Childhood pneumonia: clinical features

It is not possible to distinguish between bacterial and viral pneumonia on clinical grounds alone!

Suggestive of bacteria:• Rapid onset (tachypnea, cough, retractions)• Likely to appear very sick• Higher temperatures (>39º C)

Suggestive of virus:• Low-grade fever, irritable but not toxic (usually!)• Associated complaints: HA, sore throat, myalgias, GI complaints• Longer prodrome (2-3 days or longer)• Concomitant URI symptoms at times

Indications for hospitalization in pediatric pneumonia

• Considered for most infants <4 months of age (unless viral etiology/Chlamydia trachomatis and child relatievly asymptomatic)

• Hypoxemia (oxygen saturation <92%)• Dehydration, poor oral intake• Moderate to severe respiratory distress: RR> 70 breaths/min in infanst <12

months or >50 breaths/min in older children, difficulty breathing, apnea, grunting

• Toxic appearance (tends to be more common with bacterial etiologies)• Underlying conditions predisposing to a more serious course

(cardiopulmonary disease, immunocompromised, metabolic disorders)• Presence of complications – effusions/empyema• Failure of outpatient therapy (worsening or no response in 24-72 hours)

Indications for treatment in an intensive care unit in pediatric pneumonia

• Failure to maintain O2 saturation >92% in FiO2 >0.5-0.6• Signs of impending respiratory failure (lethargy, increasing work of

breathing, and/or fatigue with or without hypercarbia)• Recurrent apneic episodes or slow, irregular respirations• Cardiovascular compromise with progressive tachycardia and/or

hypotension

Pediatric Community-acquired pneumonia: Etiologic agents

Birth to 20 day• Group B streptococci• Gram-negative enteric bacilli• Cytomegalovirus• Listeria monocytogenes• Viruses

3 weeks to 3 months• Chlamydia trachomatis• Respiratory syncytial virus • Parainfluenza virus • Streptococcus pneumoniae• Bordetella pertussis• Staphylococcus aureus• Viruses (metapneumoivrus, adenovirus, influenza virus, rhinovirus, others)

Pediatric Community-acquired pneumonia: Etiologic agents

Prechool• Streptocccus pneumoniae• Viruses • Mycoplasma pneumoniae• Staphylococcus aureus (including MRSA)5 to 15 years• Mycoplasma pneumoniae• Chlamydophila pneumoniae• Streptocccus pneumoniae• Viruses • Staphylococcus aureus (including MRSA)

Remember to consider tuberculosis, endemic fungal disease (histoplamosis), aspiration pneumonitis, Pneumocystis jiroveci, pertussis, CMV, and other etiologic agents in

certain age groups and in specific clinical settings!

Childhood pneumonia: clinical features

Suggestive of Mycoplasma pneumoniae• Older children• Multiple organ systems may also be involved• Rapid and progressive disease in sickle cell anemia

Suggestive of Chlamydia trachomatis (in young infant):• Afebrile pneumonia with tachypnea and crackles• May be associated with conjunctivitis, FTT

Diagnosis of pediatric pneumonia

Bacteria - WBC count & leukocytosis ,blood cultures (3%-11% in pneumonia),

CRP, ESR; “sputum “ (Gram stain and culture), urine pneumococcal

antigen (good sensitivity, poor specificity)

Viral - viral isolation, antigen detection, molecular diagnostics, serology

limited.

Mycoplasma – serology (IgM has poor specificity ~60%), paired serology,

PCR (limited sensitivity in children; poor sputum sample)

Chlamydophila – Serology (poor sensitivity , limited specificity in children),

Legionella – Urinary antigen (sensitivity ~80%, specificity ~100%)

Radiology – to follow.

“… we have found that studies assessing the diagnostic accuracy of clinical, radiological, and laboratory tests for bacterial childhood pneumonia have used a heterogeneous group of gold standards, and found, at least in part because of this, the index tests have widely different accuracies. These findings highlight the need for identifying a widely accepted gold standard for diagnosis of bacterial pneumonia in children.”

Lynch T, et al. A systematic review on the diagnosis of pediatric bacterial pneumonia: When gold is bronze. Plos ONE 2010; 5(8): e11989. doi:10.1371/journal.pone.0011989

Michelow IC, et al. Pediatrics 2004; 113:701-707

Michelow IC, et al. Pediatrics 2004; 113:701-707

Michelow IC, et al. Pediatrics 2004; 113:701-707

Michelow IC, et al. Pediatrics 2004; 113:701-707

Parenteral empiric antibiotics for inpatient treatment of pediatric pneumonia

Remember: Most community-acquired pneumonia in children <5 years is caused by a virus!

