Community-Acquired Pneumonia Treatment Guidelines

Initial Assessment and Treatment

The American Thoracic Society recommends that community-acquired pneumonia should be treated with specific antibiotic regimens based on severity, with empiric therapy initiated promptly while in the emergency department for hospitalized patients 1, 2
Severity assessment should guide the decision for outpatient versus inpatient treatment, with tools like CURB-65 helping to identify patients who may be safely treated as outpatients 3, 4
For patients admitted through the emergency department, the first antibiotic dose should be administered while still in the ED to minimize time to treatment 1
Empiric antibiotic therapy should be initiated in adults with clinically suspected and radiographically confirmed CAP regardless of initial serum procalcitonin level 2

The British Thoracic Society recommends Amoxicillin at higher doses than previously recommended as the preferred agent for outpatient treatment of CAP 3, 5
A macrolide (erythromycin or clarithromycin) is recommended as an alternative choice and for patients with penicillin allergies 3, 5
For patients referred to hospital with suspected CAP, general practitioners should consider administering antibiotics immediately if the illness is considered life-threatening or if admission delays are expected (over 2 hours) 3

Combined oral therapy with amoxicillin and a macrolide (erythromycin or clarithromycin) is preferred for patients requiring hospital admission for clinical reasons 3, 5
Most non-severe inpatients can be adequately treated with oral antibiotics 3
A respiratory fluoroquinolone (levofloxacin) may provide a useful alternative for those intolerant of penicillins or macrolides 3, 2

Patients with severe pneumonia should be treated immediately after diagnosis with parenteral antibiotics 3
The Infectious Diseases Society of America recommends a standard regimen of β-lactam plus macrolide or β-lactam plus respiratory fluoroquinolone 2
For Pseudomonas infection, use an antipneumococcal, antipseudomonal β-lactam (piperacillin-tazobactam, cefepime, imipenem, or meropenem) plus either ciprofloxacin or levofloxacin (750-mg dose) 1, 6
For community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection, add vancomycin or linezolid 1, 7

Patients with CAP should be treated for a minimum of 5 days 1, 7
Patients should be afebrile for 48–72 hours and have no more than 1 CAP-associated sign of clinical instability before discontinuation of therapy 1
A longer duration of therapy may be needed if initial therapy was not active against the identified pathogen or if complicated by extrapulmonary infection 1, 7

Patients should be switched from intravenous to oral therapy when they are hemodynamically stable and improving clinically 8
Patients should be able to ingest medications and have a normally functioning gastrointestinal tract 9, 1, 8

Once the etiology of CAP has been identified using reliable microbiological methods, antimicrobial therapy should be directed at that specific pathogen 1, 8
Early treatment (within 48 hours of symptom onset) is recommended 1

For patients with hypoxemia or respiratory distress, a cautious trial of noninvasive ventilation is recommended unless immediate intubation is required due to severe hypoxemia 1, 8
Low-tidal-volume ventilation (6 cm³/kg of ideal body weight) should be used for patients undergoing ventilation who have diffuse bilateral pneumonia or acute respiratory distress syndrome 1, 8
Patients with CAP who have persistent septic shock despite adequate fluid resuscitation should be considered for treatment with drotrecogin alfa activated within 24 hours of admission 1, 7

Clinical review should be arranged for all patients at around 6 weeks, either with their general practitioner or in a hospital clinic 3, 4
A chest radiograph should be arranged at follow-up for patients with persistent symptoms or physical signs, or who are at higher risk of underlying malignancy (especially smokers and those over 50 years) 3, 4