What is ARDS?
Acute Respiratory Distress Syndrome (ARDS) refers to intense, severe injury to both lungs. It is not an actual disease, but rather a side effect of other diseases and conditions (eg: pneumonia, shock, sepsis, and trauma). ARDS may begin in one lung, but will quickly spread to the other.
ARDS usually develops 24 to 48 hours after an injury or illness affects the lungs. The severity of the symptoms vary from patient to patient. The alveoli (the parts of the lungs responsible for the oxygen/carbon dioxide switch) become inflamed or are damaged and collapse or lose their ability to take in oxygen. Within a day or two, a patient will experience respiratory failure.
Over the next few days, the lung will fill with inflammatory cells, and scarred tissue will start developing after about 10 days and get progressively worse - further compromising the lungs' ability to oxygenate the blood and remove carbon dioxide.
Death is usually due to the underlying disease or condition or from complications from ventilation. Patient who survive will see full lung function return within 6 to 12 months.
"According to the American Lung Association, the incidence of ARDS ranges from 1.5 to 71 per 100,000 persons in the United States" (www.pulmonologychannel.com).
Causes of ARDS
ARDS develops as the result of damage to lung tissues through a variety of conditions, so there is no one set of circumstances that will lead to ARDS. Experiencing any one of these circumstances doesn't necessarily mean that a patient will develop Acute Respiratory Distress Syndrome.
Some of those situations where ARDS may develop include:
- aspiration of vomit into the lungs
- inhalation of chemicals
- bacterial, fungal and viral pneumonia
- septic shock (sepsis)
- trauma, particularly multiple fractures, head injury, or injury to the chest
- blood transfusion (multiple units)
- near drowning
- drug overdose
- acute pancreatitis
ARDS can happen in conjunction with failure of other organ systems. Those who smoke or drink alcohol may be at increased risk or experience longer recovery times. Some treatments may not be as effective.
Symptoms and Treatment of ARDS
Pulmonologychannel.com lists the following signs, symptoms, and complications associated with ARDS.
- audible, labored breathing, shortness of breath
- abnormally fast breathing
- severe decrease of oxygen concentration in the blood
- pulmonary hypertension
- bluish coloring to skin due to lack of oxygen
- presence of abnormal deposits in the lungs (usually confirmed on chest X-rays)
Some of the potential complications of ARDS include multiorgan failure, since the inflammatory process that injured the alveoli and capillaries can also damage other organs, and irreversible pulmonary fibrosis, which can lead to long-term need for mechanical ventilation and a decrease in the ability of the lungs to expand and swap carbon dioxide for oxygen.
Usually, people that experience ARDS are already hospitalized for evaluation or treatment of underlying medical conditions. Treatment generally requires mechanical ventilation. This is important in keeping the diaphragm and other breathing muscles working, as they might get tired from the stress of trying to get limited amount of oxygen to the rest of the body. Mechanical ventilation will keep the blood and other organs properly oxygenated so that healing from the primary medical condition can continue. Ventilation also inhibits the collapse of the alveoli due to positive pressure in the lungs.
With effective treatment, 60 percent of ARDS patients recover and return to productive lives.
Sources: www.pulmonologychannel.com; www.nlm.nih.gov; www.emedicinehealth.com; www.ards.org;