An Approach To Community Acquired Pneumonia

1. An Approach To Community Acquired Pneumonia Laura Miles, Pediatrics Resident Otto Vanderkooi, Infectious Disease Specialist

2. Based on the 2011 clinical practice guidelines from the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America

3. What it does cover: • Children and Infants over 3 months of age • Community acquired pneumonia • Otherwise healthy patients • Inpatients or outpatients

4. 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)

5. WHO definitions • For resource poor areas pneumonia defined as: • Cough or difficulty breathing + age adjusted tachypnea • Severe pneumonia • Cough or difficulty breathing + 1 of: • Lower chest indrawing • Nasal flaring • Grunting

6. WHO definitions • Very severe pneumonia • Cough 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

7. 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

8. 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

9. 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

10. 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

11. 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 bobbing • Statistically associated with tachypnea

12. 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

13. 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

14. Investigations

15. 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

16. 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

17. 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 recommended • No reliable and readily available testing

18. Investigations - CBC • Routine measurement of CBC not necessary for children managed as outpatients • Should be obtained for patients with more serious disease

19. 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

20. 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

21. 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

22. Antimicrobial Therapy

23. In a preschooler diagnosed with community acquired pneumonia and treated as an outpatient, how should you treat?

24. Antimicrobial Therapy • Not routinely needed in preschoolers diagnosed with CAP – most commonly viral pathogens • Amoxicillin first line therapy for outpatient treatment for • Fully immunized infants and preschool children with CAP believed to be bacterial • Fully immunized and previously well school aged children with mild to moderate CAP • Note: consider atypical coverage

25. Antimicrobial Therapy • Macrolides first line for atypical pathogens • Should perform laboratory testing • Influenza treatment • As soon as possible for patients with infection consistent with influenza related CAP • Do not delay treatment while waiting for testing

26. 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 immunized • High level of penicillin resistance • Life threatening infection, including empyema

27. Antimicrobial Therapy - Inpatients • Vancomycin • Not been shown to be more effective than 3rd generation Cephalosporin in treatment of S. Pneumo • Add if concern for Staph Aureus • Macrolide • Add if concern about atypical pneumonia – should perform diagnostic testing

29. ACH Guidelines: • Jan 2009 – Dec 2011 • 93% of Strep Pneumo cultured sensitive to Penicillin • 96% sensistive of Cefotaxime • Empiric Antibiotic Guidelines PICU: • Severe community acquired pneumonia • Ceftriaxone • Vancomycin • Clarithromycin PO or Azithromycin IV • Oseltamivir (seasonal)

31. Duration of Therapy • Treatment regimens of 10 days well studied • Shorter might be ok • MRSA may require longer treatment than S. pneumo

32. Parapneumonic Effusions

33. 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

34. Parapneumonic Effusions • What determines the need for drainage? • Size of the effusion • Small effusions can be effectively treated with antibiotics • Degree of respiratory distress

35. 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

36. What Needs Drainage? • Moderate effusion associated with respiratory distress • Large parapneumonic effusion • Empyema • Diagnostic purposes • ? Concern about malignancy

37. 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

38. 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 days • Persistence of respiratory distress after 2-3 days • Persistence of fever alone is not a sign of failure

39. 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

40. 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

45. What do you send the pleural fluid for?

46. 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

47. 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

48. 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

49. 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

50. Children unresponsive to treatment • Imaging • For 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