François Boucher MD, FRCPC Community acquired pneumonia (CAP): Why is this still a problem?

François Boucher MD, FRCPC

Community acquired pneumonia (CAP): Why is this still a problem?

Objectives

After this presentation, participants will be able to:

• Determine appropriate agents, routes and duration of treatment.

• Recognize how local epidemiology influences treatment choices.

• Manage complications of CAP.

Emergent problems in pediatric community-acquired pneumonia

•Severe pneumonia

• Pulmonary abscess formation: GAS

• Pulmonary necrosis & fibrosis: MRSA

• Pneumatocoeles: S. aureus

• Resistant organisms: S. pneumoniae 19A

•Parapneumonic effusion

• Increasing incidence

• Difficult management

IDSA Pediatric Community Pneumonia Guidelines. CID 2011;53:e25

Incidence in Canadian children

•41,000 children <5 years of age treated in the community each year

•9600 hospitalized

•older children have decreased incidence

•leading cause of mortality and morbidity amongst Canadian Inuit; 1999-2000- outbreak in several communities on Baffin Island (adult and child)

Pathogens

•CAP generally caused by a single organism

•Even with extensive diagnostic testing, most investigators cannot identify a specific etiology for CAP in ≥ 50% of patients.

•In those identified, S. pneumoniae is causative pathogen 60-70% of the time

Pathogens in pediatric CAP

Pediatr Infect Dis J 2002 21: 592-598

Pneumococcal pneumonia

•Most common cause of CAP

•Gram positive diplococci

• “Typical” symptoms (e.g. malaise, shaking chills, fever, pleuritic hest pain, cough)

•Lobar infiltrate on CXR

•Rarely bacteremic in children

Atypical Pneumonia

•Second most frequent cause (especially in younger population)

•Commonly associated with milder symptoms: subacute onset, non-productive cough, no focal infiltrate on CXR

• Mycoplasma: younger Pts, extra-pulmonary symptoms (URI, rash), headache, sore throat

•Chlamydia pneumoniae: young adults, year round, URI, sore throat

Viral Pneumonia

•Most common cause in children

• RSV, influenza, parainfluenza

•Influenza is the most important viral cause in adults, especially during winter months

•Post-influenza pneumonia (secondary bacterial infection)

• S. pneumo, Staph aureus

Other bacteria

•Staphylococcus aureus

• Severe disease, prior viral pneumonia

•Gram negative bacteria

• Klebsiella – neonates

• Branhamella catarrhalis - sinus disease, otitis, COPD

• H. influenzae - Rare

•Anaerobes

• Aspiration pneumonia, dental disease

Clinical Features of C. Trachomatis Pneumonia

•Onset at 3 to 11 wks of age

•Cough greater than one week in duration

•Prior conjunctivitis

•Afebrile tachypnea with diffuse rales

•Hyperinflation and interstitial infiltrates on chest film

•Eosinophilia

•Increased IgM

•Increased IgA and IgG

Management of CAP:When to obtain a CXR

•Child < 5 years of age with high fever and high WBC of uncertain source

•Ambigusous clinical findings

•Suspected complication, i.e. pleural effusion

•Pneumonia is prolonged and unresponsive to treatment

Management of CAP:Considerations for admission

•Child aged less than 6 months of age

•Toxic appearance

•Severe respiratory difficulty

•TcSaO2 < 95%

•Dehydration, vomiting

•No response to oral medication

•Immunocompromised child

•Social circumstances / poor compliance

Management of CAP: Antibiotic therapyChild < 5 years old

•Presumed bacterial pneumonia

• Amoxicillin, oral (90 mg/kg/day in 2 doses) Alternative: oral amoxicillin clavulanate (amoxicillin component, 90 mg/kg/day in 2 doses)

•Presumed atypical pneumonia

• Azithromycin oral (10 mg/kg on day 1, followed by 5 mg/kg/day once daily on days 2–5);

• Alternatives: oral clarithromycin (15 mg/kg/day in 2 doses for 7-14 days) or oral erythromycin (40 mg/kg/day in 4 doses)


Management of CAP: Antibiotic therapyChild ≥ 5 years old


• Oral amoxicillin (90 mg/kg/day in 2 doses to a maximum of 4 g/day); for children with presumed bacterial CAP who do not have clinical, laboratory, or radiographic evidence that distinguishes bacterial CAP from atypical CAP, a macrolide can be added to a b-lactam antibiotic for empiric therapy;

