Acute respiratory distress syndrome [ARDS]

Causes and risk factors

Inspired air travels through nose, trachea, lungs and ultimately reaches air sacs i.e. alveoli of the lungs. Here gaseous exchange takes place in the alveolar capillaries. Oxygen is taken up by the blood stream and is transported further to different organs and tissues. Some conditions cause fluid to build up in the alveolar sacs disrupting the transport of oxygen to the blood stream. This leads to respiratory distress. Common risk factors for ARDS include sepsis, pneumonia, aspiration of gastric contents, aspiration into the lungs in neonates, unconscious patients, and children, burns, shock, infection, lung contusion, nonthoracic trauma, toxic inhalation, near-drowning, drug overdose and multiple blood transfusions.

Clinical presentation

ARDS is marked by the rapid onset of profound dyspnoea that usually occurs 12–48 hours after the initiating event. Shortness of breath, Laboured breathing, tachypnea is observed. There is low blood pressure. Patient complains of extreme tiredness, confusion due to low oxygen level in blood. Intercostal retractions are seen.

Investigation

Medical history by the patient and Clinical examination by the doctor helps in diagnosis. Auscultation of chest will reveal lung abnormality such as crackles are noted. Imaging studies such as Chest x-ray, CT scan of chest is useful for further evaluation. Arterial blood gas test to measure oxygen level is recommended. Electrocardiogram to measure electrical activity of the heart may be advised.

Treatment

ARDS is an emergency condition and hospitalization is needed. The aim of treatment is to improve oxygen levels and promote lung healing. Supplemental oxygen therapy or mechanical ventilation is necessary. Fluid management to prevent fluid build up in the lungs is needed. Treatment of any underlying cause is done, such as antibiotics in case there is bacterial infection like pneumonia. Appropriate use of sedatives, analgesics, and antipyretics is done. Medications like blood thinners and use of compression stockings to prevent blood clots contribute further to the treatment. Supportive care is given such as nutrition through feeding tube is required.