Acute respiratory distress syndrome

Acute Respiratory Distress Syndrome (ARDS) is a respiratory system illness where fluid enters the air sacs in the lungs. ARDS was first described in 1967 by Ashbaugh et al. ARDS typically occurs in people who are already critically ill or who have significant injuries. Patient with ARDS usually have shortness of breath and chest pain and usually develops within a few hours to a few days. Many people who develop condition don't survive. The risk of death also increases depending age and other physical conditions. To those who do survive may have completely recovered, others have lasting damage to their lungs.

What is ARDS
Acute Respiratory Distress Syndrome (ARDS) is the build up of fluid in the alveoli or tiny air sacs in the lungs. The fluid in the lungs makes it strenuous to breathe and leads to low oxygen levels in the blood; The fluid also makes the lungs stiff and inelastic which causes your organs to receive less oxygen and increase the effort to breathe and get air into the lungs. A patient with ARDS will be placed on a ventilator to support them while the lungs heal. If the inflammation and fluid in the lungs worsen, then the patient will develop scarring in the lungs, which is known as the fibrotic stage of ARDS, also called pneumothorax. In this stage the lung can pop, and deflate and lead to a collapsed lung. ARDS occurs when there is significant trauma that either affects the lungs directly or indirectly. After a trauma the body could react with an inflammatory reaction that releases numerous natural molecules into the bloodstream. Usually this inflammatory reaction would be protective and help you fight infection or heal from an injury. However, in some people, these inflammatory molecules lead the smallest blood vessels in the lungs to leak fluid. Fluid leaves these small vessels and goes into the alveoli. The alveoli are full with this fluid, making it difficult for oxygen to diffuse into the bloodstream.

Causes and Symptoms
ARDS can be cause by either direct or indirect injuries to the lung. The direct causes are Pneumonia(lung inflammation caused by bacterial or viral infection, in which the air sacs fill with pus and may become solid), some causes are breathing vomit into the lungs (aspiration), lung transplant, and trauma. Examples of Trauma are breathing in smoke from a house fire, near-drowning, sepsis (Blood infection), or any cause of shock. The Indirect causes are Septic shock (infection throughout the body), blood transfusions, burns, and medication reactions. While ARDS is not common there are risk factors that could increase the risk of ARDS like a history of cigarette smoking, oxygen use for a pre-existing lung condition, recent high-risk surgery, Obesity, low protein in the blood, alcohol abuse, or recent chemotherapy (the treatment of disease by the use of chemical substances, especially the treatment of cancer by cytotoxic and other drugs).

The first symptoms of ARDS usually develop within 24 to 48 hours of the injury or illness. Symptoms may include difficulty breathing, low blood pressure and organ failure, rapid breathing, or shortness of breath. Patients with ARDS may also experience chest pain during inhalation, and bluish coloring of nails and lips due to very low oxygen levels in the bloodstream.

Diagnosing and Treating ARDS
ARDS is diagnosed based on your symptoms, vital signs, and a chest X-ray. There is no single test to determine that some one has ARDS. Since ARDS and some heart problems have similar symptoms, your doctor will have to perform chest X-rays cause it will show fluid present in both lungs.

Since there is no direct cure for ARDS, patient with ARDS will receive oxygen therapy and special treatment while their lungs heal:

Ventilator support
Patients with ARDS will be attached to a ventilator. The ventilator will help deliver oxygen through a tube inserted into the trachea or windpipe.

Prone positioning
To help improve oxygen levels in the blood and increase survival, patients will be ask to lie face down or prone. This task is very complicated and requires an entire team of medics to accomplish. Sometimes the patients may be too sick for this treatment. There are special beds designed to help position patients in intensive care though it is not a necessity.

Sedation and medications to prevent movement
After a while a patient may feel uncomfortable and painful when being supported by a ventilator. This leads to an intolerable feeling which leads to restlessness and agitation, which could cause even more problems for the lungs. To prevent this, the patient may need sedation to remain calm. The patients will receive medications called paralytics that can temporarily prevent movement.

Fluid management
Another treatment a patient with ARDS will receive is a medication called diuretic to help increase urination. Urination can help remove fluid from the body and can prevent more fluid from building up in the lungs. However too much fluid removal can lead to low blood pressure or kidney problems.

ECMO
Extracorporeal membrane oxygenation or ECMO is a very complicated treatment. ECMO takes blood outside of one's body and pumps it through a membrane that adds oxygen and removes carbon dioxide and then returns the blood to your body. This treatment has high risk and is not suitable for all patient.

Video
Quick description of ARDS. IOj-4oH9ROY