• alternative: oral amoxicillin clavulanate (amoxicillin component, 90 mg/kg/day in 2 doses to a maximum dose of 4000 mg/day, eg, one 2000-mg tablet twice daily)


Management of CAP: Antibiotic therapyChild ≥ 5 years old


• Oral azithromycin (10 mg/kg on day 1, followed by 5 mg/kg/day once daily on days 2–5 to a maximum of 500 mg on day 1, followed by 250 mg on days 2–5); alternatives: oral clarithromycin (15 mg/kg/day in 2 doses to a maximum of 1 g/day); erythromycin, doxycycline for children >7 years old


Management of CAP: Antibiotic therapyInpatient (All ages)


• Ampicillin or penicillin G;

• alternatives: ceftriaxone or cefotaxime;

• addition of vancomycin or clindamycin for suspected CA-MRSA


Management of CAP: Antibiotic therapyInpatient (All ages)


• Azithromycin (in addition to ß-lactam, if diagnosis of atypical pneumonia is in doubt);

• alternatives: clarithromycin or erythromycin; doxycycline for children >7 years old; levofloxacin for children who have reached growth maturity, or who cannot tolerate macrolides


Management of CAP: Antibiotic therapyNot completely immunized

•Presumed bacterial pneumonia:

• Ceftriaxone or cefotaxime; addition of vancomycin or clindamycin for suspected CA-MRSA;

• alternative: levofloxacin; addition of vancomycin or clindamycin for suspected CA-MRSA


Management of CAP: Antibiotic therapyNot completely immunized


• Azithromycin (in addition to ß-lactam, if diagnosis in doubt);

• alternatives: clarithromycin or erythromycin; doxycycline for children >7 years old; levofloxacin for children who have reached growth maturity or who cannot tolerate macrolides


Management of CAP: Antibiotic therapyMild case or step-down therapy

•Preferred: amoxicillin (90 mg/kg/day in 2 doses or 45 mg/kg/day in 3 doses);

•Alternatives: second- or third-generation cephalosporin (cefpodoxime, cefuroxime, cefprozil); oral levofloxacin, if susceptible (16–20 mg/kg/day in 2 doses for children 6 months to 5 years old and 8–10 mg/kg/day once daily for children 5 to 16 years old; maximum daily dose, 750 mg) or oral linezolid (30 mg/kg/day in 3 doses for children <12 years old and 20 mg/kg/day in 2 doses for children ≥12 years old)


Management of CAP: Antibiotic therapyParenteral therapy

•Preferred: ampicillin (150–200 mg/kg/day every 6 hours) or penicillin (200 000–250 000 U/kg/day every 4–6 h);

•Alternatives: ceftriaxone (50–100 mg/kg/day every 12–24 hours) (preferred for parenteral outpatient therapy) or cefotaxime (150 mg/kg/day every 8 hours);

•may also be effective: clindamycin (40 mg/kg/day every 6–8 hours) or vancomycin (40–60 mg/kg/day every 6–8 hours)


Management of CAP: Antibiotic therapyHighly resistant S.pneumoniaeParenteral therapy

•Preferred: ceftriaxone (100 mg/kg/day every 12–24 hours);

•Alternatives: ampicillin (300–400 mg/kg/day every 6 hours), levofloxacin (16–20 mg/kg/day every 12 hours for children 6 months to 5 years old and 8–10 mg/kg/day once daily for children 5–16 years old; maximum daily dose, 750 mg), or linezolid (30 mg/kg/day every 8 hours for children <12 years old and 20 mg/kg/day every 12 hours for children ≥12 years old);

•may also be effective: clindamycin (40 mg/kg/day every 6–8 hours) or vancomycin (40–60 mg/kg/day every 6–8 hours)


Management of CAP: Antibiotic therapyHighly resistant S.pneumoniaeOral therapy

•Preferred: oral levofloxacin (16–20 mg/kg/day in 2 doses for children 6 months to 5 years and 8–10 mg/kg/day once daily for children 5–16 years, maximum daily dose, 750 mg), if susceptible, or oral linezolid (30 mg/kg/day in 3 doses for children <12 years and 20 mg/kg/day in 2 doses for children ≥12 years);

•Alternative: oral clindamycin (30–40 mg/kg/day in 3 doses)


Levofloxacin (Levaquin™)

