an approach to community acquired pneumonia laura miles, pediatrics resident otto vanderkooi,...
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An Approach To Community Acquired
PneumoniaLaura Miles, Pediatrics Resident
Otto Vanderkooi, Infectious Disease Specialist
Based on the 2011 clinical practice guidelines from the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America
What it does cover:
Children and Infants over 3 months of age
Community acquired pneumonia
Otherwise healthy patients
Inpatients or outpatients
What it does not cover:
Infants under 3 months of age
Immunocompromised patients
Children with home ventilation devices
Children with underlying chronic disease
Children with underlying lung disease (eg cystic fibrosis)
WHO definitions
For resource poor areas pneumonia defined as:Cough or difficulty breathing + age adjusted
tachypnea
Severe pneumoniaCough or difficulty breathing + 1 of:
Lower chest indrawing Nasal flaring Grunting
WHO definitions
Very severe pneumoniaCough or difficulty breathing + 1 of:
Cyanosis Severe respiratory distress Inability to drink or severe vomiting Lethargy/unconsciousness/convulsions
These classifications not well validated in resource rich areas
Signs of Respiratory Distress Tachpnea
0-2 mo >60 2-12 mo >50 1-5 yrs > 40 > 5 yrs >20
Dyspnea
Retractions
Grunting
Nasal Flaring
Apnea
Altered Mental Status
Pulse oximetry measurement < 90% in room air
Definitions
Simple pneumonia Bronchopneumonia
Primarily involving airways and surrounding interstitium Lobar pneumonia involving a single lobe
Complicated pneumonia Parapneumonic effusion Multilobar disease Abscess Cavities Necrotizing pneumonia Empyema Bronchopulmonary fistula Pneumothorax
What bugs are we treating?
Viral (RSV, adenoviruses, bocavirus, influenza viruses, coronavirus)
Strep pneumoniae
Group A Streptococcus
Staph MSSA MRSA
Haemophilus Influenzae Typeable Non-typeable
Mycoplasma Pneumonia
Chlamydia Trachomatis or Chlamydophilia Pneumonia
Hospitalization?
Clinical severity of illness – ‘toxic appearance’
Hypoxemia (<90%)
Infants < 3-6 months of age
Suspected bug with increased virulence (eg MRSA)
Concern about home environment
Unable to take adequate PO
Many adult scoring systems – not validated in pediatrics
Predictors of outcome
Hypoxemia (<90%)
Tachypnea In study using WHO defined tachypnea
20% of tachypneic children had pneumonia vs 12% of children who weren’t tachypneic
Retractions and grunting
Head bobbingStatistically associated with tachypnea
Guidelines for ICU Admission
Impending respiratory failure
O2 sat < 92 % on greater than 50% FiO2
Altered mental status
Need for blood pressure support
Severity of illness scores don’t provide enough information alone to decide – use the overall clinical pictures
Guidelines for ICU admission
Underlying pathogen plays a significant role in severity of illness In patients with invasive pneumococcal infection
with with concurrent viral infection More likely to need ICU admission Prolonged ICU stay
2 retrospective case studies, MRSA pneumonia High incidence of necrotizing pneumonia Need for ICU care Higher mortality
Investigations
Investigations – Blood Cultures
Blood cultures should not be obtained in fully immunized patients managed as outpatients
Should be obtained: Patients failing initial therapy Mod-Severe pneumonia requiring admission
In improving patients, positive culture should not preclude discharge
Repeat blood cultures in improving patients not necessary to document resolution of pneumococcal bacteremia
Repeat cultures should be obtained in children with documented Staph Aureus
Investigations – other tests
Sputum samples should be obtained in hospitalized patients who can produce sputum
Urinary antigen tests not recommended for diagnosis of pneumococcal pneumonia in pediatric patients
Test for respiratory viruses should be sent on all admitted patients
No need for antibacterial therapy in patients with positive viral test and no evidence of bacterial co-infection on clinical assessment or laboratory or imaging investigations
Investigations – atypical bacteria
If signs and symptoms suspicious for M. pneumoniae – should be tested to help guide antibiotic selection
Diagnostic testing for C. pneumoniae not recommendedNo reliable and readily available testing
Investigations - CBC
Routine measurement of CBC not necessary for children managed as outpatients
Should be obtained for patients with more serious disease
Investigations – Acute phase reactants
ESR,CRP should not be used as sole determinant of bacterial vs viral pneumonia
Don’t routinely measure in fully immunized children managed as outpatients
In patients with more severe disease – may be useful to assess response to therapy in conjunction with clinical assessment
Investigations - CXR
Not routinely needed in patients treated with outpatients
Should be performed in all patients with hypoxemia or significant respiratory distress
Should be performed in patients with failed antibiotic therapy
Repeat CXR not required in patients who recover well
Routine daily x-rays not required for patients who remain stable post VATS or chest tube insertion
Investigations - CXR
f/u X ray should be performed 4-6 weeks later patients with recurrent pneumonia in the same lobe lobar collapse on initial x-ray or any suspicion for anatomic anomaly or suspicion for foreign body aspiration
Antimicrobial Therapy
In a preschooler diagnosed with community acquired pneumonia and treated as an outpatient, how should you treat?
