defined as persistent candidemia which is associated with increased
risk of endocarditis but not with other complications.2 Persistent
candidemia is often invasive in low birth weight premature infants. Ophthalmologic,
renal and cardiac evaluations are routinely done as baseline and should
be repeated based upon the clinical course as such complications may influence
therapy and outcome.1 Independent of birth weight, infants born
at less than 26 weeks or who had abdominal surgery are at a significantly
increased risk of candidemia.
The occurrence of fungal endocarditis is on the rise, reported in last decade in infants and children secondary to use of central venous line (CVL), prolonged use of broad spectrum antibiotics and neonatal cardiac surgery.4 CVL is frequently used in supportive care of premature infants for fluids, prolonged antimicrobial therapy and total parenteral nutrition (TPN). Several possible mechanisms by which CVL causes thrombosis include damage to vessel walls, disrupted blood flow, infusion of substances such as TPN that damage endothelial cells and thrombogenic catheter materials. An increased incidence of venous thrombosis is reported with femoral-subclavian CVL compared to brachial –jugular CVL and it does not depend on choice of type, size and duration of CVL.5 A Broviac was placed in left femoral site in our patient due to technical difficulties in the neck and upper extremity. Repeated infusion of platelets to treat persistent thrombocytopenia through this line may have led to local thrombus formation which gradually extended into the inferior vena cava affecting renal blood flow, causing progressive renal failure. Intravascular thrombus was likely seeded with fungus and led to persistent candidiasis for more than three weeks. The clot from the inferior vena cava extended in to the right atrium and became the harbinger of underlying extensive venous thrombosis.
Liposomal amphotericin is generally first line of therapy. Fluconazole is a fungistatic drug, often used in combination with amphotericin in non-neutropenic patients as well in cases of right atrial mycetoma (RAM).6 There is limited data available for the use of caspofungin in cases of fungal endocarditis. Empirical antifungal therapy is recommended in newborns aged less than 25 weeks of gestation, thrombocytopenia and exposure to third generation cephalosporins 7 days prior to blood culture due to the high incidence of mortality and morbidity in this group.7 An active effort should be made to remove CVL in the presence of persistent fungemia. Surgery has a role in a select group of neonates with RAM. Depending upon its size and location, RAM may cause hemodynamic compromise with obstruction of tricuspid inflow and potential for embolism.8 The outcome of RAM is comparable with both medical and surgical treatment.3,6,8
Persistent candidemia in low birth weight premature infants is a risk
factor for endocarditis and demands a thorough and repeated search for
a nidus and end organ complications related to the heart, central nervous
system and kidneys. RAM complicates the management of fungal endocarditis
in the newborn. Despite advances in antifungal agents and cardiac surgical
interventions, fungal endocarditis still carries high mortality and morbidity.
References
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