Definition
Acute Respiratory Distress Syndrome is an acute diffuse lung disease. It happens when fluid is filled with air sacs (alveoli) in your lungs. It leads to increased pulmonary vascular permeability; enormous fluid in the lungs will lower the oxygen level in your bloodstream. This eventually makes the organ to damage. It mainly occurs in people who are already ill and who have injuries. Symptoms such as shortness of breath and gasping for air, which usually occurs within an hour after an injury or infection.
History of Acute Respiratory Distress Syndrome
The Acute respiratory distress syndrome was first described in 1967 by Ashbaugh et al. Initially there was no clearly established definition, which resulted in controversy regarding the incidence and death of ARDS.
In 1988, an expanded definition was proposed, which quantified physiologic respiratory impairment.
Epidemiology
The main examination to utilize the 1994 AECC definitions was performed in Scandinavia, which announced yearly rates of 17.9 cases for every 100,000 population for ALI and 13.5 cases for each 100,000 populace for ARDS.
Age-related differences in occurrence
ARDS may happen in individuals of all ages. Its rate increments with propelling age, going from 16 cases for each 100,000 men a very long time in those matured 15-19 years to 306 cases for every 100,000 man a very long time in those between the ages of 75 and 84 years. The age dispersion mirrors the occurrence of the hidden causes.
Sex-related contrasts in rate
For ARDS related to sepsis and most different causes, no distinctions in the rate amongst guys and females seem to exist. In any case, in injured patients just, the rate of the sickness might be marginally higher among females.
Risk factors of Acute Respiratory Distress Syndrome
Risk factors for ARDS include:
Risk factors due direct conditions such as
- History of alcoholism
- Chronic lung disease
- Over 65 age-old
- Smoking
- Ventilators
Risk factors for indirect conditions such as
- Liver failure
- Drug reactions
- Fat metabolism in the lungs may block arteries
- Pancreatitis
Causes
It is caused by damage to the blood vessels in the lungs and leads to leakage of fluid from these vessels into the air sac in the lungs. When these air sacs are filled with fluid, less oxygen is supplied to the bloodstream.
Some of the common condition or causes of acute respiratory distress syndrome are as follows:
Sepsis: It is caused by bacterial infection in the bloodstream.
Pneumonia: Severe cases of pneumonia will affect all five lobes of the lungs.
Inhalation of harmful substances: Inhaling harmful smokes or chemical fumes and vomit.
Head, chest or other major injuries: Injury due to harsh accidents or falls may damage the lungs or part of the brain that manipulates breaths.
Overdosing on sedatives or tricyclic antidepressants
Difference between normal and ARDS alveoli
Manifestation of ARDS
When ARDS affects the patient, they feel severe difficulties while breathing, which can be indicated by various symptoms. Signs of ARDS include:
- Painful breathing
- Rapid breathing
- Accelerated pulse rate
- Exasperated cough
- Adequate fever
- Severe shortness of breath
- Mental Confusion or drowsiness
- Severe headache
- Low blood pressure
- Plenty of sweating
- Less oxygen content in the blood
- Extreme weakness and muscle fatigue
- Blue colored lips and nails due to lack of oxygen
- Frequent dizziness and fainting
- Feeling anxiety and exhausted
Complications of Acute Respiratory Distress Syndrome
- Pneumothorax or collapsed lungs – Air or gas collects in the space between the lungs cause collapse of two lungs. Pressure applied from a ventilator can cause this condition.
- Pulmonary fibrosis – Lungs become hard and stiff, thereby difficult to breathe. The prolonged period under ventilator can cause this lung scarring.
- Post-traumatic stress disorder – Psychological disorder during the course of the disorder.
- Pulmonary embolism – Blood clot during ARDS is due to utilization of ventilator. The clot develops in the veins and a portion of it travels into the lungs and stops blood flow.
- Infections – Being on a ventilator for a long duration in the hospital can put a patient into infections such as pneumonia.
- Untreated infections may finally lead to death.
Diagnosis and Test
Various assessments on ARDS likely include:
- Blood test – Amount of oxygen in the blood and infection in the blood is analyzed through a blood test.
