Pneumonia - Community-Acquired Theo dõi

Theo dõi

Low-risk Community-acquired Pneumonia  

Most patients respond to treatment within 24-72 hours. The indicators of response to therapy include a decline of fever within 72 hours, return of temperature to normal within 5 days, and resolution of respiratory signs.  

Moderate-risk and High-risk Community-acquired Pneumonia  

Streamlining initial empiric broad-spectrum parenteral therapy to a single narrow-spectrum parenteral or oral agent based on available laboratory data is recommended as early as 24-72 hours following initiation of empirical treatment. The indications for streamlining antibiotic therapy include the following: 

• Less cough and normalization of respiratory rate
• Afebrile for >24 hours
• Blood cultures are negative or etiology is not a high-risk (virulent/resistant) pathogen
• No unstable comorbid condition or life-threatening complication (eg MI, CHF, complete heart block, new atrial fibrillation, supraventricular tachycardia)
• No obvious reason for continued hospitalization (eg hypotension, acute mental changes, BUN: creatinine ratio of >10:1, hypoxemia, metabolic acidosis, etc.)
• Able to initiate and maintain oral intake

Switching therapy to an oral agent will allow discharge from the hospital as early as the fourth day of hospitalization and will lead to cost savings. Blood and sputum cultures should be obtained in patients given empiric therapy for MRSA or Pseudomonas aeruginosa.  Agents should be de-escalated after two days if cultures are negative and with clinical improvement. Inpatient observation while receiving oral therapy is not necessary.

Poor Response to Treatment  

Major causes of antibiotic failure include a mismatch between the causative organism and agent used, a causative agent not covered by usual empirical treatment, and the presence of nosocomial superinfection pneumonia or complications (eg empyema).  Patients with poor response to treatment may do a follow-up chest X-ray or computed tomography (CT) scan and be reassessed for possible resistance to the antibiotics being given. In these patients, consideration should be given to other pathogens (eg Mycobacterium tuberculosis, viruses, parasites, or fungi) and other conditions (eg pneumothorax, cavitation and extension to previously uninvolved lobes, pulmonary edema, and acute respiratory distress syndrome [ARDS]).  Treatment should be revised based on the causative agents and sensitivity test results (pathogen-specific antimicrobial therapy).

• Streptococcus pneumoniae: Penicillin G, Amoxicillin
  • Alternative: Macrolide, second-third generation cephalosporin
• Haemophilus influenzae: Amoxicillin, second-third generation cephalosporin, Amoxicillin-clavulanate
  • Alternative: Fluoroquinolone
• Mycoplasma pneumoniae or Chlamydophila pneumoniae: Macrolide, tetracycline
  • Alternative: Fluoroquinolone
• Legionella sp: Fluoroquinolone, Macrolide (Clarithromycin, Azithromycin)
• Chlamydophila psittaci, Coxiella burnetti: Tetracycline
  • Alternative: Macrolide
• Pseudomonas aeruginosa: Antipseudomonal beta-lactam plus (Ciprofloxacin or Levofloxacin or aminoglycoside)
• Acinetobacter sp: Carbapenem
• Staphylococcus aureus: Antistaphylococcal penicillin if methicillin-susceptible; Vancomycin or Linezolid if methicillin-resistant
• Enterobacteriaceae: Extended-spectrum beta-lactamase producer (third generation cephalosporin, carbapenem)

Treatment Failure  

Treatment failure is generally defined as a lack of response or worsening of clinical status. Patients may show hemodynamic instability, impairment of respiratory function, the need for mechanical ventilation, radiographic progression, and appearance of new metastatic infectious foci.  

The management of treatment failure begins with the reassessment of the patient for possible resistance to antibiotics being given and considering the presence of other pathogens (eg Mycobacterium tuberculosis, viruses, parasites, or fungi). Repeat measurement of C-reactive protein (CRP) and repeat chest X-ray may be done if without any clinical improvement 3 days after initiation of therapy. In addition to microbiological diagnostic procedures, chest CT scan, thoracentesis, bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial biopsies, and chest X-ray should be considered. Follow-up chest X-ray should be done to identify pneumothorax, cavitation, and extension to previously uninvolved lobes, pulmonary edema, and acute respiratory distress syndrome. Reassess treatment accordingly thereafter.  

Criteria for Discharge  

Prior to discharge, it is important to review the patient’s status within 24 hours of planned discharge. During the assessment, patients should fulfill the following criteria:

• Temperature of 36-37.5°C
• Pulse rate of <100 beats/minute
• Respiratory rate of 16-24 breaths/minute
• Systolic blood pressure of >90 mmHg
• Blood oxygen saturation of >90%
• Ability to eat and take oral antibiotics
• Absence of active clinical or psychosocial problems requiring hospital stay