Acute respiratory distress syndrome (ARDS) is a life-threatening lung condition in which there is insufficient oxygen in the lungs and in the blood. ARDS results from several serious conditions. Shortness of breath and a blue skin color are some typical symptoms of ARDS. The treatment consists of medication and respiratory support. In addition, it is necessary to treat the underlying cause of Acute Respiratory Distress Syndrome. The prospects are generally not good. One of the most famous people said to have suffered from ARDS is the British pop singer George Michael, who died at the age of 53 on December 25, 2016.
- Synonyms Acute Respiratory Distress Syndrome
- Epidemiology ARDS
- Causes: Damage to the lungs
- Risk factors: insufficient oxygen in lungs and blood
- Symptoms: Shortness of breath
- Diagnosis and examinations
- Treatment: Ventilation and medication
- Complications
- Prognosis for lung disease is poor
Synonyms Acute Respiratory Distress Syndrome
Acute Respiratory Distress Syndrome (ARDS) is also known by these synonyms:
- acute lung injury
- pulmonary edema, increased permeability
- non-cardiogenic pulmonary edema
- shock lung
Epidemiology ARDS
The incidence increases with age, ranging from 16 cases per 100,000 persons in patients aged 15-19 years and 306 cases per 100,000 persons in patients aged 75 to 84 years. The age distribution reflects the influence of the underlying causes. The gender predilection depends on the cause. Women are slightly more likely than men to be affected when the cause of ARDS is due to trauma. No clear sexual predilection has been reported for most other causes.
Causes: Damage to the lungs
ARDS is due to strong direct or indirect damage to the lungs. This causes tissue damage, causing the release of chemicals that spread through the blood and damage the lungs (and other tissues). Common causes include:
- acute pancreatitis inflammation of the pancreas with abdominal pain and digestive problems
- a near-drowning
- pneumonia (pneumonia: inflammation of the lower respiratory tract)
- a lung transplant
- a negative reaction to a blood transfusion
- septic shock (complication of sepsis with low blood pressure)
- a trauma such as a serious brain injury or chest injury
- the use of certain cancer medicines
- breathing in vomit that goes into the lungs (aspiration pneumonia)
- inhaling chemicals/toxic fumes
ARDS leads to a build-up of fluid in the alveoli. This means that insufficient oxygen enters the bloodstream. The fluid accumulation also makes the lungs heavy and stiff, because the alveoli are less elastic. This reduces the expansion capacity of the lungs. The oxygen level in the blood often remains dangerously low even if the patient receives oxygen through a breathing machine (ventilator) through a breathing tube (endot racheal tube). Shortness of breath and breathing problems are therefore the main symptoms of this disease. Respiratory support and medications treat this disease, which has a variable prognosis.
Risk factors: insufficient oxygen in lungs and blood
ARDS is often accompanied by failure of other organ systems, such as the liver (liver failure) or kidneys (renal failure (reduced or absent kidney function)). Sepsis (blood poisoning: exaggerated response of the immune system to germs) is a risk factor. Cigarette smoking and excessive alcohol consumption are other risk factors.
Symptoms: Shortness of breath
Symptoms develop in most patients within 12 to 48 hours after the injury or disease. Patients with ARDS are often seriously ill. Breathing problems, shortness of breath (dyspnea), rapid breathing, low blood pressure, coughing and organ failure are common symptoms of Acute Respiratory Distress Syndrome. The patient also has a blue discolouration of the skin and mucous membranes (lips and nails) due to an oxygen deficiency in the tissues. This blue coloration is known medically as “cyanosis”. Finally, fatigue, drowsiness and confusion are other characteristics of the disease.
Diagnosis and examinations
Physical examination
The doctor asks the patient about the patient’s medical history and current symptoms. He then listens through a stethoscope (auscultation) to the breathing sounds that are abnormal in ARDS. These cracking sounds (rattles) indicate the presence of fluid in the lungs. The blood pressure is often also low (hypotension). Cyanosis is also common.Electrocardiography (ECG) / Source: CardioNetworks, Wikimedia Commons (CC BY-SA-3.0)Diagnostic examination The following diagnostic examinations are necessary to diagnose Acute Respiratory Distress Syndrome:
- a blood test (a low oxygen level in the blood is present in ARDS)
- a bronchoscopy (internal examination of the airways; not done in all patients)
- a CT scan of the chest/heart and lungs; this reveals pulmonary edema (fluid in the lungs due to left heart failure)
- an echocardiography to rule out heart disease (the results are comparable to those of ARDS via a chest x-ray).
- an electrocardiography (ECG: measurement of the electrical activity of the heart )
- a pulse oximetry for measuring the oxygen level in the blood
- a sputum culture and sputum analysis
- a chest x-ray: X-ray of the chest (chest x-ray) showing significant tissue damage to the lungs
- a urine test
Differential diagnosis
Other conditions that the doctor takes into account once he has identified the patient’s range of symptoms include the following conditions:
- acute eosinophilic pneumonia
- acute hypersensitivity pneumonitis (pneumonia due to inhalation of substances)
- respiratory failure
- aspiration pneumonia
- bacterial sepsis
- ventilator associated pneumonia
- a near-drowning
- a side effect to medication
- a hemorrhagic shock
- a pulmonary hemorrhage
- a pneumonia
- a septic shock
- heroin toxicity
- Goodpasture syndrome (autoimmune disorder with symptoms in the kidneys and lungs)
- the Hamman-Rich syndrome
- the retinoic acid syndrome
- toxic shock syndrome (severe bacterial infection with fever and organ damage)
- the tumor lysis syndrome
- the fatty embolism syndrome
- leukemic infiltration
- mechanical ventilation
- non-cardiogenic pulmonary edema
- non-invasive ventilation
- pulmonary eosinophilia
- reperfusion damage
- salicylate toxicity
- sepsis
- transfusion-related acute lung injury
- transfusion reactions
- hospital-acquired pneumonia (nosocomial pneumonia: form of a hospital infection)
Medicines fight the infection / Source: Stevepb, Pixabay
Treatment: Ventilation and medication
The treatment of ARDS is usually done in the hospital intensive care unit. The doctor wants to support breathing and treat the cause of ARDS. For example, he uses medicines to fight infections and removes fluid from the lungs. The patient is often ventilated via a breathing machine, which provides high doses of oxygen and positive pressure. The oxygen enters the body through a mask but usually through a tube in the trachea while the patient is anesthetized. The doctor also treats any other affected organs. The damage to this is due to the inflammation-inducing substances produced in the lungs as a result of the injury. The doctor will do everything he can to protect the lungs against further damage. The treatment is mainly supportive until the lungs recover.
Complications
Problems arising from Acute Respiratory Distress Syndrome or its treatment include:
- ventilator-associated pneumonia
- pulmonary emobilia due to the development of blood clots
- memory problems and cognitive disorders
- the failure of many organ systems
- pulmonary fibrosis (scarring of lungs with shortness of breath)
- lung damage, such as a collapsed lung (pneumothorax) due to injury from the required ventilation during the treatment process
Some patients also develop psychological problems, such as post-traumatic stress disorder (PTSD: a type of anxiety disorder, in which an extreme emotional reaction occurs to a scary event ) and depression.
Prognosis of lung disease is poor
About one third of patients with ARDS die from the disease. Patients who survive regain most of their normal lung function, but many patients still have permanent (mild) lung damage because scar tissue has formed in the lungs. Surviving patients suffer from memory loss or other disabilities. This is the result of brain damage that the patient suffered during the malfunction of the lungs and brain because they did not receive enough oxygen.