•Wide-spectrum fluoroquinolone:• S pneumoniae,• Haemophilus influenzae (nontypeable),• Moraxella catarrhalis• M pneumoniae, C pneumoniae, Legionella• M. tuberculosis

•Excellent bioavailability: 100% absorbed•Well tolerated by children

• 5-year safety study reported 11-03-23•Many interactions

• Medications: anticoagulants• Natural products

Linezolid (Zyvox™)

•Narrow-spectrum oxazolidinone: Gram+

• S pneumoniae,

• S. aureus, MRSA

• VRE

•Excellent bioavailability: ≈100% absorbed

•Well tolerated for short courses of therapy

• Headache, diarrhea, nausea

• Long-term use: Bone marrow suppression, thrombocytopenia

• > 2 weeks: neuropathy, lactic acidosis, mitochondrial toxicity

Management of CAP: Antibiotic therapyGroup A StreptococcusParenteral therapy

•Preferred: intravenous penicillin (100 000–250 000 U/kg/day every 4–6 hours) or ampicillin (200 mg/kg/day every 6 hours);

•Alternatives: ceftriaxone (50–100 mg/kg/day every 12–24 hours) or cefotaxime (150 mg/kg/day every 8 hours);

•may also be effective: clindamycin, if susceptible (40 mg/kg/day every 6–8 hours) or vancomycin (40–60 mg/kg/day every 6–8 hours)


Management of CAP: Antibiotic therapyGroup A StreptococcusOral therapy

•Preferred: amoxicillin (50–75 mg/kg/day in 2 doses), or penicillin V (50–75 mg/kg/day in 3 or 4 doses);

•Alternative: oral clindamycin (40 mg/kg/day in 3 doses)


Management of CAP: Antibiotic therapyMycoplasma pneumoniaeParenteral therapy

•Preferred: intravenous azithromycin (10 mg/kg on days 1 and 2 of therapy; transition to oral therapy if possible);

•Alternatives: intravenous erythromycin lactobionate (20 mg/kg/day every 6 hours) or levofloxacin (16-20 mg/kg/day every 12 hours; maximum daily dose, 750 mg)


Management of CAP: Antibiotic therapyMycoplasma pneumoniaeOral therapy

•Preferred: azithromycin (10 mg/kg on day 1, followed by 5 mg/kg/day once daily on days 2–5);

•Alternatives: clarithromycin (15 mg/kg/day in 2 doses) or oral erythromycin (40 mg/kg/day in 4 doses);

•for children >7 years old, doxycycline (2–4 mg/kg/day in 2 doses;

•for adolescents with skeletal maturity, levofloxacin (500 mg once daily) or moxifloxacin (400 mg once daily)



Pneumonia caused by MRSA

CA-MRSA: Antibiotic susceptibility

•Unlike HA-MRSA, usually susceptible to antibiotics other than vancomycin

•Typically also susceptible to

•Clindamycin (!inducible resistance!)

•TMP/SMX

•Gentamicin

•Erythromycin

•Fluoroquinolones

Barton M et al.Can J Infect Dis Med Microbiol 2006; 17(Suppl C): 1B-24B

CA-MRSA risk factors

•Children less than 2 years old

•Minority populations:

•Native or Aboriginal

• African-American

•Athletes (mainly contact-sport participants)

•Injection drug users

•Men who have sex with men

•Military personnel

•Inmates of correctional facilities

•Veterinarians, pet owners and pig farmers

Barton M et al.Can J Infect Dis Med Microbiol 2006; 17(Suppl C): 1B-24B

MRSA pneumonia in children:When to suspect…

•For children hospitalized with severe CAP empiric therapy for MRSA is recommended (pending sputum and/or blood culture results):

• Those requiring an intensive care unit (ICU) admission,

• OR Necrotizing or cavitary infiltrates,

• OR Empyema

Lui C, et al. Clin Infect Dis. 2011;52:1-38

Management of CAP: Antibiotic therapyMRSA susceptible to clindamycinParenteral therapy

•Preferred: vancomycin (40–60 mg/kg/day every 6–8 hours or dosing to achieve an AUC/MIC ratio of >400) or clindamycin (40 mg/kg/day every 6–8 hours);

•Alternatives: linezolid (30 mg/kg/day every 8 hours for children ,12 years old and 20 mg/kg/day every 12 hours for children $12 years old)


Management of CAP: Antibiotic therapyMRSA susceptible to clindamycinOral therapy

•Preferred: oral clindamycin (30–40 mg/kg/day in 3 or 4 doses);

