From the Guidelines
A pneumonia workup typically includes clinical assessment, chest imaging, and laboratory tests, with empiric antibiotic therapy initiated promptly based on severity of illness and patient risk factors, as recommended by the most recent guidelines 1. The workup for pneumonia involves several key components:
- Clinical assessment: Evaluate symptoms (cough, fever, dyspnea) and perform physical examination (auscultation, vital signs) to determine the severity of illness and identify potential risk factors for complications.
- Chest imaging: Obtain a chest X-ray to confirm diagnosis and assess severity, with consideration of CT scan for complicated cases or when the diagnosis is uncertain.
- Laboratory tests:
- Complete blood count (CBC)
- Blood cultures
- Sputum culture and Gram stain
- Urinary antigen tests for Streptococcus pneumoniae and Legionella
- Procalcitonin levels (if available)
- Arterial blood gas analysis for severe cases
- Additional tests based on clinical suspicion:
- Influenza PCR during flu season
- HIV testing if risk factors present
- Pleural fluid analysis if effusion present Empiric antibiotic therapy should be initiated promptly, with the choice of antibiotic guided by the severity of illness and patient risk factors, such as the presence of comorbidities or previous antibiotic use 1. For outpatients, a macrolide, doxycycline, or fluoroquinolone with enhanced activity against S. pneumoniae is recommended, while for inpatients, a fluoroquinolone alone or an extended-spectrum cephalosporin (cefotaxime or ceftriaxone) plus a macrolide is preferred 1. Adjusting antibiotics based on culture results and clinical response is crucial, and consideration of severity scores (e.g., CURB-65) can guide admission decisions and help identify patients at high risk for complications 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Diagnosis of Pneumonia
The diagnosis of pneumonia is suggested by a history of cough, dyspnea, pleuritic pain, or acute functional or cognitive decline, with abnormal vital signs and lung examination findings 2. Diagnosis should be confirmed by chest radiography or ultrasonography.
Clinical Evaluation
Clinical evaluation includes history, physical examination, and chest radiograph, but all are unreliable when used alone, and misdiagnosis occurs in up to one-third of patients 3. Clinical gestalt demonstrates greater ability to diagnose pneumonia, and clinical scores such as Pneumonia Severity Index (PSI) and Confusion, blood Urea nitrogen, Respiratory rate, Blood pressure, age 65 score (CURB-65) may be helpful for disposition.
Laboratory Tests
- Blood cultures are of limited utility in nonsevere community-acquired pneumonia, but may be useful in severe community-acquired pneumonia or health care-associated pneumonia 4.
- White Blood Count (WBC) more than 20 000, very high C-reactive protein (C-RP ≥8mg/L), and Temperature more than 40°C, had a positive predictive value for a positive blood culture in children under five years of age with clinically severe pneumonia 5.
- Laboratory findings such as erythrocyte sedimentation rate, C-reactive protein levels, and white blood cell count may be useful in evaluating community-acquired pneumonia 6.
Imaging Studies
- Chest radiograph has a sensitivity of 46-77% and may be negative in patients presenting early in disease course and elderly patients 3.
- Ultrasound has shown utility in correctly identifying pneumonia 3.
- Chest X-ray is required for patients with unreliable follow-ups or moderate to high likelihood of morbidity if community-acquired pneumonia is not initially detected 6.
Risk Stratification
- Validated prediction scores for pneumonia severity can guide the decision between outpatient and inpatient therapy 2.
- Using procalcitonin as a biomarker for severe infection may further assist with risk stratification 2.
Treatment
- Most outpatients with community-acquired pneumonia do not require microbiologic testing of sputum or blood and can be treated empirically with a macrolide, doxycycline, or a respiratory fluoroquinolone 2.
- Patients requiring hospitalization should be treated with a fluoroquinolone or a combination of beta-lactam plus macrolide antibiotics 2.