Age group Empiric regimen

Birth to 3 weeks

Bacteria – Group B streptococcus, Ampicillin 200mg/kg/d + gentamicin 5 mg/kg/d

gram-negative bacilli and/or cefotaxime 150 mg/kg/d

3 weeks to 4 months

Bacterial Cefuroxime (100-150 mg/kg/d in three

divided doses), or

Ceftriaxone (50-75 mg/kg once daily), or

Cefotaxime (150-200 mg/kg/d in three or

four divided doses)

Chlamydia trachomatis Erythromycin (40 mg/kg/d in four divided

doses), or

Azithromycin (5 mg/kg once per day)

Parenteral empiric antibiotics for inpatient treatment of pediatric pneumonia

Age group Empiric regimen

>4 months

Bacterial (not Mycoplasma or Ampicillin 150-200 mg/kg/d div qid. or

Chlamydophila pneumoniae) Cefuroxime (100-150 mg/kg/d in three divided doses [Max 4-6 g/d), or

Ceftriaxone (50-75 mg/kg once daily [MAX

4 gm/d]), or

Cefotaxime (150-200 mg/kg/d in three or

four divided doses [MAX 8-10g/d])

Mycoplasma or C. pneumoniae Erythromycin (40 mg/kg/d in four divided

doses [MAX 4g/d]), or

Azithromycin (5 mg/kg once per day [MAX 500

mg/d]), or

Doxycycline 4 mg/kg/d in two divided doses

[MAX 200 mg/d]) – in children >8 years

Treatment of severe community-acquired bacterial pneumonia

Suspect MRSA in:

“Patients with severe pneumonia,

particularly during influenza season,

in patients with cavitary infiltrates,

and in those with a history of MRSA infection”

Treatment:

Vancomycin or linezolid should be used in such patients

Med Lett Drugs Ther 2007; 49(1266):62-64

Empiric antibiotics for treatment of severe pneumonia

Moderately severe (non-ICU) pneumonia:

Erythromycin, or azithromycin, or doxycycline

PLUS

Ceftriaxone or cefotaxime

Complicated pneumonia/abscess/effusion or severely ill patients requiring ICU admission:

Ceftriaxone or cefotaxime

PLUS

Vancomycin (trough levels 15-20 ug/mL) or ? clindamycin

PLUS

Azithromycin

PLUS (if necessary)

Nafcillin

Duration of therapy in pediatric pneumonia

• Few evidence-based data to guide duration of therapy• Parenteral: Generally preferable to switch to oral antimicrobial therapy in

patients who have received IV medications if (a) afebrile for 24-48 hours and (b) able to keep food down.

• Uncomplicated cases: 7-10 days combined IV/PO for routine pathogens in uncomplicated infection.

• Consider continuing PO therapy until one week beyond resolution of fever• Complicated cases: Necrotizing pneumonia or abscess – likely 4 weeks and

patient improving.

Su-Ting T, Tancredi D. Empyema hospitalizations increased in US children despite pneumococcal conjugate vaccine. Pediatrics 2010; 125:26-33.

Byington CL, et al.J Clin Microbiol 2010; 48:520-525

Parapneumonic effusion and empyema in children –organisms

• Streptococcus pneumoniae – most common pathogen• Penicillin-susceptible• Penicillin non-susceptible• Pneumococcal-conjugate vaccine impact

• Staphylococcus aureus• Methicillin-resistant (MRSA)• Methicillin-susceptible

• Group A streptococcus (Streptococcus pyogenes ), others (in immunocompromised, neonates)

• R/O non-infectious etiologies

Critical laboratory evaluation: pleural fluid analysis, other microbial analyses, blood cultures, other testing dependent on clinical scenario

Antibiotic therapy in therapy in complicated pediatric pneumoniaa, parapneumonic effusion and empyema

Ceftriaxone (50 to 100 mg/kg once daily [MAX 4 g/day]) or cefotaxime (150 to 200 mg/kg per day in three to four divided doses [MAX 8 to 10 g/day])

PLUS

Clindamycin (30 to 40 mg/kg per day in three or four divided doses [MAX 1 to 2 g/day])

OR, for patients very ill and suspect MRSA or allergic to clindamycin

Vancomycin (60 mg/kg per day in four divided doses [MAX 2 to 4 g/day])

Might need to cover atypical pathogens in some cases. Modify antibiotic therapy based on culture/microbiologic results when available.

a necrotizing process

Effective Therapy for Serious Infections Caused by MRSA

Vancomycin– Glycopeptide antibiotic– Inhibits bacterial cell wall synthesis by high-affinity binding to cell

wall precursors.– Therapeutic blood level monitoring– VISA, VRSA – IV preparation only

Linezolid– Oxazolidinone antibiotic– Interferes with formation of bacterial ribosomal initiation complex to

prevent activation of protein synthesis.– Available in both intravenous and oral preparations– Expensive

Vancomycin Clinical Failure Rates inMRSA Infections

n = 63 patients with MRSAtreated with vancomycin

Moise-Broder et al. Clin Infect Dis 2004; 38:1700-05