ARDS- Acute Respiratory Distress Syndrome

Question 1

What is ARDS?

Answer 1

Non-cardiogenic pulmonary oedema and refactory hypoxaemia.

Question 2

Lung damage precipitates ARDS. Which 2 conditions result in lung damage

Answer 2

Pulmonary conditions

Extra-pulmonary conditions

Question 3

Give 4 examples of pulmonary conditions that lead to lung injury and ultimately the development of ARDS.

Answer 3

Lung infections; Pneumonia
Toxic gas inhalation
Aspiration of gastric content
Near drowning

Question 4

Give 6 examples of extra-pulmonary conditions that lead to lung injury and ultimately the development of ARDS.

Answer 4

Sepsis 
Acute Pancreatitis
Drugs 
Malaria
Multiple transfusions
Trauma and burns

Question 5

Explain how extra-pulmonary conditions lead to lung injury, which leads to ARDS

Answer 5

Neutrophils are accumulate in the lung tissue and are activated. These then release dangerous toxins which damage the lung tissue

Question 6

Name and explain 2 ways that diffuse lung injury can occur in ARDS.

Answer 6

Injury to the alveolar-capillary barrier which leads to increased pulmonary permeability - with leakage of fluid into the alveoli= pulmonary oedema.

Capillary/vascular endothelial injury. - Obstruction of pulmonary vascular bed.

Question 7

What changes can one expect to see when there is damage to the capillary-alveolar barrier and intra-vascular/endothelial injury?

Answer 7

Flooding of the alveoli with protein rich fluid.
Collapse of the alveoli
Severe hypoxaemia

Question 8

Give 3 clinical signs of ARDS in a patient

Answer 8

Acute onset of dyspnoea

Respiratory distress

Question 9

Briefy give a summary of how ARDS develops

Answer 9

Patient undergoes massive trauma or injury
Systemic injury precipitates the release of neutrophils in the body.
Neutrophils enter lung tissue of the patient and are activated
Activated neutrophils releases toxic substances within the Lungs
ARDS

Question 10

How is ARDS diagnosed?

Answer 10

High clinical suspicion
Blood-gas must be taken, indicating hypoxaemia
Diffuse alveolar damage; Bilateral pulmonary infiltrate

Question 11

NOTE:

Answer 11

High index of suspicion is needed during dx, anyone can develop ARDS if they have predisposing injuries.
Cardiac causes of pulmonary edema must be excluded
Time of the onset of ARDS may vary

Question 12

How is ARDS treated?

Answer 12

High concentration of O2
Mechanical ventilation in an ICU
Treat the underlying causes that precipitate ARDS i.e. sepsis.