community acquired pneumonia (CAP) in adults

see also:

• pneumonia
• pneumococcus
• Legionella (Legionaire's disease)
• psittacosis
• RCH guideline - paediatric pneumonia
• AFTB lectures - community acquired pneumonia (CAP)

• CAP means pneumonia acquired in the community and NOT following a period of recent hospitalisation where there would be a much higher risk of antibiotic resistant or different organisms causing the pneumonia
• for a clinical diagnosis of CAP, one generally would like to see:
  • typical clinical picture of cough, fever, SOB, and purulent sputum, combined with
  • CXR infiltrate consistent with pneumonia
• patients with bilateral interstitial changes may still be pneumococcal but other causes should be considered such as:
  • atypical pneumoniae - eg. Legionella (Legionaire's disease), mycoplasma, psittacosis, etc
  • viral - eg. influenza, varicella
  • Pneumocystis (carinii) jirovecii pneumonia (PCP)

• supplemental oxygen Rx if SaO2 < 92%
• FBE, U&E, glucose
• consider iv access and iv fluids if confused, dehydrated or hypotensive, or likely to need admission
• CXR
• if patient likely to be admitted, send the following cultures:
  • sputum m/c/s and consider AFB's if at risk of tuberculosis (TB)
  • blood cultures
  • urine for Legionella and Pneumococcal antigens
  • throat swab for respiratory viral PCR if influenza season
• aim to start antibiotic Rx ASAP and within 4 hours of presentation

• age < 50
• heart rate < 125/min
• temp > 35deg C and < 40 deg C
• no comordities such as cancer, congestive cardiac failure, renal disease or CVD
• CORB score = 0
• SMART-COP score < 3

• amoxycillin o 1g tds for 7 days
• +/- doxycycline o 200mg stat then 100mg bd for 5 days

• not mild CAP as above, and,
• CORB score < 2
• SMART-COP < 5

• benzyl penicillin iv 1.2g 6hrly, plus,
• doxycycline o 200mg stat then 100mg bd for 7 days
• plus, if Gram negatives suspected or found in cultures, add gentamicin iv 5mg/kg stat dose
• continue iv benzyl penicillin until significant improvement then switch to amoxycillin o 1g tds for 7 days

• discuss with Infectious Diseases consultant
• examples of regimes in 2012 as per ETG:
  • moxifloxacin 400mg iv daily, AND
  • azithromycin 500mg iv daily

• substitute benzyl penicillin with ceftriaxone iv 1g daily until significant improvement, then cefuroxime o 500mg bd for 7 days.

• not mild or moderate CAP as above, and,
• CORB score > 1
• SMART-COP > 4

• ceftriaxone iv 1g daily, plus,
• azithromycin iv 500mg daily
• use culture results to determine appropriate antibiotic for oral Rx
• consider other risk factors such as immunosuppression, HIV / AIDS, etc.

• allergic to above
• a returned traveler (including from Northern Territory)
• risk factors for Staph. aureus infection

• score 1 point for each of:
  • Confusional state (acute)
  • Oxygen saturation ⇐ 90% in room air
  • Respiratory rate >= 30/min
  • BP: systolic < 90mmHg or diastolic BP ⇐ 60mmHg
• a score of > 1 has sensitivity 81%, specificity 68%, PPV 18%, NPV 98% and area under ROC 0.74 for requiring intensive respiratory or vasopressor support.

• all items get 1 point EXCEPT BP, Oxygen and pH parameters which get 2 points, giving a maximum score of 11
• different calculators depending on age

• scores 0-2 = low risk
• scores 3-4 = moderate risk (1 in 8 chance)
• scores 5-6 = high risk (1 in 3 chance)
• scores 7 or more = very high risk (2 in 3 chance)
• a score of 3 or more gives sensitivity 92%, specificity 62%, PPV 22%, NPV 99%, area under ROC 0.84

• Systolic BP < 90mmHg
• Multilobar CXR involvement
• Albumin < 35g/L
• Respiratory rate >= 25/min
• Tachycardia >= 125/min
• Confusion (acute)
• Oxygen low (PaO2 < 70mmHg, or SaO2 ⇐ 93%, or PaO2/FiO2 < 333)
• pH < 7.35

• Systolic BP < 90mmHg
• Multilobar CXR involvement
• Albumin < 35g/L
• Respiratory rate >= 30/min
• Tachycardia >= 125/min
• Confusion (acute)
• Oxygen low (PaO2 < 60mmHg, or SaO2 ⇐ 90%, or PaO2/FiO2 < 250)
• pH < 7.35

• score 1 point for each of:
  • Confusion
  • Urea > 7mmol/L
  • Respiratory rate >= 30/min
  • BP: systolic < 90mmHg or diastolic BP ⇐ 60mmHg
  • 65: Age > 65 years
• a score of > 1 suggests inpatient Mx is needed
• a score of > 2 suggests HDU/ICU Mx may be needed - particularly if score 4 or 5

• a more complicated tool, but better validated.

• Adult community acquired pneumonia mortality risk scoring tool