ARDS Flashcards
what is ARDS
acute respiratory distress syndrome
def
a non-cardiogenic pulmonary oedema and diffuse lung inflammation which complications serious illness
what is non-cardiogenic pulmonary oedema
pulmonary oedema cause by factors OTHER THAN raised pulmonary capillary pressure
what causes non-cardiogenic pulmonary oedema
changes in permeability of pulmonary capillary membrane
what is the aetiology of cardiogenic and non-cardiogenic pulmonary oedema
cardiogenic - increased pulmonary capillary pressure
non-cardiogenic - increased pulmonary capillary permeability
what is the criteria for ARDS
1 acute onset (one week)
2 bilateral opacities on CXR
3 PaO2/FiO2 (inspired oxygen) ratio of <300 on PEEP or CPAP >5cm H2)
what is the mortality rate with ARDS
40%
what are risk factors for ARDS
3S
severe illness
smoking
strong drink (alcohol)
what is the most common cause of ARDS
sepsis from pulmonary source
what is the second most common cause of ARDS
sepsis from non-pulmonary source
what are less common causes of ARDS
aspiration
acute pancreatitis
pathophysiology
alveolar damage causes alveoli to be filled with proteinaceous oedema fluid and inflammation
what clears ARDS spontaneously
active transport of Na and Cl across alveolar epithelium
what defines mild ARDS
300>PaO2/FiO2>200
what defines moderate ARDS
200>PaO2/FiO2>100
