Course 04: Respiratory Medicine and Infectious Disease
Lesson 6 of 14. Explore the diagnostic and management frameworks, work through the case, and finish the linked 10-question practice set. Urgent presentations require an emergency-care pathway and review of local professional scope.
Differentiating respiratory infections
- Pneumonia often causes fever, cough, tachypnea, pleuritic pain and focal lung findings; a chest radiograph or expert ultrasound may support diagnosis where appropriate.
- Uncomplicated acute bronchitis is commonly viral; routine antibiotics offer little benefit and cause harm; consider pneumonia or pertussis based on risk and course.
- Rhinosinusitis and pharyngitis are often viral: evaluate bacterial features, group A strep criteria, deep neck infection, airway compromise and epiglottitis red flags.
Severity and investigation
- Determine stability, oxygenation, ability to eat/drink, immune suppression, chronic disease and frailty; use validated severity tools as decision aids, not substitutes for judgment.
- Obtain appropriate cultures in selected hospitalized/severe cases before antibiotics when feasible, without delaying care in sepsis.
- Severe hypoxemia, confusion, hypotension, multilobar involvement or inability to maintain oral intake requires emergency or inpatient assessment.
Antimicrobial decisions
- Empiric choices depend on CAP severity, age, comorbidities, allergy, recent antibiotics, local resistance and clinical context; follow local stewardship pathways.
- Positive viral testing does not automatically settle the antibiotic decision: ATS 2025 CAP update differentiates low-risk outpatients from patients with higher clinical risk.
- Reassess at 48-72 hours when clinically appropriate, review microbiology and narrow/stop therapy when safe; duration depends on clinical stability and current guidance.
Complications and prevention
- Consider pleural effusion/empyema, bacteremia, respiratory failure and sepsis in nonresolving or complicated infection.
- Post-pneumonia imaging may be indicated in high-risk patients or persistent symptoms; it is not required routinely for every patient.
- Seasonal vaccines, smoking cessation, hand hygiene and prevention of aspiration reduce risk.
Applied clinical case
A 78-year-old with fever and cough is newly confused, respiratory rate 32 and oxygen saturation 86% on room air.
Show model clinical reasoning and disposition
This is severe potential pneumonia with hypoxemic respiratory failure/sepsis. Arrange immediate emergency-level evaluation and stabilization; home antibiotics alone are unsafe.
Clinical self-check
- What distinguishes acute bronchitis from pneumonia?
- How do severity and comorbidity affect antibiotics?
- When is repeat imaging useful?
Current guidance and further learning
- ATS: 2025 update to adult community-acquired pneumonia guideline (external)
- IDSA/ATS: Adult community-acquired pneumonia guideline 2019 (external)
- Surviving Sepsis Campaign 2026 adult guideline (external)