ARDS.

Question 1

ARDS

Answer 1

syndrome, not a disease; caused by something.
characterized by diffuse lung injury and noncardiogenic pulmonary edema; caused by a severe, systemic inflammatory response in the lungs

Question 2

mortality

Answer 2

40-60%, 60-80% depending on the cause and complications; varies b/c initiating event, age

Question 3

caused by

Answer 3

any insult that causes the inflammatory response can cause ARDS, can be in the pulmonary system or systemic wide

Question 4

direct injury

Answer 4

aspiration, pulmonary infections, pulmonary contusions, toxic inhalation

Question 5

indirect injury

Answer 5

sepsis (#1), aspiration, shock, mult. trauma, drug OD (heroine), inhalatoin injuries, hyper-transfusion of blood, pancreatitis, cardiopulmonary bypass

Question 6

cascade

Answer 6

injury - inflammation - pmn leukocytes - endotoxin - increased cap membrane permeability, changes in small airway diameter, injury to pulmonary vasculature - alveolar flooding, increased resistance/decreased lung compliance, pulm vasoconstriction, micro emboli, pulm htn - alveolar collapse, increased work of breathing, alveolar dead space, increased RV after load - hypoxemia, decreased CO

Question 7

refractory hypoxemia

Answer 7

harder to ventilate

Question 8

alveoli are suddenly flooded

Answer 8

ventilation but no gas exchange

Question 9

s/s

Answer 9

acute onset (48hr); resp distress: increased RR, accessory muscles, working really hard to breathe; refractory hypoxemia: continue to get harder to oxygenate; bilateral diffuse pulmonary infiltrates: lungs look white.
normal wedge pressure: b/c there is no cardiac problem.

Question 10

decreased FRC and lung compliance

Answer 10

more and more pressure to deliver tv

Question 11

unresponsive to standard O2 therapy

Answer 11

interstitial edema

Question 12

appearance of lungs

Answer 12

heavy, congestive, hemorrhagic, boggy; not obstructive, just wet; alveolar walls thicken, edema; flood alveoli through permeability defect

Question 13

increased permeability

Answer 13

pulmonary edema and interstitial edema

Question 14

shunting and ventilation/perfusion mismatch R-L

Answer 14

perfusing fine, no gas exchange; unoxygenated blood through lungs to left heart

Question 15

ineffective srufactant activity

Answer 15

disrupts both synthesis and storage of surfactant leading to decreased lung compliance and atelectasis

Question 16

inreacsing pulmonary vascular resistance

Answer 16

vasoconstriction b/c hypoxic; fluid = increased pressure on pulmonary vessels, resistance to blood flow, micro emboli

Question 17

altered lung compliance

Answer 17

increased work of breathing, lungs less stretchy = decreased FRC b/ cog increased interstitial fluid and atelectasis

Question 18

reduction in lung volumes

Answer 18

due to stimulation of the inflammatory/immune system/pmn leukocyte activated and produces inflammation

Question 19

stages of ARDS:

Answer 19

early - subtle, within 1 week of onset, neutrophils sequestering, crackles, patchy opacities, very reversible.
fibroblast and inflammatory cells infiltrate lungs to fix it, but causes vascular remodeling; increased interstitial edema, multi-system involvement; hemodynamic involvement; hypoxemia harder to treat.
scarring in lungs, emphysematous type changes, 10 days - 3 weeks; multi system involvement.
ALWAYS BILATERAL

Question 20

A-a gradient

Answer 20

measure of hypoxemia in general, not ARDS
alveolar o2 vs arterial o2
alveolar - 104 mmhg, fluctuates <15
arterial - 95-100 mmhg
normal gradient is less than 15 mmhg; greater than = hypoxia

Question 21

management

Answer 21

treat the underlying cause of the inflammation; provide oxygenation, mechanical vent ,ABGs, use of sedation, hub >10, <12; fluid therapy, PA cath and hemodynamic monitoring; prevent infection - vent acquired pneumonia, loss of skin integrity from invasive devices; prone position - controversial

Question 22

inhaled nitric oxide

Answer 22

selective pulmonary vasodilator with no systemic effects

Question 23

corticosteriods

Answer 23

treat ARDS

Question 24

ECMO

Answer 24

helps with gas exchange

Question 25

healing

Answer 25

length of disease determines lifelong effects