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Post-Polio breathing and sleep problems

Written by: Judith R. Fischer and Joan L. Headley, International Polio Network

New breathing and sleep problems in aging polio survivors can be insidious and often is not recognized by either polio survivors themselves or health care professionals. Polio survivors who were in an iron lung or barely escaped one during the acute phase should be aware of potential problems and educate themselves in order to avoid acute respiratory failure. Polio survivors who did not need ventilatory assistance during the acute phase may also be at risk for respiratory failure and should likewise be aware of problems with breathing and sleep.

Simply stated, the major problem for polio survivors is hypoventilation (commonly referred to as underventilation). Not enough air reaches the lungs, producing an imbalance in the gas exchange in the blood: too little oxygen, too much carbon dioxide (CO2) or hypercapnia. Hypoventilation is caused by one or a combination of the following: chest wall deformities such as scoliosis, respiratory muscle weakness due to the poliomyelitis, and sleep apnea (an interruption of breathing during sleep) which can be central obstructive, or mixed, and occurs in the general population as well.

Other factors contributing to a polio survivor's problems are a history of smoking, obesity, lung disease, and diminished vital capacity. As aging occurs in anyone, vital capacity diminishes, but this decrease in vital capacity is more serious in an aging polio survivor with limited musculature remaining to produce adequate ventilation. Many polio survivors had impairment of the diaphragmatic and intercostal muscles, and the normal changes due to aging may cause them to lose vital capacity at a greater rate, thus exacerbating the development of hypoventilation.

Signs and symptoms include: fatigue, daytime sleepiness, morning headaches, need to sleep sitting up, sleep disturbances (including dreams of being smothered, nightmares, restless sleep, interrupted sleep), snoring, poor concentration and impaired intellectual function, shortness of breath on exertion, claustrophobia and/or feeling that the air in the room is somehow bad, anxiety, difficulty in speaking for more than a short time, quiet speech with fewer words per breath, use of accessory muscles to breath, and a weak cough with increased susceptibility to respiratory infections and pneumonia.

Polio survivors experiencing more than one of the above signs and symptoms should seek a respiratory evaluation by a pulmon-ologist, preferably one experienced in chronic neuromuscular disorders. Pulmonary function tests should include at least: vital capacity, airflow, maximum inspiratory force) and maximum expiratory force, and arterial blood gases. A sleep study should also be considered, however, strong anecdotal evidence from polio survivors indicates that a sleep study may miss detecion of hypoventilation. A sleep study is designed to detect sleep disturbances, such as sleep apnea: it does not measure CO2.

Management of breathing and sleep problems can be achieved largely through the use of nocturnal noninvasive ventilation, in the form of mouth intermittent positive pressure ventilation, nasal intermittent positive pressure ventilation (a variety of commercial and custom nasal/face masks are available), and negative pressure body ventilators. However polio survivors may find themselves gradually extending periods of ventilator use. In some cases, as a last resort, invasive tracheotomy positive pressure may be necessary.

Medical literature regarding the management of breathing problems often includes a warning about the use of oxygen therapy. Respiratory failure in polio survivors is usually due to hypoventilation which can be aggravated by the short and long term use of oxygen. When the brain senses an excess concentration of CO2 in the blood it instructs the body to increase breathing, ridding it of the CO2 and increasing the oxygen. When oxygen is supplied, the mechanism in the brain detecting the CO2 eventually turns off. Hypercapnia is best treated with assisted ventilation.

Polio survivors with different problems, such as chronic obstructive pulmonary disease or pneumonia, may benefit from short term oxygen therapy under careful supervision.