Respiratory

Respiratory failure

Respiratory failure means that a patient is unable to breathe normally on their own. When patients are unable to breathe normally, the body may lack oxygen. They may also experience a build-up in their blood of carbon dioxide – a gas that is usually eliminated. Low levels of oxygen or high levels of carbon dioxide can cause severe complications and even death if not treated properly. Many medical conditions can lead to respiratory failure. Some of these conditions are directly related to the lungs, such as:

• Asthma;
• Chronic Obstructive Pulmonary Disease (COPD);
• Pneumonia (lung infection);
• Pulmonary edema (water on the lungs);

Other conditions leading to respiratory failure relate to other organs and systems of the body, such as:

• A failure of the nerves and muscles involved in breathing and coughing;
• A life-threatening infection;

Oxygen levels

Monitors can detect how much oxygen is in the blood. Although values above 92-94% are considered normal, the team frequently allows for lower values, such as 88%, without any detriment to the patient.

When patients develop respiratory failure, they may require help to normalize the exchanges of oxygen and carbon dioxide in their body. Extra, or supplemental, oxygen can be given through nasal prongs or a mask. When respiratory failure is severe, a breathing machine (mechanical ventilation) is sometimes required to give patient’s lungs and body the time to recover from their illness.

What is a breathing machine (mechanical ventilator) and what does it do?

Some patients need help to breathe. When a patient needs help breathing, a “breathing machine” – also known as a mechanical ventilator is used to replace the function of the lungs. To use a mechanical ventilator, access to the patient’s lungs must be secured, either through a tube inserted into the mouth or nose (intubation) or a tube inserted into the windpipe (tracheostomy). This allows the ventilator to blow air into the lungs and maintain proper oxygen levels in the blood.

Mechanical ventilators are complex machines that can be adjusted to meet the needs of each patient. Respiratory therapists and physicians use protocols or guidelines to adjust the controls throughout the day to improve the patient’s comfort and maintain oxygen levels within normal limits.

Each person has a different perception and response to the discomfort caused by the breathing tube and machine. One out of every 3 patients will not even remember being intubated.

Using a breathing machine is considered a form of life support. The machine does not "fix" the underlying problem, but improves gas exchanges and decreases the work of breathing done by patients until their condition improves. It is often difficult to predict how long a patient will need the breathing machine. It will depend on several factors, including:

• The nature and severity of the medical problem that led to the respiratory failure;
• The general condition of the patient before the respiratory failure;
• If any new complications emerge after the patient goes on the breathing machine.

Before mechanical ventilation is stopped, three conditions usually need to be met:

• Patients need to be awake enough to start each breath (their brain must tell them to breathe consistently) and to cough properly;
• Patients need to maintain acceptable levels of oxygen and carbon dioxide with minimal help from the breathing machine. This indicates that they are likely to be able to breathe without the machine;
• The medical problem that led to the need for the breathing machine must have improved significantly. This may be relatively easy to assess if the initial problem was related to just the lungs. But it may be harder to determine if the problem was related to something else such as airway swelling or generalized severe weakness.

Treating the cause of respiratory failure is the best way for coming off the machine. But other things can be done to help patients come off the ventilator quicker:

• Avoiding excessive sedation;
• Start patients moving about as soon as it is safe - even if they are still breathing on the machine
• Checking if they can breathe by themselves on a daily basis;
• Avoiding excessive fluids in their body when possible.

Like any medical intervention, the breathing machine may cause certain complications. Long periods of mechanical ventilation can be associated with mouth, vocal cords and throat injuries, lung infections, and muscle and general weakness and fatigue.