Medical Blog | Pulmonary Complications of Influenza A: How Handheld Ultrasound Can Help with Diagnosis and Monitoring

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In recent days, the risk of catching the flu has increased due to dropping temperatures.
The long lines for flu vaccinations every year are a testament to how seriously people take it—especially after reports of well-known individuals passing away due to flu-related pneumonia and other complications.

Winter is the season for Influenza, flu is still ongoing, affecting people of all ages. The flu has a short incubation period of 1 to 4 days and spreads easily. Compared to a common cold, flu symptoms tend to be more severe. High-risk groups, such as the elderly, children, and individuals with chronic illnesses, are more likely to develop complications like pneumonia, encephalitis, myocarditis, or even face life-threatening situations.

What Is Influenza? What Are Its Main Symptoms?

Influenza A is a highly contagious viral infection that spreads most rapidly during winter. Symptoms include high fever, muscle aches, sore throat, and coughing. For high-risk individuals, Influenza A can lead to serious lung complications such as viral pneumonia, bacterial pneumonia, and pulmonary edema. In severe cases, it may even progress to Acute Respiratory Distress Syndrome (ARDS).

How Does the Flu Cause Complications?

Pneumonia

When the flu virus infects the body, it can attack the lungs directly, leading to viral pneumonia. This can cause congestion and fluid buildup in the lungs, making it difficult to breathe.

Pulmonary Edema

A secondary bacterial infection can worsen the condition, filling the air sacs with fluid and impairing oxygen exchange, leading to pulmonary edema. If left undiagnosed and untreated, these complications can escalate quickly, becoming life-threatening.

The Role of POCUS in Flu Diagnosis and Treatment

While diagnosing the flu itself doesn’t require ultrasound, Point-of-Care Ultrasound (POCUS) is extremely valuable when complications like pneumonia, pulmonary edema, or ARDS arise. Compared to X-rays and CT scans, handheld ultrasound provides a faster, more flexible bedside imaging option—making it particularly useful in emergency rooms, ICUs, and clinics.

  1. Pulmonary Edema and B-lines

    Handheld ultrasound can detect B-lines, a key indicator of lung fluid accumulation. When fluid builds up in the alveoli, ultrasound images will display multiple bright vertical streaks, signaling the possibility of pulmonary edema.

  2. Pneumonia and Lung ConsolidationPneumonia-related lung damage appears as consolidation areas on ultrasound images, showing fluid-filled alveoli. This helps doctors assess the extent and severity of the infection.
  3. Pleural EffusionBacterial infections secondary to the flu can cause fluid buildup in the pleural cavity. Ultrasound is effective in distinguishing exudative pleural effusion (caused by infection or inflammation) from transudative effusion (caused by conditions like heart failure). This helps doctors determine whether drainage is needed.
  4. Critical Care, Emergency, and Pre-Hospital Settings
    • Monitoring Respiratory Deterioration: For severe flu patients in the ICU, POCUS can track worsening respiratory conditions and help doctors decide whether intubation or mechanical ventilation is necessary.
    • Quickly Identifying Causes: In emergency situations, POCUS helps differentiate whether flu-related breathing difficulties stem from pneumonia, pulmonary edema, or another cause.

Why Use Handheld Ultrasound for POCUS?

Point-of-Care Ultrasound (POCUS) is a crucial diagnostic tool that allows real-time assessment at the bedside. It is especially useful for:

  • Quickly diagnosing pulmonary edema, pneumonia, and pleural effusion
  • Providing fast, non-invasive imaging in critical care settings
  • Serving as a cost-effective and accessible solution in remote areas, small clinics, or developing countries

While handheld ultrasound may not be as powerful as traditional ultrasound machines, its portability and convenience make POCUS more accessible and practical for widespread use.

(Further reading : ICEM 2024 Showcases Advantages of Apache Handheld Wireless Ultrasound for POCUS Applications)

How Does Handheld Ultrasound Compare to X-ray and CT?

  1. No Radiation
    Unlike X-rays or CT scans, ultrasound is radiation-free and safe for children, pregnant women, and elderly patients. It can also be used multiple times to track disease progression without concern for radiation exposure.
  2. Quick Lung Assessment for Flu Complications
    Handheld ultrasound can quickly scan for B-lines, pleural effusion, and lung consolidation—all key indicators of flu-induced pneumonia or pulmonary edema.
  3. Real-Time Bedside Diagnosis, Faster Clinical Response
    By providing instant imaging at the bedside, handheld ultrasound reduces diagnostic delays, speeds up clinical decision-making, and lowers the risk of cross-infection. This is especially beneficial for critically ill patients who cannot be easily moved to a radiology department for CT scans.

Enhancing Flu Season Diagnosis with Handheld Ultrasound

During flu season, rapid diagnosis and real-time lung monitoring are essential. Advancements in handheld ultrasound technology allow clinicians to quickly and accurately assess flu patients’ lung conditions, reducing complication rates and improving treatment outcomes.

With AI-assisted imaging and ongoing ultrasound advancements, handheld devices will likely become an indispensable diagnostic tool for hospitals and clinics in the near future.
(Related Reading: Apache neo C62 Handheld Ultrasound)

Six Key Tips to Fight the Flu

  1. Get the flu vaccine
  2. Maintain good personal hygiene
  3. Wear a mask and practice social distancing
  4. Strengthen your immune system
  5. Maintain a clean environment
  6. Seek medical attention immediately if symptoms appear

References data
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