Practice Essentials
Hospital-acquired infections are caused by viral, bacterial, and fungal pathogens; the most common types are bloodstream infection (BSI), pneumonia (eg, ventilator-associated pneumonia [VAP]), urinary tract infection (UTI), and surgical site infection (SSI).
Risk factors for catheter-associated BSI in neonates include the following
:
Catheter hub or exit-site colonization
Catheter insertion after the first week of life
Duration of parenteral nutrition
Extremely low birth weight (< 1000 g) at catheter insertion
In the pediatric ICU, neutropenia, prolonged catheter dwell time (>7 days), percutaneously placed central venous lines, and frequent manipulation of lines have been identified as risk factors for catheter-associated BSI
Risk factors for candidemia in neonates include the following
:
Gestational age of less than 32 weeks
5-minute Apgar scores below 5
Shock, disseminated intravascular coagulation
Prior intralipid use
Parenteral nutrition, central venous line placement
H2 blocker administration
Intubation
Hospital stay longer than 7 days
Risk factors for VAP in pediatric patients include the following
:
Reintubation
Genetic syndromes
Immunodeficiency, immunosuppression
Prior BSI
Risk factors for hospital-acquired UTI in pediatric patients include the following
:
Bladder catheterization
Prior antibiotic therapy
Cerebral palsy
The source of infection may be suggested by the instrumentation, as follows:
Endotracheal tube: Sinusitis, tracheitis, pneumonia
Intravascular catheter: Phlebitis, line infection
Foley catheter: UTI
Patients with pneumonia may have the following:
Fever, cough, purulent sputum
Abnormal chest auscultatory findings (eg, decreased breath sounds, crackles, wheezes)
Patients with UTI may have the following:
Fever or normal temperature
Tenderness, suprapubic (cystitis) or costovertebral (pyelonephritis)
Cloudy, foul-smelling urine
See Clinical Presentation for more detail.
Diagnosis
Because not all bacterial or fungal growth on a culture is pathogenic and because such growth may reflect simple microbial colonization, interpretation of cultures should take into account the following:
Clinical presentation of the patient
Reason for obtaining the test
Process by which the specimen was obtained
Presence or absence of other supporting evidence of infection
Methods used to diagnose and characterize BSIs include the following:
Suspected catheter-associated BSI: Differential time to positivity of paired blood cultures (simplest)
; quantitative culture of blood obtained from the catheter and peripheral vein; quantitative culture of catheter segment
Suspected fungal infection: Fungal cultures, detection of (1,3)-β-D-glucan and galactomannan
Possible thrombosis or vegetations: Imaging studies such as echocardiography
Immunocompromised patients: Occasional special studies (eg, cultures for Nocardia, atypical mycobacteria, cytomegalovirus [CMV], and CMV antigenemia)
Tests used to identify pneumonia include the following:
Acute-phase reactants
Oxygen saturation and hemodynamic studies
Chest radiography
Sputum Gram stain and culture (if necessary, samples can also be obtained through bronchoalveolar lavage or thoracocentesis)
Rapid diagnostic tests (eg multiplex PCR capable of identifying multiple pathogens in a specimen)
Urinalysis and urine culture, along with clinical findings, are essential for differentiating between asymptomatic bacteriuria, cystitis, and pyelonephritis. The following factors should be kept in mind in the interpretation of urine cultures:
Number of colonies and species isolated
Method of sample collection
Time from collection to laboratory processing
Sex of the patient
Previous antibiotic use
Most experts recommend imaging studies in evaluating children with first-time UTI.
See Workup for more detail.
Management
Medical care includes supportive care addressing shock, hypoventilation, and other complications, along with empiric broad-spectrum antimicrobial therapy.
Management of BSI may include the following:
Line removal as appropriate
Antibiotic therapy covering gram-positive and gram-negative organisms, started empirically and then tailored according to specific susceptibility patterns
Antifungal therapy as appropriate
Antiviral therapy as appropriate
Prevention through use of catheter disinfection caps
Management of pneumonia includes the following:
Initial empiric broad-spectrum antibiotic therapy, later streamlined on the basis of identified organisms and susceptibilities, with attention to the risk of multidrug-resistant (MDR) pathogens
Antiviral medications against influenza for symptomatic patients and patients with immunodeficiency or chronic lung diseases to limit morbidity and mortality
Management of UTI includes the following:
Removal of indwelling catheters if possible
Empiric antibiotic and antifungal therapy
Management of SSI includes the following:
Surgical debridement
Antibiotic therapy
See Treatment and Medication for more detail.