Pulmonary edema

Question 1

Starlings equation.

Answer 1

QE=Kf[(Pmv-Pis)-sigma(PImv-PIis)]

Question 2

what types of things contribute to QE by way of the hydrostatic gradient

Answer 2

CHF, ARDS, hanging, thoracentesis

Question 3

what types of things contribute to QE by way of oncotic gradient?

Answer 3

hypoalbuminemia (liver failure, nephrotic syndrome, malnutrition)

Question 4

what is the major determinant of edema clearance from alveoli?

Answer 4

Apical Na/K and Cl channels and Basolateral Na/K-ATPase

Question 5

what are some characteristics of ARDS?

Answer 5

Develops after an at-risk condition (sepsis, aspiration, trauma, etc), diffuse alveolar damage, refractory hypoxemia, high mortality, bilateral infiltrates in absence of LA htn

Question 6

define ALI, moderate ARDS, severe ARDS

Answer 6

P/F <100

Question 7

Four main mechanisms of injury in ARDS

Answer 7

Inflammation leading to endothelial and epithelia cells. Increased permeability. Influx of protein-rich edema and inflam cels into airspaces. Surfactant dysfxn (alveolar collapse)

Question 8

Three other mechanisms of injury in ARDS

Answer 8

Coagulation abnormalities (platelet-fibrin thrombi). Ventilator induced lung injury (VILI). Fibrosis/aberrant repair

Question 9

How does sigma in Starlings equation change in ARDS

Answer 9

it approaches or equals zero, eliminating oncotic forces

Question 10

describe evolution of ARDS

Answer 10

90% develop ARDS w/in 72 hrs of at-risk diagnosis. Edematous stage-first two days. Exudative stage-days 2 to 7, hyaline membranes, DAD. Proliferative stage-7 to 10 days, Interstitial inflammation/fibrosis