Initial Treatment Approach for Respiratory Infections
For respiratory infections, the initial treatment approach should be based on distinguishing between upper and lower respiratory tract infections, with empiric antibiotic therapy reserved for bacterial infections while most viral infections can be managed with supportive care. 1
Diagnostic Assessment
- Initial clinical assessment is essential to distinguish between upper respiratory tract infections (URTI) occurring above the vocal cords with normal pulmonary auscultation, and lower respiratory tract infections (LRTI) with cough and/or febrile polypnea 1
- Diagnosis of LRTI is typically based on the symptomatic triad of fever, cough, and respiratory distress of varying intensity 1
- For pneumonia, assessment using the CRB65 score (Confusion, Respiratory rate, Blood pressure, age ≥65) should be performed to inform decisions about the appropriate care pathway 1
- Point-of-care biomarker and microbiological tests alone should not determine care at first presentation 1
Treatment Algorithm Based on Diagnosis
Upper Respiratory Tract Infections (URTI)
- Most URTIs are viral in origin and self-limiting, requiring only supportive care 1, 2
- Over-the-counter (OTC) medications may provide symptomatic relief for fever, muscle aches, cough, runny nose, and nasal congestion 2
- Antibiotic therapy is generally not indicated for viral URTIs 3
Lower Respiratory Tract Infections (LRTI)
1. Acute Bronchitis
- Usually viral in origin and does not require antibiotic therapy unless there are specific risk factors 3
- First-line antibiotic therapy is of no value because of the low risk of invasive bacterial infection (Grade C) 1
- In specific situations (high fever ≥38.5°C persisting for more than 3 days), consider antibiotics 1
2. Community-Acquired Pneumonia (CAP)
Requires prompt antibiotic therapy based on likely pathogens 1
For outpatient treatment in adults without risk factors:
For patients with risk factors (comorbidities, immunosuppression):
- Consider broader spectrum antibiotics: amoxicillin-clavulanate, parenteral 2nd or 3rd generation cephalosporin, or fluoroquinolone active against S. pneumoniae 1
3. Acute Exacerbation of Chronic Bronchitis
- For outpatient treatment:
Special Considerations
Influenza Treatment
- Antiviral therapy should be initiated within 36-48 hours of symptom onset for optimal effect 1
- Neuraminidase inhibitors (oseltamivir, zanamivir) are effective for both influenza A and B, with lower resistance rates compared to older agents 1
- These agents reduce clinical illness duration by approximately 2 days and can prevent secondary complications 1
Oxygen Therapy for Respiratory Distress
- Continuous oxygen therapy is indicated for patients with:
- PaO2 < 8 kPa
- Hypotension with systolic blood pressure < 100 mmHg
- Metabolic acidosis with bicarbonate < 18 mmol/l
- Respiratory rate > 30/min 1
- The aim should be to maintain PaO2 > 8 kPa or SaO2 > 92% 1
Common Pitfalls to Avoid
- Overuse of antibiotics for viral respiratory infections, which contributes to antibiotic resistance 3
- Delaying antibiotic therapy in suspected bacterial pneumonia, which is associated with increased mortality 1
- Failing to recognize the severity of illness and need for hospitalization in high-risk patients 1
- Not considering atypical pathogens (Mycoplasma, Chlamydia, Legionella) when standard therapy fails 1
- Using sputum Gram stain alone to guide initial therapy for community-acquired pneumonia, which has limited reliability 1
Monitoring Response to Treatment
- Evaluate response to initial therapy within 48-72 hours 1
- Treatment should not be changed within the first 72 hours unless the patient's clinical condition worsens 1
- For pneumonia, symptoms should begin to decrease within 48-72 hours of effective treatment 1
By following this structured approach to respiratory infections, clinicians can provide appropriate initial treatment while minimizing unnecessary antibiotic use and improving patient outcomes.