Summary
There is a wide range of respiratory ailments and conditions that affect humans, worldwide. One of them is Acute Respiratory Distress Syndrome or ARDS. ARDS can have life-threatening consequences if not treated on time, or treated effectively. It also has long-term effects on the patient. Given its serious nature, ARDS is treated on an emergency basis. However, over the years, treatment options have improved, so, today, ARDS patients can look forward to complete cure and better quality of life thereafter. In this article, we will learn more.
Introduction
Most of us know how the respiratory system functions. Air that we inhale moves through the wind-pipe or trachea to reach both the lungs. The lungs are made up of lobes filled with air-sacs or alveoli. Thousands of alveoli inside the lungs facilitate gas exchange. That is, oxygen from the inhaled air is absorbed by the blood-vessels in these alveoli, and this oxygenated blood is transported to the heart and thereafter to rest of the body. Carbon-di-oxide from previously inhaled and processed air is expelled from the alveoli, out of the lungs and out of the body, through exhalation.
Needless to say, the lungs are ‘dry chambers’ and must be kept dry always, for proper functioning. Else, it can be dangerous to the person. Solids and fluids that enter the lungs accidentally, if not removed quickly, can cause temporary, or long-term damage. ARDS is a condition which happens exactly this way. (Incidentally, toxic gases that are inhaled also cause damage, but they cannot be removed).
What is ARDS?
Acute Respiratory Distress Syndrome is a condition in which fluid (blood) starts filling up in the lungs. This happens when blood flowing in tiny capillaries in the lungs develop a leak. Normally, there is a thin membrane that encloses the capillaries. However, injuries and various conditions can cause the membrane to rupture, and the blood from capillaries to leak into the open space in the lungs (between the capillaries and alveoli). This increases the pressure in the lungs as some of the air is replaced by fluid now.
Gradually, the fluid enters the alveoli. This means the alveoli are no longer able to fully hold air, as they are now partly filled with fluid. This in turn means, gas exchange cannot happen properly. As a result, there is less oxygen being sent out from the blood in the lungs, to the rest of the body. The condition is called hypoxia (‘less oxygen’) which has life-threatening consequences. The different organs and parts of the body are no longer getting enough oxygen now which leads to damage and death to those tissues.
Causes and Risk Factors
- Sepsis: This is a widespread infection of the bloodstream which can be quite serious. It is the most common cause of ARDS. A person admitted in the hospital for sepsis treatment is at a high probability of developing ARDS.
- Inhaling harmful substances: Inhaling fumes containing toxic chemicals (as in industrial workers or severe air pollution from vehicle exhaust), breathing smoke from burning material, and long-term cigarette smoking are all risk-factors for ARDS.
- Aspiration pneumonia: When one inhales their vomit, or a lot of water from near-drowning episodes, they are at severe risk of ARDS.
- Severe pneumonia: Severe cases of pneumonia can affect all the lobes of the lungs and eventually trigger ARDS.
- So also, patients of Chronic lung disease are at high risk of developing ARDS.
- Major trauma or burns: Accidents (like vehicle crashes), falls from heights and collisions (as in contact sports) may directly damage the head, chest, lungs or parts of the brain that control breathing. This triggers severe inflammation in the lungs, and eventually ARDS.
- Coronavirus disease 2019 (COVID-19): People who suffer from severe COVID-19 are at risk of developing ARDS.
- Pancreatitis: This is an inflammation of the pancreas which eventually triggers ARDS.
- Massive blood transfusions: Accident victims and patients who require a lot of blood (receiving over 15 units of blood in a short period of time) are at high risk of ARDS.
- Drug overdose: Excessive use of drugs such as cocaine, opioids (sedatives) and tricyclic antidepressants increases risk.
- Alcoholism: People with a history of chronic alcoholism are at high risk of developing ARDS and dying from the same.
