The cause of ARDS is not well known. Current scientific information supports several theories about its development, but the precise reason ARDS occurs remains unknown. What is known, however, is that ARDS can come about by either of two basic mechanisms.
The first is a direct physical or toxic injury to the lungs. Examples include inhalation of vomited stomach contents (aspiration), smoke or other toxic fumes, and a severe 'bruising' of the lungs that usually occurs after a severe blow to the chest.
The second mechanism is more common, but less understood. This is an indirect, blood-born injury to the lungs. When a person is very sick or the body is severely injured, some chemical signals are released into the bloodstream. These signals reach the lung, and the lung reacts by becoming inflamed, thus causing lung failure. Examples of this type of indirect lung injury include the presence of severe infection (sepsis) and severe injury (trauma) - the two most common factors in ARDS cases. Other examples are severe bleeding (resulting in massive blood transfusions), severe inflammation of the pancreas (pancreatitis) and some types of drug overdoses.
ARDS has generally been characterized into three stages. In full-blown cases, these three stages unfold sequentially over a period of several weeks to several months.
1 Exudative stage: Characterized by accumulation in the alveoli of excessive fluid, protein and inflammatory cells that have entered the air spaces from the alveolar capillaries. The exudative phase unfolds over the first 2 to 4 days after onset of lung injury.
2 Fibroproliferative (or proliferative) stage: Connective tissue and other structural elements in the lungs proliferate in response to the initial injury. Under a microscope, lung tissue appears densely cellular. Also, at this stage, there is a danger of pneumonia sepsis and rupture of the lungs causing leakage of air into surrounding areas.
3 Resolution and Recovery: During this stage, the lung reorganizes and recovers. Lung function may continue to improve for as long as 6-12 months and sometimes longer, depending on the precipitating condition and severity of the injury. It is important to remember that there may be and often are different levels of pulmonary recovery amongst individuals who suffer from ARDS.
Treatment primarily involves supportive care in an intensive care unit (ICU), including use of a mechanical ventilator (vent) and supplemental oxygen. The goal of mechanical ventilation is to support the patient's breathing during the time needed for the patient's lungs to heal. Good progress has been made recently in improving the use of ventilators.The seriousness and unpredictability of ARDS can emotionally devastate patients, family, friends, as well as doctors and nurses, especially since very few cases of ARDS are alike. Some patients get better quickly within several days, and others take weeks or months to improve. Some patients have no complications and others seem to develop every possible complication of ARDS. Finally, some victims die quickly, while others die after a long and trying illness.
While ARDS is a very serious syndrome, people can and do survive! It is important family and friends of the patient remain hopeful, and seek guidance from others, including ARDS survivors, families and friends of survivors.
From Matt:
Statistically over 60% of ARDS patients survive and although that might be daunting it is important to note that the underlying causes of this syndrome are yet to be determined. When it was first defined in the late 1960's it was 100% fatal. I am grateful that we live in a time where medical science can give us 60% and family powerful in the spirit to make up the 40% we need.
My experiences with Colton have been marked by a deep respect and love for him. He (and his brothers) are much finer men then I ever was at that age. When someone complains about teenagers not living up to the standards set by the generations that preceded them, I always think of the Stewart boys and the great kindness they continue to share with those around them especially to my parents. My heart and continued respect goes out to Colton and his family whom I love deeply.
Sources and resources:
http://www.ards.org/learnaboutards/whatisards/brochure/
http://en.wikipedia.org/wiki/Acute_respiratory_distress_syndrome
http://www.ardsusa.org/facts.htm
