EBM: Pneumonia

Current Definitions

• Pneumonia: A new lung infiltrate with symptoms concerning for an infectious etiology. Should be considered in all patients with a cough and fever, with a high index of suspicion in elderly who present with generalized weakness, confusion, or worsening medical conditions. Certain clinical features direct you towards the diagnosis of pneumonia, however no single finding is able to predict pneumonia. 
• CAP: Acute infection in patients not hospitalized of longterm care facility within the past 14 days
• HAP: Acute infection 48 hours after hospitalization
• VAP: Acute infection 48 hours after intubation
• HCAP: No longer considered a diagnosis

Blood Cultures

Utilization of blood cultures can assist the treatment of many patients, however not every patient requires blood cultures. Whenever drawn, you should obtain two sets of cultures (or 3 for endocarditis). A recent article found a number needed to treat was 250 for a change in treatment, however other studies have found blood cultures more useful.

Major Criteria:

• temperature > 39.5°C (103.0°F)
  
• indwelling vascular catheter
  
• clinical suspicion of endocarditis
  

Minor criteria

• temperature 38.3–39.4°C (101– 102.9°F)
  
• age > 65 years
  
• chills
  
• vomiting
  
• hypotension (systolic blood pressure < 90 mm Hg)
  
• neutrophil% > 80
  
• white blood cell count > 18 k
  
• bands > 5%
  
• platelets < 150 k
  
• creatinine > 2.0.
  

​www.sciencedirect.com/science/article/pii/S0736467908004447?via%3DihubA blood culture is indicated by the rule if at least one major criterion or two minor criteria are present.

Admission Criteria: CURB 65 and PSI/PORT

Patients with CURB 65 scores 0-1 can potentially be discharged, however consider the patient's physical exam, oxygen saturation, and immunosupressed status, as the CURB 65 score does not take these into account. Those with a CURB 65 score greater than 3 should be considered for an ICU admission. 

The PSI/PORT score can also be used but is more thorough, including nursing home status, liver and heart disease status, as well as ABG data. While the CURB 65 has better specificity for identifying severe disease, the PSI/PORT score is more sensitive at identifying low-risk patients for discharge.

Treatment

For CAP, guidelines recommend Azithromycin or Doxycycline as azythromycin has increasing rates of resistance. In outpatients with co-morbidities or risk for resistance, you should consider levofloxacin or moxifloxacin. Patients admitted for CAP should be treated with single agent fluoroquinolone or dual agent treatment with ceftriaxone and azithromycin. ICU admitted CAP patients require an anti-pneumococcal betalactam (Ceftriaxone) and either azithromycin or fluoroquinolone. Treatment duration is typically 5 days.