Paralyzed Diaphragm

What is a paralyzed diaphragm?

The diaphragm is a muscle that separates the chest and abdominal cavities. It is controlled by the phrenic nerve.

Diaphragm paralysis is uncommon. Whether the paralysis occurs in one (unilateral) or both (bilateral) sides of the diaphragm, all patients will experience some amount of reduction in lung capacity. This is most severe with bilateral diaphragm paralysis. Unilateral diaphragm paralysis commonly has no symptoms. However, if unilateral diaphragm paralysis occurs in patients with significant heart or lung disorders, symptoms can become evident.

What are causes and risk factors for a paralyzed diaphragm?

The causes and risk factors that compromise diaphragmatic function include:

What are the symptoms of a paralyzed diaphragm?

Symptoms of significant, usually bilateral diaphragm weakness or paralysis are shortness of breath when lying flat, with walking or with immersion in water up to the lower chest. Bilateral diaphragm paralysis can produce sleep-disordered breathing with reductions in blood oxygen levels.

Newborns and children with unilateral diaphragmatic paralysis may experience more severe respiratory distress than adults, due to weaker muscles and a more compliant chest wall. The newborn may have a weak cry or show signs of gastrointestinal distress, with frequent vomiting. Children with bilateral diaphragmatic paralysis require immediate medical attention and ventilator intervention because the condition can be life-threatening.

Patients with bilateral diaphragmatic paralysis may experience a 70-80 percent reduction in lung capacity while patients with unilateral diaphragmatic paralysis may experience a 50 percent reduction.

How is a paralyzed diaphragm diagnosed?

Diagnosis of diaphragmatic paralysis usually begins with a physical exam and a review of the patient's medical history and symptoms. On examination, with the patient lying flat, the abdominal wall moves inward during inhalation (instead of the normal outward movement). This is called paradoxical motion.

Tests include:

  • Lung function tests, including some tests done sitting and lying down
  • Chest X-ray
  • Radiologic fluoroscopy (real-time viewing) with a sniff maneuver to show paradoxical motion
  • Ultrasound imaging to look at diaphragm motion and changes in the muscle thickness
  • Maximum inspiratory mouth pressures (measure of breathing muscle strength)
  • Measure of transdiaphragmatic pressure (measure of diaphragm strength)
  • Phrenic nerve stimulation in the neck by electric or magnetic stimulation
  • Electromyography, a test that evaluates and records electrical activity produced by skeletal muscles
  • Arterial blood gas test; an abnormal result is a late sign of severe impairment
  • Computed tomography scanning of the chest, abdomen or both
  • Magnetic resonance imaging to determine if there is an underlying condition involving the spinal column or nerve roots
  • Ultrasound to see the activity of the diaphragm and to identify any unusual movement or lack of movement

How is a paralyzed diaphragm treated?

Physicians take into consideration the overall health of the patient, the severity of symptoms, the duration of diaphragm paralysis, other conditions, and any underlying cause for the paralysis. Treatment options include:

  • Observation with or without supportive treatment (if the patient has no symptoms or the symptoms are mild, and the patient is in otherwise good health or there is a chance that recovery can occur spontaneously).
  • Noninvasive ventilatory assistance, particulary at night.
  • Diaphragmatic plication, a surgical procedure that pulls the diaphragm down by introducing a repeated series of continuous sutures across the diaphragm and pulling the muscle taut. This procedure is used in patients with unilateral paralysis (and occasionally bilateral). The surgery allows the lung to expand better and improve ventilation. Plication is usually done by minimally invasive means.
  • Diaphragm pacemakers, which may be used in patients who have functioning phrenic nerves, such as patients with ALS or spinal cord injury. The devices may result in improved respiratory function and lower infection rates.
  • A tracheostomy and mechanical ventilation, the surgical formation of an opening in the trachea, which helps allow the passage of air. This approach is commonly used for patients with a life-threatening disease or a diagnosis of high quadriplegia.

The prognosis for unilateral paralysis is good, providing there is no underlying significant pulmonary or cardiac disease. Some patients recover without medical intervention. The prognosis for bilateral paralysis also depends on the overall health of the patient, but surgery may be the best option for patients who continue to have a poor quality of life.

Some lung conditions can be difficult to diagnose, and it is important for patients to seek medical attention from a specialist who is familiar with diaphragm weakness or paralysis. The staff at the Women's Guild Lung Institute works as a team to determine the best treatment option for each patient.

Key points

  • The diaphragm is a muscle that separates the chest and abdominal cavities. Paralysis of this muscle is uncommon.
  • Causes and risk factors include cancer, traums and neuromuscular disorders.
  • Treatment options run from observation to ventilatory assistance to surgery.
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