Generality
ARDS is a rather serious medical condition, characterized by an inflammatory process on the lungs, which compromises the functionality of the alveoli and their ability to assimilate oxygen from the inhaled air.
The diagnosis of ARDS is based on several tests, including: physical examination, medical history, chest X-ray, chest CT, etc.
The treatment includes: hospitalization in intensive care, oxygen infusion through oxygen therapy and mechanical ventilation, artificial nutrition and a series of pharmacological treatments aimed at avoiding some possible ARDS complications.
What is ARDS?
ARDS, or respiratory distress syndrome, is a serious medical condition, characterized by inflammation of the lungs and the consequent inability of the lungs to assimilate the oxygen required within the body.
In other words, those suffering from ARDS have inflammation of the lungs, so that they are unable to retain the quantity of oxygen necessary for good health and proper functioning of the organs and tissues from the inhaled air. of the body.
Epidemiology
According to some statistical surveys, the ARDS would have an incidence, on the general population, of 13-23 cases per 100, 000 people.
Causes
The most common causes of ARDS are:
- Sepsis . It is a potentially lethal complication of a bacterial infection, which induced an exaggerated systematic inflammatory response.
Sepsis is the most common cause of ARDS;
- Inhalation of substances harmful to human health . For example, it can cause ARDS to breathe high concentrations of cigarette smoke or fumes from toxic chemicals;
- Accidental inhalation of vomit ;
- Severe pneumonia ;
- Serious influence ;
- Strong trauma to the chest ;
- Acute pancreatitis . Pancreatitis is inflammation of the pancreas. Pancreatitis is called acute, when it is established suddenly, due to an equally sudden event;
- Adverse reactions to multiple blood transfusions ;
- Severe burns .
PATHOPHYSIOLOGY
Premise: inside the lungs, at the end of the respiratory tract, small characteristic pockets take place, surrounded by a dense network of blood vessels, whose specific name is pulmonary alveoli or simply alveoli .
Enclosed by a thin wall with elastic properties, the pulmonary alveoli represent the site that collects the inhaled air rich in oxygen and in which the assimilation of the latter takes place, by the blood circulating within the neighboring vascular network.
When drawing oxygen, the blood circulating around the alveoli releases carbon dioxide (a waste product of human metabolism).
Therefore, the vital gas-carbon dioxide exchange takes place in the pulmonary alveoli, which culminates in the oxygenation of the blood and the expiration of air rich in carbon dioxide.
Returning to the subject of the article in question, in ARDS the inflammation of the lungs affects the thin elastic wall of the pulmonary alveoli, compromising its integrity.
The absence of an intact alveolar wall causes the blood circulating within the neighboring vascular network to penetrate into the pulmonary alveoli, effectively occupying the space reserved for oxygen-rich air, coming from inspiration.
The invasion of the interior of the alveoli by the blood alters the functionality of the alveoli, which are no longer able to properly inject air from the outside. From this, it follows that the blood oxygenation process is insufficient to meet the needs of the entire body.
Symptoms, signs and complications
The typical ARDS symptoms are:
- Dyspnea (or shortness of breath);
- Abnormal increase in respiratory rate;
- Hypotension;
- Confusional state;
- Fatigue and drowsiness;
- Tendency to fainting.
The intensity of these clinical manifestations varies in relation to the severity of the triggering cause: the more serious a cause, the more marked and evident the symptomatic picture.
WHEN DO THE SYMPTOMS APPEAR?
In most cases, the ARDS symptoms are established after 1-2 hours from the causal causative event; more rarely, they appear after 1-3 days.
WHEN TO REFER TO THE DOCTOR?
The ARDS represents a medical emergency, therefore those who suffer from it need immediate care, preferably at a hospital (as it is equipped for such events).
COMPLICATIONS
In the absence of treatment and sometimes even during treatment, ARDS can give rise to various complications, some of which have a fatal outcome.
