A ventilator is a machine that is mainly used in hospitals to help people breathe. Ventilators gently push oxygen into the lungs and remove carbon dioxide (a waste gas that can be toxic) from the body. These machines are often used to breathe for people who have lost all ability to do so on their own, either temporarily or permanently.
A ventilator is often used for short periods, such as during surgery when a patient is under general anesthesia. The medicines used to induce anesthesia can disrupt normal breathing, so a ventilator is used to ensure the patient continues breathing during surgery. A ventilator may also be used during treatment for a serious lung disease or other condition that affects normal breathing.
Impaired Lung Function
A person may need to use a ventilator if a disease, condition or other factor has impaired their breathing. Although a patient may be able to breathe on their own, it's very hard work. They may feel short of breath and uncomfortable. A ventilator can help ease this process. People who can't breathe on their own at all also use ventilators.
Many diseases, conditions and other factors can affect lung function, including:
- Pneumonia and other respiratory infections
- Lung diseases like COPD (chronic obstructive pulmonary disease)
- Upper spinal cord injuries, polio, amyotrophic lateral sclerosis (ALS), myasthenia gravis and other diseases or factors that affect the nerves and muscles involved in breathing
- Brain injury
- Drug overdose
A ventilator can help a patient breathe until they recover. If a full recovery is not possible, then a ventilator may be necessary for the rest of a patient's life.
How a Ventilator Works
Ventilators gently blow air—or air with increased amounts of oxygen—into the airways and then the lungs. The airways are pipes that carry oxygen-rich air to the lungs and then carry carbon dioxide, a waste gas, out of the lungs.
The airways include:
- Nose and linked air passages, called nasal cavities
- Larynx, or voice box
- Trachea, or windpipe
- Tubes called bronchial tubes or bronchi, and their branches
A ventilator blows air into a patient's airways through a breathing tube. One end of the tube is inserted into the windpipe and the other end is attached to the ventilator. The process of placing the tube into the windpipe is called intubation.
Usually, the breathing tube is put into a patient's windpipe through the nose or mouth. The tube is then moved down into the throat. A tube placed like this is called an endotracheal tube.
Endotracheal Tube Ventilators
An endotracheal tube is held in place by tape or with an endotracheal tube holder. This often is a strap that fits around the head. Sometimes the breathing tube is put into the windpipe through a hole in the front of the neck. A surgeon makes the hole using a procedure called a tracheotomy. The tube put into the hole is sometimes called a "trach" tube.
Endotracheal tubes are mainly used for people who are on ventilators for shorter periods. The advantage of this tube is that it can be placed in an airway without surgery.
Trach tubes are used for people who need ventilators for longer periods. For people who are awake, this tube is more comfortable than the endotracheal tube. Under certain conditions, a person who has a trach tube may be able to talk.
What To Expect While on a Ventilator
A ventilator can be set to "breathe" a specific number of times per minute. Sometimes it's set so that the patient can trigger the machine to blow air into their lungs. If it is not triggered within a certain amount of time, the machine automatically blows air to keep continue breathing.
Rarely, a ventilator called a chest shell is used. This type of ventilator works like an iron lung—an early ventilator that was used by many polio patients in the last century. However, the chest shell isn't as bulky and confining as the iron lung. The chest shell fits snugly to the outside of one's chest. A machine creates a vacuum between the shell and the chest wall. This causes a patient's chest to expand and air is sucked into the lungs. No breathing tube is used with a chest shell. When the vacuum is released, the patient's chest falls back into place and the air in their lungs comes out. This cycle of vacuum and release is set at a normal breathing rate.
Ventilators normally don't cause pain. The breathing tube in the airway may cause some discomfort, however. It may also affect the ability to talk and eat. If the breathing tube is a trach tube, the person may be able to talk.
Instead of food, a patient may be given nutrients through a vein in their body while on a ventilator. Nasogastric feeding (also called tube feeding) is common for those who are on a ventilator long term. The tube goes through the nose or mouth or directly into the stomach or small intestine through a surgically made hole.
A ventilator greatly restricts activity and also limits movement. A person may be able to sit up in bed or in a chair, but they usually can't move around much. A portable ventilator machine may be available for long-term patients. This machine allows for greater ease of movement and patients can even go outside with one.
Risks Associated with Being on a Ventilator
People on ventilators should be carefully monitored by a health care team, including doctors, nurses and respiratory therapists. A patient may need periodic chest X-rays and regular blood tests to check the levels of oxygen and carbon dioxide (blood gases) in the body.
These tests will help the health care team find out how well the ventilator is working. Based on the test results, they may adjust the ventilator's airflow and other settings as needed.
Also, a nurse or respiratory therapist will need to suction out the breathing tube from time to time. Suctioning removes mucus from the lungs. This process will cause the person to cough and they may feel short of breath for several seconds.
Risks of Being on a Ventilator
One of the most serious and common risks of being on a ventilator is pneumonia. Ventilator-associated pneumonia (VAP) is linked to the breathing tube that's put in one's airway while on the machine. The tube may make it easy for bacteria to get into the lungs and difficult to cough. Coughing is important for helping to clear bacteria from the lungs and airways.
VAP is a major concern for people using ventilators because they're often already very sick. Pneumonia may make it harder to treat their original disease or condition. VAP is treated with antibiotics. Special antibiotics may be necessary if the VAP is due to bacteria that are resistant to standard treatment.
Another risk of being on a ventilator is sinus infection. This is more common in people who have an endotracheal tube. (This tube is put into the windpipe through the mouth or nose.) Sinus infections are also treated with antibiotics.
This is a condition in which air leaks out of the lungs and into the space between the lungs and the chest wall. This can cause pain and shortness of breath, and it may cause one or both lungs to collapse.
Pushing air into the lungs with too much pressure can harm the lungs.
High levels of oxygen can damage the lungs. These problems may occur because of the forced airflow or higher levels of oxygen from the ventilator.
Using a ventilator also increase one's risk for blood clots and serious skin infections. These problems tend to occur in people who have certain diseases and/or who are confined to a bed or a wheelchair and must remain in one position for long periods. Another possible problem is damage to the vocal cords from the breathing tubes. If it's hard for a patient to speak or breathe after the breathing tube is taken out, let the doctor know.
Source: The National Heart, Lung, and Blood Institute; https://www.nhlbi.nih.gov/