ARDS

Question 1

ARDS

Answer 1

severe inflammation of the lung results in an inefficient supply of oxygen to the body.

caused by a serious underlying health condition (e.g. already in hospital / influenza / pneumonia / aspiration)

other causes: cardiopulmonary bypass, pulmonary contusion, smoke inhalation, pneumonia, near drowning, aspiration of gastric contents. sepsis, burns, DIC, pancreatitis, drug OD, trauma.

Question 2

ARDS symptoms

Answer 2

• acute onset (within 1 week)
• arterial hypoxaemia
• bilateral fluffy pulmonary infiltrates on CXR not explained by effusion/nodules/collapse
• non-cardiogenic pulmonary oedema (pulmonary capillary wedge pressure <18cmH2O)
• reduced lung compliance

severe SOB
raised RR
shallow breathing
drowsy
confused
light headed

(ddx panic attack, DKA, asthma attack, CO poisoning)

Question 3

ARDS pathophysiology

Answer 3

damage to the capillary endothelium and alveolar epithelium- increased capillary permeability. results in accumulation of protein rich fluid in the alveoli. causes diffuse alveolar damage.
activation of neutrophils causes further damage.

leaking of fluid in to the alveolar sacs of the lungs

O2 is inhaled into the alveolar and should diffuse into the blood. in ARDS, fluid fills the air sac and the integrity is compromised = alveolar collapses (atelectasis) which compromises gas exchange

lung shrinks on CXR

Question 4

ARDS investigation

Answer 4

blood including septic screen, cultures
blood gass
pulse oximetry
CXR
echo
urine culture

Question 5

ARDS management

Answer 5

non-pharmacological
(guided by the severity of hypoxaemia)

ICU
supplemental oxygen
PEEP
mechanical ventilation

IV hydration
nutritional support
VTE prophylaxis

sepsis tx
NO
corticostoeirds