Findings and Management of Pneumonia
The diagnosis of pneumonia requires clinical findings (fever, cough, dyspnea) combined with radiographic confirmation, followed by empiric antibiotic therapy based on severity and likely pathogens, with hospitalization decisions guided by validated severity scores. 1
Diagnostic Findings
Clinical Presentation
- Patients with pneumonia typically present with respiratory symptoms including new or increased cough, sputum production, and dyspnea, often accompanied by fever (>38°C) 1, 2
- Systemic symptoms may include confusion, particularly in elderly patients who may present with nonrespiratory symptoms such as altered mental status or worsening of underlying chronic conditions 1
- Physical examination findings include abnormal breath sounds and crackles on auscultation, though the absence of any vital sign abnormalities or chest auscultation abnormalities substantially reduces the likelihood of pneumonia 1, 3
- Tachypnea (elevated respiratory rate) is a particularly important vital sign to assess as it correlates with disease severity 1
Radiographic Findings
- Standard posteroanterior (PA) and lateral chest radiographs are essential for confirming the diagnosis of pneumonia 1
- Radiographic findings include air space density, infiltrates, which may be lobar, multilobar, or diffuse 2
- Multilobar involvement on chest radiograph is associated with increased severity and poorer prognosis 1, 4
- Pleural effusions may be present and require evaluation, particularly if the patient is not responding to therapy 1
- Radiographic clearing typically lags behind clinical improvement, with only 60% of otherwise healthy patients under 50 years showing complete resolution at 4 weeks, and only 25% of older patients or those with comorbidities 1
Laboratory Assessment
- Complete blood count with differential (leukocytosis or leukopenia may be present) 1
- Blood chemistry tests including renal and liver function, electrolytes, and glucose should be obtained for hospitalized patients 1
- Blood cultures (two sets) should be collected prior to antibiotic administration in hospitalized patients 1
- Sputum Gram stain and culture should be obtained if drug-resistant bacteria or organisms not covered by empiric therapy are suspected 1
- Oxygen saturation assessment via pulse oximetry for all patients, with arterial blood gas analysis for those with severe illness or chronic lung disease 1
Severity Assessment and Site-of-Care Decisions
Severity Assessment Tools
- Pneumonia Severity Index (PSI) stratifies patients into five risk classes based on age, comorbidities, physical examination findings, and laboratory results 1, 5
- CURB-65 score (Confusion, blood Urea nitrogen, Respiratory rate, Blood pressure, age >65) provides a simpler alternative for risk stratification 5
- Severe pneumonia is characterized by one or more of: acute respiratory failure, hemodynamic compromise, sepsis/septic shock, or multilobar radiographic infiltrates 4
Hospitalization Criteria
- Consider hospitalization for patients with:
- Abnormal vital signs (respiratory rate, systolic and diastolic blood pressure) 1
- Signs of dehydration or altered mental status 1
- Multilobar pneumonia or pleural effusion on radiograph 1
- Underlying chronic heart or lung disease 1
- Age ≥65 years or significant comorbidities 1
- Inability to maintain oral intake or inadequate home support 1
ICU Admission Criteria
- Consider ICU admission for patients with:
Management Approach
Antibiotic Therapy
- Outpatients without comorbidities: macrolide (e.g., azithromycin), doxycycline, or respiratory fluoroquinolone 1
- Hospitalized non-ICU patients: intravenous β-lactam (ceftriaxone, cefotaxime) plus a macrolide (azithromycin), or a respiratory fluoroquinolone alone 1
- ICU patients without Pseudomonas risk: intravenous β-lactam (cefotaxime, ceftriaxone) plus either a macrolide or fluoroquinolone 1
- ICU patients with Pseudomonas risk: antipseudomonal β-lactam (cefepime, imipenem, meropenem, piperacillin/tazobactam) plus either an antipseudomonal quinolone or an aminoglycoside plus a macrolide 1
- First dose of antibiotics should be administered within 8 hours of hospital arrival 1
Duration and Response Assessment
- Most patients show clinical improvement within 3-5 days of appropriate therapy 1
- Switch from intravenous to oral therapy when the patient has:
- Improved cough and dyspnea
- Temperature <100°F on two occasions 8 hours apart
- Decreasing white blood cell count
- Functioning gastrointestinal tract with adequate oral intake 1
- Total duration of therapy is typically 5-7 days for uncomplicated cases 1, 2
- Radiographic improvement typically lags behind clinical improvement 1
Management of Non-Responding Patients
- For patients not responding after 48-72 hours:
- Do not change antibiotics within first 72 hours unless marked clinical deterioration 1
- Reassess with repeat chest imaging to evaluate for complications (empyema, lung abscess) 1
- Consider bronchoscopy or other invasive diagnostic procedures if no improvement 1
- Evaluate for resistant pathogens, unusual organisms, or non-infectious mimics of pneumonia 1
- Consider complications such as metastatic infection (endocarditis, meningitis) 1
Complications to Monitor
- Parapneumonic effusion or empyema requiring drainage 1
- Lung abscess or necrotizing pneumonia 1
- Metastatic infections (meningitis, endocarditis, septic arthritis) in up to 10% of bacteremic pneumococcal pneumonia 1
- Acute respiratory distress syndrome (ARDS) in severe cases 1
- Clostridium difficile-associated diarrhea as a complication of antibiotic therapy 6