- Age: Being over 65 years of age
- Taking supplementary oxygen for some lung condition
- A recent high-risk surgery, or recent chemotherapy sessions
- Obesity
- Genetic factors: unknown gene mutations that cause such conditions
5 Signs and Symptoms
Breathing related
Circulation related
Metabolism related
- Low blood pressure
- Muscle fatigue and general weakness
Visible signs
- Bluish colour of fingernails, skin and lips due to low oxygen levels in blood
Others
- Confusion and extreme tiredness
- Dry, hacking cough
- Fever
- Headaches
- Dizziness
Complications from ARDS
- Blood clots: Hospitalization can cause long hours of lying down while being hooked to a ventilator which increases the risk of blood-clots in deep veins of the legs. Some of these clots can break off and move to the lungs where they block blood-flow, thereby worsening the symptoms of ARDS.
- Collapsed lung or pneumothorax: ARDS will require the use of ventilator to increase oxygen levels in the body and also force fluid out of the lungs. However, the high-air pressure from the ventilator can cause a small hole to develop on the outside of the lung. Air inside the affected lung starts leaking out of this hole, and eventually that lung collapses.
- Infections: The ventilator is attached directly to a tube that goes into the trachea. This being a foreign body increases the risk of infections from germs, and hence further injury to the lungs.
- Scarring or pulmonary fibrosis: Within a few weeks of ARDS developing, the tissue between the alveoli develops scarring and becomes thick. This makes the lungs stiff and inelastic. They can’t move smoothly like before, which makes it difficult for the oxygenated blood to flow from the alveoli into the bloodstream.
- Breathing trouble: Most people with ARDS are able to breathe normally within 6 months to 2 years’ time. Some will require supplemental oxygen to be given at home for a few months. While the remaining small percentage of patients may suffer from shortness-of-breath and fatigue, for the rest of their lives.
- Depression: Most ARDS patients suffer from depression both during and after treatment. However, this is not serious and is easily treatable.
- Cognitive issues: The low oxygen levels caused by ARDS and the sedatives used during treatment can cause memory loss and problems with clear thinking. This is a temporary situation with most of the patients. But in a small number of people, the damage is permanent. They will have to constantly work on their mind (problem solving puzzles, and staying mentally active) to overcome the situation.
- Muscle and overall fatigue: Lying on a hospital hooked to a ventilator for so long can cause atrophy of the muscles. They begin to weaken, so the person feels constantly tired after treatment. The person has to begin an exercise program to strengthen the muscles again.
Diagnosis
- Imaging tests such as chest X-ray and CT-scan
- Blood tests that look for signs of infection or anaemia, and measure oxygen levels in the blood
- Heart tests such as Electrocardiogram and Echocardiogram
- Pulse oximetry (a fingertip sensor) to constantly monitor oxygen levels
- Taking a sample of secretions from the patient’s airways (through throat and nose swabs) to find the cause of infection
- Physical examination of the airways
Treatment
- Supplemental oxygen for people with milder symptoms
- Mechanical ventilation to help the person breathe better (by forcing oxygen from air into lungs and forcing the fluid out of the air-sacs)
- IV Fluids that are carefully dispensed, to provide nutrition and medication
- Medication that helps to minimize fluid build-up in the lungs, to treat infection, prevent blood-clots in the legs and lungs, to sedate the person, to relieve pain and discomfort and to minimize or prevent gastric reflux.
- Diuretics to remove extra fluid in body due to ARDS
- Lifestyle changes: quitting smoking, minimizing alcohol consumption and taking regular vaccine shots for flu and pneumonia
- Physical therapy to recover muscle strength
- Pulmonary rehabilitation to strengthen the lungs and improve breathing by increasing lung capacity
Kauvery Hospital is globally known for its multidisciplinary services at all its Centers of Excellence, and for its comprehensive, Avant-Grade technology, especially in diagnostics and remedial care in heart diseases, transplantation, vascular and neurosciences medicine. Located in the heart of Trichy (Tennur, Royal Road and Alexandria Road (Cantonment), Chennai (Alwarpet & Vadapalani), Hosur, Salem, Tirunelveli and Bengaluru, the hospital also renders adult and pediatric trauma care.
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