•Alternatives: oral linezolid (30 mg/kg/day in 3 doses for children >12 years and 20 mg/kg/day in 2 doses for children ≥12 years)


Management of CAP: Antibiotic therapyMRSA resistant to clindamycinParenteral therapy

•Preferred: vancomycin (40–60 mg/kg/day every 6-8 hours or dosing to achieve an AUC/MIC ratio of >400);

•Alternatives: linezolid (30 mg/kg/day every 8 hours for children <12 years old and 20 mg/kg/day every 12 hours for children ≥12 years old)


Management of CAP: Antibiotic therapyMRSA resistant to clindamycinOral therapy

•Preferred: oral linezolid (30 mg/kg/day in 3 doses for children <12 years and 20 mg/kg/day in 2 doses for children ≥12 years old);

•Alternatives: none; entire treatment course with parenteral therapy may be required


MRSA pneumonia in childrenVancomycin Dosing in Children

•Vancomycin 15 mg/kg/dose every 6 h (60 mg/kg/day) is recommended for serious or invasive disease (data are limited to guide vancomycin dosing in children).

• Trough concentrations of 15–20 mcg/mL should be considered in those with serious infections, such as bacteremia, infective endocarditis, osteomyelitis, meningitis, pneumonia, and severe SSTI (eg, necrotizing fasciitis)

• The efficacy and safety of this dose requires additional study


MRSA pneumonia in childrenAdjunctive therapy for MRSA

•Not routinely recommended: Protein synthesis inhibitors (eg, clindamycin and linezolid) and intravenous immunoglobulin (IVIG)

•Some experts may consider these agents in selected scenarios (eg, necrotizing pneumonia or severe sepsis)


Management of CAP: Antibiotic therapyfor other etiologic agents

The guideline offers specific therapy recommendations for pediatric CAP caused by

•MSSA…

•H. influenzae, typable or not

•Chlamydia & Chlamydophila


Empyema

Empyema: definition

•Empyema is inflammatory fluid and debris in the pleural space. It results from an untreated pleural-space infection that progresses from free-flowing pleural fluid to a complex collection in the pleural space.

Pathophysiology

•Exudative stage

•Fibrinolytic stage

•Organization stage

Epidemiology

•Increase in incidence since the mid-nineties (USA)

•Particularly among certain age groups

Gupta R. Crowley S. Thorax 2006; 61:179-180

Finlay C et al. Can Respir J 2008

Variables associated with parapneumonic effusions

•Pneumococcal serotype? NO

•Age ≥ 3 years (p<0,0001)*

•Varicella (p<0,0001)*

•Fever ≥ 7 days (p<0,0001)*

•Medication use:

• Ibuprofen (p<0,0001)*

• Ceftriaxone (p<0,0001)*

*: Multivariate regression analysis

Parapneumonic effusions managementSmall effusions

•Size of effusion: Small: <10 mm on lateral decubitus radiograph or opacifies less than one-fourth of hemithorax

•Bacteriology: Bacterial culture and Gram stain results unknown or negative

•Risk of poor outcome: Low

•Tube drainage: No; sampling of pleural fluid is not routinely required


Parapneumonic effusions managementModerate effusions

•Size of effusion: Moderate: >10 mm rim of fluid but opacifies less than half of the hemithorax

•Bacteriology: Bacterial culture and/or Gram stain results negative or positive (empyema)

•Risk of poor outcome: Low to moderate

•Tube drainage:

• No, if the patient has no respiratory compromise and the pleural fluid is not consistent with empyema;

• Yes, if the patient has respiratory compromise or if pleural fluid is consistent with empyema


Parapneumonic effusions managementLarge effusions

•Size of effusion: Large: opacifies more than half of the hemithorax

•Bacteriology: Bacterial culture and/or Gram stain results positive (empyema)

•Risk of poor outcome: High

•Tube drainage: Yes, in most cases


Parapneumonic effusions managementAntibiotic therapy

•In the case of culture-negative parapneumonic effusions, antibiotic selection should be based on the treatment recommendations for patients hospitalized with CAP

•The duration of antibiotic treatment depends on the adequacy of drainage and on the clinical response demonstrated for each patient. In most children, antibiotic treatment for 2–4 weeks is adequate


Merci!


François Boucher MD, FRCPC Community acquired pneumonia (CAP): Why is this still a problem?

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