- Pulse oximetry test – A pulse oximeter is a sensor device used to measure the oxygen saturation level in the blood.
- Arterial blood gas test – It involves radial artery puncture using a needle, and blood is aspirated to measure the oxygen level in the blood. This reveals the presence of hypoxemia.
- Complete blood count – Used to check the number of WBC’s during sepsis.
- Chest X-Ray – X-Ray along with the CT- scan can reveal the amount of fluid surrounded in the lungs and also checks the condition of the heart.
- Sputum culture – In this test a spit while coughing out from the lungs is taken to find the cause of infections.
- Throat and nose swab – To find the causative agent swabbing of the throat and nose is done.
- Bronchoscopy – A procedure used to visualize the windpipe and airways of the lungs for the evaluation of the degree of infection.
Heart test
Since the signs and symptoms of ARDS are similar to heart problems doctors may recommend to do the following tests:
Electrocardiogram: It involves the tracking of electrical activity if the heart.
Echocardiogram: It measures the sonogram of heart, and shows its functional and structural problems
Treatment that involved in ARDS
If the patient is suspected to have ARDS, he/she should be admitted to the Intensive Care Unit (ICU). The main aim of treating ARDS is to get back the normal levels of oxygen into the organs and to evacuate the infectious agent from the lungs and airways. Assistive devices are accompanied to help the breathing problems.
Oxygen therapy`
To get a sufficient oxygen supply to the organs, it is advised to use the following:
Supplementation of oxygen: For very mild cases of ARDS, oxygen is delivered through a mask which is connected to a machine. The mask is attached to the mouth very closely without any gap. The machine that is attached to a mask allows setting a limit of oxygen flow into the patient respiratory airways.
Mechanical ventilator: In severe cases of ARDS needs mechanical ventilators. It is a machine having two-way breathing tubes that is inserted into the pathways of the lungs. Through the first tube, it pushes the air from the machine into the lungs and the second tube collects the excess fluids from out of the air sacs. To place the breathing tube your doctor may perform a tracheotomy. Patients with ARDS need to spend about 16 days in ICU and totally 26 days in a hospital.
Extracorporeal membrane oxygenation (ECMO)
For severe cases of ARDS, the mortality rate is high. To reduce the risk of mortality rate in patient ECMO can be used as a final chance for the life-saving purpose. In this treatment, a pump is used to circulate the blood back into the bloodstream through an artificial lung.
Positive End-Expiratory Pressure (PEEP)
The doctor helps a patient to breathe through a technique known as Positive End-Expiratory Pressure (PEEP). It is a technique to control the pressure developed surrounding the lungs and helps to decrease the lung injury from using a ventilator. Thus, lung functions can be increased.
Medications
Medications are usually given to reduce the suffocation from forceful breathing, blood clots in the lungs, gastric reflux, and infection and to sedate.
- Antibiotics to reduce the infections such as pneumonia and sepsis
- Pain relief medications to reduce the discomfort
- Anticoagulants can be used to reduce the blood clot
- Sedatives to make the patient rest
Pulmonary Rehabilitation
Medical centers offer many rehabilitation programs for ARDS patient to recover. Training such as meditation, yoga, and breathing exercises are given to make the patient’s lungs fit. Lifestyle classes and support teams are there to help the patient from ARDS.
Prevention of Acute Respiratory Distress Syndrome
Home remedies and lifestyle changes
- Quit smoking – smoking may affect the surfactants in the lungs. Thus, it is best to avoid smoking.
- Vaccination – Getting pneumonia vaccination properly will reduce the chances of getting ARDS.
- Ongoing frequent monitoring of lungs and heart functions.
- Lying down for long periods cause blood clots. So it is advised to be active in the day time to counter the development of blood clots.
- Proper nutrition, which consists of enough fluid may improve the blood flow to the lungs and other parts of the body.
- Avoid alcohol.
- Regular physical exercise and physical therapy increase and strengthen the lung capacity and its function.
- Try to control the feelings emotionally such as stress, anxiety, and depression.
- Seek professional help if you have symptoms such as difficulty breathing, stress, and loss of interest in doing regular activities.