Treatment for Acute Respiratory Distress Syndrome
Treatment for ARDS is initiated as soon as possible to reduce the risk for death and to help prevent additional damage to the lungs and other organs. The goal is to treat the underlying condition and keep the patient alive and breathing.
Mechanical Ventilation to Treat ARDS
In most cases, keeping the patient alive requires mechanical ventilation. With ARDS, the breathing muscles (i.e., diaphragm and other muscles in the chest) become fatigued very quickly and can stop working in their effort to get oxygen into the body. The level of oxygen in the blood drops rapidly to dangerously low levels, causing damage to vital organs and body processes. If the oxygen level is not improved quickly and maintained at adequate levels, damage (including severe brain damage) can be irreversible. Mechanical ventilation keeps the level of oxygen at life-sustaining levels.
Once breathing is stabilized and blood is reoxygenated, the underlying condition is treated. For example, if the condition is pneumonia or a septic infection, the patient is treated with antibiotics.
Positive Pressure Ventilation to Treat ARDS
Mechanical ventilators deliver oxygen-rich air to the lungs and remove carbon dioxide from the body. The technique, also known as positive pressure ventilation, usually involves inserting an endotracheal tube into the trachea through the mouth or nose. The endotracheal tube passes through the upper airways, between the vocal cords, and into the trachea.
An inflatable balloon attached to the tube at the tracheal end prevents air from escaping through the upper airways and out of the body. The end of the tube outside of the body the is connected to a ventilator (machine that forces air into the lungs by providing positive pressure).
Normally, people breathe spontaneously by contracting the large dome-shaped muscle underneath the lungs (diaphragm). When the diaphragm contracts during inhalation, the dome deflates, the volume of the chest cavity increases, and negative pressure, or a partial vacuum, is created, bringing air into the lungs. When the diaphragm relaxes during exhalation, the dome rises, the volume of the chest cavity decreases, and air is pushed out of the lungs.
Positive pressure ventilation does two things:
- It pushes air into the lungs, relieving fatigued, nonfunctioning breathing muscles.
- It creates positive pressure in the alveoli, keeping them from collapsing and pushing fluid out of the alveolar spaces.
How long does a patient with ARDS need mechanical ventilation support?
Positive pressure ventilation is maintained until the patient can breathe independently at a normal rhythm. Some patients need support for only a few days and others may require it for months.
Health care practitioners often refer to taking a person off mechanical support as "weaning" them from the ventilator. Patients without a history of lung disease are usually weaned fairly smoothly. Difficult weaning may indicate complications, such as poor nutritional status, or an untreated or new infection.