Antimicrobial Therapy
Not routinely needed in preschoolers diagnosed with CAP – most commonly viral pathogens
Amoxicillin first line therapy for outpatient treatment forFully immunized infants and preschool children with
CAP believed to be bacterialFully immunized and previously well school aged
children with mild to moderate CAP Note: consider atypical coverage
Antimicrobial Therapy
Macrolides first line for atypical pathogensShould perform laboratory testing
Influenza treatmentAs soon as possible for patients with infection
consistent with influenza related CAPDo not delay treatment while waiting for testing
Antimicrobial Therapy - Inpatients
Ampicillin or Penicillin G first line in areas without high S. Pneumo resistance rates
Third generation Cephalosporin (Ceftriaxone, Ceftoaxime) if:Not fully immunizedHigh level of penicillin resistanceLife threatening infection, including empyema
Antimicrobial Therapy - Inpatients
VancomycinNot been shown to be more effective than 3rd
generation Cephalosporin in treatment of S. PneumoAdd if concern for Staph Aureus
MacrolideAdd if concern about atypical pneumonia – should
perform diagnostic testing
ACH Guidelines:
Jan 2009 – Dec 2011 93% of Strep Pneumo cultured sensitive to Penicillin96% sensistive of Cefotaxime
Empiric Antibiotic Guidelines PICU:Severe community acquired pneumonia
Ceftriaxone Vancomycin Clarithromycin PO or Azithromycin IV Oseltamivir (seasonal)
Duration of Therapy
Treatment regimens of 10 days well studiedShorter might be ok
MRSA may require longer treatment than S. pneumo
Parapneumonic Effusions
Parapneumonic Effusions
Collection of fluid in the pleural space with associated pneumonia
Occur in 2-12% of patients with community acquired pneumonia
May occur in up to 20% of patients with M. pneumonia
Seen in ~10% of viral pneumonias
Parapneumonic Effusions
What determines the need for drainage?Size of the effusion
Small effusions can be effectively treated with antibiotics
Degree of respiratory distress
Effusion Size Criteria
Mostly subjective
Small effusion< 10 mm rim of fluid on lateral decubitus< ¼ of hemithorax opacified on upright CXR
Large effusion> 50% of hemithorax is opacified
Moderate effusion In between
What Needs Drainage?
Moderate effusion associated with respiratory distress
Large parapneumonic effusion
Empyema
Diagnostic purposes ? Concern about malignancy
How to Drain?
Both chest thoracostomy tubes (with the addition of fibrinolytic agents ie TPA) and VATS have been shown to be effective
Both associated with decreased morbidity compared to chest tube alone
In non-loculated effusions – chest tube alone may be a reasonable first option
Next Steps
Consider stepping up to VATS or open decortication post chest tube insertion (+/- fibrinolytic therapy) if:Persistence of moderate or large effusion after 2-3
daysPersistence of respiratory distress after 2-3 daysPersistence of fever alone is not a sign of failure
Next Steps
Should perform CT chest to assess adequacy of drainage, assess for loculation or necrotizing parenchymal disease
Open thoracotomy with decortication is sometimes necessary post VATS but associated with higher morbidity
Chest Tube Removal?
