What are mitochondrial respiratory disorders?

Respiratory problems may occur when mitochondrial disease impairs the function of muscles that control breathing or swallowing. Weakness in these muscles can make it difficult to swallow properly or clear the airway by effective coughing. Recurrent pneumonia results when secretions collect in the lungs, or when difficulty swallowing leads to inhalation (aspiration) of food or liquid into the lungs.

Mitochondrial respiratory disorders may also cause oxygen levels to drop during sleep. Muscles that are too weak to keep the airway open at night causes a condition called obstructive sleep apnea. Central sleep apnea may also occur when mitochondrial disease involves brain regions that control breathing. Blood oxygen levels may also drop at night when respiratory muscles are not strong enough to breathe sufficient air into the lungs.

What are the symptoms of mitochondrial respiratory disorders?

The symptoms of pneumonia may include:

• Fever
• Productive cough
• Pain in the chest
• Decrease in appetite
• Chills
• Vomiting
• Headache

The symptoms of low blood oxygen levels during sleep may include:

• Snoring
• Periods of not breathing at night
• Decreased activity during the day
• Decreased endurance

Testing and diagnosis for mitochondrial respiratory disorders

Depending on your child’s symptoms, your child may have their blood oxygen level tested and the following diagnostic procedures performed:

• Chest X-ray
• Pulmonary function test to determine how well your child’s lungs work
• Modified barium swallow study to determine how effectively and safely your child swallows liquids and foods of different textures
• An overnight sleep study to monitor the quality and quantity of your child’s sleep

Treatment for mitochondrial respiratory disorders

Your child’s treatment will be determined by the type and severity of the respiratory disorders. Treatment may include one or more of the following:

• Breathing support at night, delivered through a continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BPAP) nasal mask
• Therapies and medication to clear the airways
• Speech or occupational therapy to support effective swallowing

Children with severe aspiration may require a gastrostomy tube (G-tube), which is a plastic tube surgically inserted through the abdominal wall that allows delivery of liquids, nutrition and medications directly into the stomach.

Follow-up care for mitochondrial respiratory disorders

Long-term care for children and adults will be determined by the severity of the mitochondrial respiratory disorder. Mitochondrial Medicine at Children’s Hospital of Philadelphia (CHOP) uses a multidisciplinary approach in caring for patients with mitochondrial respiratory disorders. In addition to a pulmonologist, your care team may include physical, occupational and speech therapists, social workers, registered dieticians, respiratory therapists, neuromuscular disease specialists, and a multi-disciplinary team of other healthcare professionals.