What are the recommendations for managing persistent or worsening cough in patients with flu symptoms, including the use of chest x-rays?

Management of Flu Symptoms and Persistent Cough

For patients with persistent or worsening cough after flu diagnosis, a clinical reassessment should be performed and a chest x-ray is recommended only if there are signs of pneumonia or other complications, not routinely for all flu-positive patients. 1

Symptoms of Influenza

• Flu is characterized by abrupt onset of fever (>38°C), cough, chills or sweats, myalgias, and malaise 2
• Other common symptoms include rhinitis, sore throat, and headache 3
• In uncomplicated cases, the illness typically resolves within seven days, although cough, malaise, and fatigue may persist for weeks 1

Management of Persistent or Worsening Cough

When to Reassess

• Patients who are not progressing satisfactorily with initial treatment should undergo a full clinical reassessment 1
• Persistent symptoms beyond the typical recovery period (7 days) warrant follow-up evaluation 1
• Worsening symptoms such as increasing shortness of breath, severe earache, vomiting for more than 24 hours, or drowsiness require prompt medical attention 1

Diagnostic Approach for Persistent/Worsening Cough

• A thorough clinical evaluation should be performed to assess for complications such as pneumonia 4
• Signs that suggest pneumonia or other complications include:
  • Focal chest signs 4
  • Dyspnea or tachypnea (respiratory rate >30/min) 4
  • Fever lasting >4 days 4
  • Bilateral chest signs or CRB-65 score of 3 or more 1

Chest X-ray Recommendations

• A chest x-ray is NOT routinely recommended for all flu-positive patients 1
• A chest x-ray should be obtained in the following circumstances:
  • When a patient is seen in a hospital setting (emergency department or acute admissions ward) with suspected complications 1
  • When pneumonia is clinically suspected based on respiratory symptoms and signs 4
  • When patients have bilateral hazy infiltrates, which may indicate primary viral pneumonia or bacterial pneumonia (considered a sign of potentially severe disease) 4
  • For patients who do not respond to empirical antibiotic therapy when bacterial infection is suspected 1

Follow-up Imaging

• In patients who have had a chest x-ray and are subsequently followed up in a hospital outpatient clinic or by a general practitioner, a repeat chest x-ray should be obtained at around six weeks if:
  • Respiratory symptoms or signs persist 1
  • There is a higher risk of underlying malignancy (especially smokers and those over 50 years of age) 1

Treatment Recommendations for Persistent Cough

Antiviral Therapy

• Consider antiviral treatment (neuraminidase inhibitors) if the patient:
  • Has an acute influenza-like illness with fever (>38°C)
  • Has been symptomatic for two days or less 1
  • Is at high risk for complications 3
• Treatment schedule for adults: oseltamivir 75 mg every 12 hours for five days 1
• The benefit is greatest when started within 24 hours of symptom onset 2

Antibiotic Therapy

• Antibiotics should be considered when bacterial co-infection is suspected, particularly in patients with:
  • Risk factors for complications of influenza 1
  • Worsening symptoms after initial improvement (suggesting secondary bacterial infection) 5
  • Signs of pneumonia 1
• Common bacterial pathogens in influenza-related pneumonia include Streptococcus pneumoniae, Staphylococcus aureus, and Haemophilus influenzae 1

Supportive Care

• Appropriate oxygen therapy for hypoxic patients to maintain PaO₂ >8 kPa and SaO₂ >92% 1
• Over-the-counter analgesics (paracetamol, ibuprofen) can help manage pain and fever symptoms 6
• Adequate hydration and nutritional support, especially in severe or prolonged illness 1

When to Consider Hospital Admission

• Consider hospital admission for patients with:
  • Bilateral lung infiltrates on chest x-ray (consistent with primary viral pneumonia) 1
  • CURB-65 score of 3 or more (high risk of death) 1
  • Two or more unstable clinical factors:
    • Temperature >37.8°C
    • Heart rate >100/min
    • Respiratory rate >24/min
    • Systolic blood pressure <90 mmHg
    • Oxygen saturation <90% 1

Indications for ICU/HDU Transfer

• Persisting hypoxia with PaO₂ <8 kPa despite maximal oxygen administration 1
• Progressive hypercapnia 1
• Severe acidosis (pH <7.26) 1
• Septic shock 1

Remember that early recognition and appropriate management of influenza complications can significantly reduce morbidity and mortality, particularly in high-risk patients.