Absence of intrathoracic air leak
Chest tube drainage less than 1 ml/kg/24h (but usually calculated over 12 hours)
Usually can remove within 48-72 hours post insertion
What do you send the pleural fluid for?
Pleural Fluid Studies
Gram stain and culture
Antigen testing or Nucleic Acid Amplification testing by PCR
WBC and differential Helps to differentiate bacterial from fungal or
mycobacterial infection or malignancy
AFB
Analysis of pH, glucose, protein and LD Not likely to change management Not recommended
Antibiotic Therapy
If you have positive blood or pleural fluid cultures – tailor antibiotics appropriately
If blood and pleural fluid are culture negative – base antibiotic choice off of guidelines for CAP in hospitalized children
Treatment duration depends on adequacy of drainage and clinical response to therapy – usually 2-4 weeks
Some experts recommend 10 days post fever resolution
Antibiotic Therapy
S. Pneumoniae most commonly isolated pathogen in most studies
Staph Aureus – important cause of empyema but less common cause of uncomplicated CAP
More likely to get a positive blood culture in empyema caused by Staph Aureus than in S. Pneumoniae
Children Unresponsive to Treatment
Considered nonresponsive after 48-72 hours of initial therapy or with significant worsening any time during therapy
Estimated at between 5 and 15% of hospitalized patients
Children unresponsive to treatment
ImagingFor outpatients start with CXR If pleural effusion is suspected
Lateral decubitus x-ray Chest ultrasound
If chest mass, necrotizing pneumonia or chest abscess suspected CT chest
Children Unresponsive to Treatment
Consider drainage/VATS for effusions
Try to get a bugObtain pleural fluid samples in children who can
expectorateSend pleural fluid from drainage sampleTracheal aspirate or BAL for intubated patients
Consider expanding antibiotic coverage
Reassess for possible viral infection, mycobacterial or fungal infection
Children Unresponsive to Treatment
In children with underlying influenza infection who do not respond to oseltamivir – consider testing for oseltamivir resistance and use of alternate antiviral therapies (eg Zanamivir)
In children with initially confirmed viral CAP – consider secondary bacterial infection
Consider testing for atypical organisms and empiric coverage with a macrolide, tetracycline or fluoroquinolone
Pulmonary Abscess or Necrotizing Pneumonia in Nonresponding Patients
CT chest with contrast to confirm
Try to avoid surgical intervention – most will respond with antibiotics alone
For peripheral abscess with no airway communicationConsider CT guided drainage or catheter placement
Discharge Criteria
Decreasing fever
No supplemental oxygen (pulse oximetry > 90%)
Adequate oral intake
Free of intrathoracic leak for at least 12-24 hours post chest tube removal
Tolerating oral therapy
May want to observe patients with no surgical intervention longer for reaccumulation
Step down to Oral vs HPTP
When possible, conversion to oral step down is preferred to HPTP
No well defined criteria to identify patients requiring prolonged parenteral therapy
Required in patients requiring a high antibiotic concentration to achieve adequate exposure to effective tissuesParapneumonic effusionExtensive parenchymal diseaseLung abscess
Oral vs HPTP
No randomized control trials to demonstrate effectiveness of parenteral over oral therapy
Risk of catheter related complications
Reserve home parenteral therapy for patientsUnable to tolerate oral therapyWith pathogens that do not have appropriate oral
therapy
Prevention
Immunize,
immunize,
immunize!
Prevention
Immunize children against S. pneumoniae, H. influenzae type B and pertussis
Flu vaccine for all children > 6 months of ageDecreased incidence of pneumococcal CAP after
influenza infection
Parents and caregivers of infants < 6 months should be immunized against influenza and pertussis to avoid spreading disease
High risk infants should be vaccinated with RSV specific monoclonal antibody (Synagis)
Thanks!
Questions?
References
John S. Bradley et al. The Management of Community Acquired Pneumonia in Infants and Children Over 3 Months of Age: Clinical Practice Guidelines by the Pediatric Infectious Disease Society and the Infectious Diseases Society of America IDSA Guidelines. Clinical Infectious Diseases. August 2011.