Respiratory

As we breathe, oxygen in the air is brought into the lungs and into close contact with the blood, which absorbs it and carries it to all parts of the body. At the same time, the blood gives up carbon dioxide, which is carried out of the lungs with air breathed out.

Lungs are not affected by paralysis. However, the muscles of the chest, abdomen, and diaphragm can be affected. As the various breathing muscles contract, they allow the lungs to expand, which changes the pressure inside the chest so that air rushes into the lungs. This is inhaling – which requires muscle strength. As those same muscles relax, the air flows back out of your lungs, and you exhale.

If paralysis occurs at the C-3 level or higher, the phrenic nerve is no longer stimulated and therefore the diaphragm does not function. This means mechanical assistance -- usually a ventilator – will be needed to breathe.

Persons with paralysis at the mid-thoracic level and higher will have trouble taking a deep breath and exhaling forcefully. Because they don’t have use of abdominal or intercostal muscles, these people have also lost the ability to forcefully cough. This can lead to lung congestion and respiratory infections.

Moreover, secretions can act as glue, causing the sides of your airways to stick together and not inflate properly. This is called atelectasis, or a collapse of part of the lung. Many people with paralysis are at risk for this. Some people have a harder time getting rid of any colds or respiratory infections and have what feels like a constant chest cold. Pneumonia is a possibility if secretions become the breeding ground for various bacteria.

A useful technique is the assisted cough: an assistant firmly pushing against the outside of the stomach and upwards, substituting for the abdominal muscle action that usually makes for a strong cough. This is much gentler than the Heimlich maneuver and it's important to coordinate pushes with natural breathing rhythms.

Another technique is percussion: this is basically a light drumming on the ribcage to help loosen up congestions in your lungs.

Postural drainage: This uses gravity to drain secretions from the bottom of your lungs up higher into your chest where one can either cough them up and out, or get them up high enough to swallow. This usually works when the head is lower than the feet for 15 or 20 minutes.

Ventilator users with tracheostomies need to have secretions suctioned from their lungs on a regular basis; this may be needed anywhere from every half hour to only once a day.

Ventilators

There are two basic types of mechanical ventilator. Negative pressure ventilators, such as the iron lung, create a vacuum around the outside of the chest, causing the chest to expand and suck air into the lungs. Positive pressure ventilators, which have been available since the 1940s, work on the opposite principle, by blowing air directly into the lungs.

A small face mask can also be used over the nose and/or the mouth for positive pressure ventilation. For patients who need breathing assistance only part of the time, such non-invasive means offer a way to avoid the complications associated with tracheostomies.

Another technique breathing involves the implantation of an electronic device in the chest to stimulate the phrenic nerve and send a regular signal to the diaphragm, causing it to contract and fill the lungs with air. Phrenic nerve pacers have been available since the late 1950s but are expensive and are not widely used.

Tracheostomy care

There are many potential complications related to tracheostomy tubes, including the inability to speak or swallow normally. Certain tracheostomy tubes are designed to direct air upward during exhalation and thus permit speech during regular, periodic intervals.

Another tracheostomy-associated complication is infection. The tube is a foreign body in the neck, and has the potential of introducing organisms that would ordinarily be stopped by natural defense mechanisms in the nose and mouth. Cleaning and dressing of the tracheostomy site on a daily basis is an important preventive measure.

Sources:

Craig Hospital, University of Miami School of Medline, University of Washington School of Medicine/Department of Rehabilitation Medicine.