At the Bedside
- Assess severity first: Work of breathing, SpO₂, mental status, hydration, sepsis physiology, pregnancy status, comorbidities.
- High-risk groups: Age <5 or >65, pregnancy/postpartum, chronic pulmonary/cardiac/renal/hepatic/metabolic disease, immunocompromise, neurologic disease, BMI ≥40, nursing home residents.
- Typical findings: Abrupt fever, chills, myalgias, headache, cough, sore throat, malaise. GI symptoms can occur, especially in children.
- Testing:
- PCR/NAAT is preferred if available; rapid antigen tests have lower sensitivity.
- Test if result will affect treatment, isolation, admission decisions, outbreak control, or high-risk exposures.
- Do not delay antivirals in high-risk or severely ill patients while awaiting testing.
- Evaluate complications when indicated:
- CXR for hypoxia, focal lung findings, persistent fever, severe cough, concern for pneumonia.
- Labs if ill appearing, septic, dehydrated, elderly, pregnant, or admitted: CBC, CMP, lactate, blood cultures if bacterial pneumonia/sepsis suspected.
- ECG/troponin if chest pain, arrhythmia, syncope, myocarditis concern.
- Initial ED management:
- Droplet precautions.
- Antipyretics, fluids, bronchodilators if wheezing, oxygen/ventilatory support as needed.
- Start antivirals for severe disease, hospitalization, high-risk patients, pregnancy, or symptom onset ≤48h.
- Treat suspected secondary bacterial pneumonia: especially if biphasic illness, focal infiltrate, purulent sputum, leukocytosis, shock.
- Disposition:
- Discharge if stable oxygenation, tolerating PO, reliable follow-up, no concerning comorbid decompensation.
- Admit for hypoxia, pneumonia, sepsis, altered mental status, inability to hydrate, pregnancy with complications, high-risk patient with clinical instability.
- ICU for respiratory failure, shock, severe myocarditis, encephalitis, or escalating oxygen needs.
Study Directive
- Memorize influenza high-risk categories and indications for antivirals beyond 48 hours.
- Practice disposition decisions using 3 mock cases: healthy young adult, pregnant patient, elderly COPD patient.
- Review local influenza testing and isolation policy.
- Write out adult antiviral doses from memory, including oseltamivir, baloxavir, zanamivir, and peramivir.
- Compare viral influenza pneumonia vs secondary bacterial pneumonia on timing, exam, and CXR findings.
Recent Literature
- Review or guideline Influenza
- Recent clinical Airway organoids reveal patterns of influenza A tropism and adaptation in wildlife species