Definitions

1. Community-acquired pneumonia (CAP): acquired outside a hospital or long-term care facility.
2. Hospital-acquired pneumonia (HAP): pneumonia developing >48 hours after admission.
3. Ventilator-associated pneumonia (VAP): pneumonia developing after >48 hours of mechanical ventilation.

Evaluation

• Symptoms: fever, chills, productive cough, increased sputum, SOB, pleuritic chest pain. Presenting symptoms may be subtle (e.g., weakness, malaise, AMS), especially in elderly patients.
• Major findings: purulent sputum, infiltrate on CXR, leukocytosis.
• Other studies:
  • Blood culture before antibiotic administration.
  • ABG when patient is severely dyspneic or tachypneic.
  • Consider testing for Legionella (culture and urinary assay), Mycoplasma (cold agglutinins), S. pneumoniae (urine antigen), Chlamydia (acute and convalescent serology), or respiratory viral panel if clinical course is atypical or enigmatic. Suspect Legionella if GI symptoms and hyponatremia are present.
  • Sputum gram stain and culture: while controversial, it is helpful if performed before antibiotics; an adequate sample has >25 PMNs and <10 epithelial cells.
  • Consider HIV testing if never previously tested or if risk factors for HIV.
  • In HIV-positive patients, consider diagnostic workup for opportunistic pathogens (PCP, TB, fungi).
  • Consider COVID testing given radiographic overlap with atypical pneumonias.
• Decision to hospitalize can be further guided by clinical prediction tools such as the Pneumonia Severity Index and CURB-65 scores.
• Healthcare-associated pneumonia (HCAP): the concept of healthcare-associated pneumonia (HCAP), i.e. pneumonia that is acquired outside the hospital in patients with healthcare-associated risk factors, is no longer included in the guidelines for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). Patients admitted for pneumonia with a history of contact with the healthcare system (e.g. past hospital admission within 90 days, dialysis) are treated for CAP.

Management

• Antibiotic regimen depends on severity of illness (ICU: severe, ward: non-severe) and potential for resistant or opportunistic pathogens.
• Consult your hospital’s antibiogram and antibiotic guidelines (https://idmp.ucsf.edu/guidelines-empiric-antimicrobial-therapy). Adjust for renal/hepatic insufficiency as needed. First dose of antibiotics should be given within 1-3 hours of presentation.
• Pseudomonas risk factors: respiratory isolation or known colonization with pseudomonas, recent IV antibiotics with hospitalization within the past 90 days, structural lung disease (e.g., bronchiectasis), immunodeficiency [e.g. corticosteroid therapy (>10 mg of prednisone or equivalent per day), HIV, solid organ or hematopoietic transplant recipients].
• Community-acquired MRSA (CA-MRSA) risk factors: respiratory isolation or known colonization (including MRSA nares swab) with MRSA, recent IV antibiotics with hospitalization within the past 90 days, immunodeficiency [e.g. corticosteroid therapy (>10 mg of prednisone or equivalent per day), HIV, solid organ or hematopoietic transplant recipients], injection drug use, crowded living conditions, MSM, recent influenza-like illness, typical presentation as multifocal, necrotizing pneumonia.
• High risk of multi-drug resistant (MDR) pathogens: respiratory isolation or known colonization, recent IV antibiotics with hospitalization within the past 90 days, late-onset HAP or VAP (developing >5 days after hospitalization).
• Adjunctive glucocorticoids: consider in those with severe PNA (i.e. septic shock 2/2 PNA). Otherwise, glucocorticoids are not a mainstay of PNA therapy, as data from a meta-analyses among hospitalized patients with CAP has not shown benefit.

• For aspiration pneumonia, see Pulmonary: Aspiration Pneumonia/Pneumonitis.
• For ventilator-associated pneumonia, see Critical Care: Ventilator-Associated Pneumonia.
• For updated empiric antibiotic recommendations for UCSF, visit idmp.ucsf.edu.

Discharge Planning

1. Patients should be afebrile with stable vital signs (T <37.8°C, RR <24, HR <100, SBP >90). They should also be able to tolerate oral feeding/medications, maintain hydration, and have an oxygen saturation ≥90% on room air or at previous oxygen requirement.
2. There is no need for a 24-hour observation period on oral antibiotics prior to discharge.
3. Discharge antibiotics should cover both typical and atypical organisms (e.g., doxycycline).
4. Evaluate all patients for pneumococcal and influenza vaccines, and counsel on smoking cessation.
5. Duration of antibiotics is typically 5-7 days. Patient should be afebrile for at least 48 hours before discontinuation of therapy.
6. Cough may persist for 2-6 weeks; full recovery can take up to 6 months.
7. Only consider repeat CXR 2-3 months later to look for malignancy if concern for post-obstructive PNA.

Halm EA, Teirstein AS. Clinical practice. Management of community-acquired pneumonia. N Engl J Med 2002;347:2039-2045.

Hoare A, Lim WS. Pneumonia: update on diagnosis and management. BMJ 2006;332:1077-1079.

Joshua P. Metlay, Grant W. Waterer, Ann C. Long, Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America. American Journal of Respiratory and Critical Care Medicine. 2019, e45-e67.

Kalil A., Metersky, M, Klompas M. Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clinical Infectious Diseases, 63, 5, 2016, e61–e111.

Schuetz P, Muller B, Christ-Crain M, et al. Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections. Cochrane Database Syst Rev 2012;9:CD007498.