The possible complications of ARDS include:
- Pulmonary fibrosis;
- Pulmonary embolism;
- Pneumonia associated with mechanical ventilation (NB: mechanical ventilation is a medical support for spontaneous breathing);
- barotrauma;
- pneumothorax;
- Memory problems, cognitive problems and / or behavioral problems;
- Acute renal failure;
- Cardiac arrhythmias;
- Myocardial dysfunction;
- Gastrointestinal ulcers;
- pneumoperitoneum;
- Gastrointestinal dysmotility;
- Malnutrition.
Diagnosis
Currently, there is still no specific diagnostic test for the identification of ARDS. Therefore, to accurately diagnose respiratory distress syndrome, doctors use different tests, some of which are also aimed at the exclusion of pathologies with similar symptoms ( differential diagnosis ).
The tests for the diagnosis of ARDS include:
- An in-depth objective examination and, subsequently, a careful medical history . They allow to delineate the precise symptom picture and to get an idea of the probable causes.
- Oximetry . It is the test to measure the saturation of oxygen in the blood. Easy and quick to perform, it involves the use of an instrument called an oximeter.
- Blood tests . They allow to identify any infectious agents in the blood. Doctors use it to understand if the current condition may or may not be linked to an infection.
- A chest X-ray and / or a CT scan of the chest . They provide X-ray images of the lungs, images from which it is possible to identify any signs of ARDS.
- An electrocardiogram and / or an echocardiogram . They are used for differential diagnosis, to exclude whether or not current symptoms are due to heart disease.
Figure: X-ray vision of a subject's lungs with ARDS. Image taken from wikipedia.org
Therapy
ARDS treatment includes: hospitalization in intensive care, the use of therapies for raising oxygen levels in the patient's blood, adequate causal therapy, artificial nutrition and, finally, appropriate drug therapy .
Once the critical phase is over, ARDS also requires the adoption of a lifestyle that preserves the lungs and the organism in general from relapses.
What is intensive care?
Intensive care, or intensive care unit, is the hospital ward reserved for the hospitalization of patients in serious health conditions, who need continuous treatment, monitoring and support, in order to maintain their vital functions normally.
THERAPIES FOR THE RAISING OF LEVELS OF OXYGEN SANGUIGNO
To increase the blood oxygen levels of patients with ARDS, doctors resort to oxygen therapy and the aforementioned mechanical ventilation .
Oxygen therapy is the administration of oxygen through special medical instruments.
CAUSAL THERAPY
By causal therapy, in medicine we mean the treatment of the causes that trigger a specific morbid condition, in the hope of eliminating at the root what triggers the symptoms.
An example of ARDS causal therapy is antibiotic treatment, when at the origin of the condition there is a bacterial infection (eg, bacterial pneumonia).
ARTIFICIAL NUTRITION
In the case of ARDS, the use of artificial nutrition is essential, because patients are generally unable to feed themselves independently.
Without artificial nutrition, the patient runs the risk of running into a state of malnutrition.
PHARMACOLOGICAL THERAPY
Targeted more than anything to the prevention of complications, drug therapy for ARDS cases may include:
- Antibiotics, to prevent infections due, for example, to mechanical ventilation. In these situations there is also talk of antibiotic prophylaxis ;
- Painkillers and sedatives . The doctors give them to all those patients who report pain;
- Anticoagulants and antiplatelet agents, to prevent the formation of dangerous blood clots;
- Drugs to reduce gastric reflux . In ARDS patients, gastric reflux can be a consequence of the long period of immobility to which they are forced.
RECOMMENDED LIFESTYLE
In the case of ARDS, an adequate lifestyle strictly excludes cigarette smoking and alcohol intake.
Prognosis
Without timely and adequate care, ARDS has very high chances of being fatal; with the appropriate treatments, the aforementioned probabilities diminish, but the condition in question remains serious and deserves careful treatment.
Therefore, in the presence of ARDS, the prognosis can be defined as negative.
MORTALITY RATE
ARDS has a mortality rate of between 20 and 50%; similar percentages are to be considered high.
According to some studies, the factors that favor ARDS mortality are: the extreme gravity of the triggering causes, advanced age and a poor state of health.
