Respiratory Failure and ARDS

Question 1

what is respiratory failure

Answer 1

inadequate gas exchange
hypoxemia
hypercapnia

Question 2

define hypoxic failure

Answer 2

failure of oxygenation

Question 3

define hypercarbic failure

Answer 3

failure to eliminate CO2

Question 4

symptoms at 90% O2 saturation

Answer 4

loss of night vision, high altitude pulmonary edema

Question 5

symptoms at 80-89% O2 saturation

Answer 5

poor judgement, impaired coordination, drowsiness

Question 6

symptoms at 70-79% O2 saturation

Answer 6

handwriting, speech, vision, memory, judgement, intellect, and pain sensation impairment

Question 7

symptoms at <69% O2 saturation

Answer 7

circulatory failure, CNS failure, convulsions, cardiovascular collapse, and death

Question 8

what is the alveolar-arterial gradient

Answer 8

difference between the alveolar PO2 and arterial PO2
should be less than 30
typically 1/2 to 1/3 of age

Question 9

what is the room PO2

Answer 9

160 mmHg

(760 mmHg x 21%) where 21% is the amount of )2 in the air

Question 10

what is the vocal cord PO2

Answer 10

150 mmHg- accounts for humidified air

(760mmHg - 47mmHg) x 21%

Question 11

radiographic differences between a patient with ARDS and CHF

Answer 11

usually normal heart size (as opposed to enlarged)

patchy or diffuse edema (as opposed to central)

Question 12

what is the normal PO2/FIO2 ratio?

Answer 12

90/0.21 = 429 mmHg

Question 13

what is a PO2/FIO2 ratio consistent with ARDS?

Answer 13

90/.3 = 300 mmHg is mild
90/1 = 90 mmHg is severe

Question 14

pathophysiology of ARDS

Answer 14

still not well understood
macrophages, neutrophils and protein enter the alveoli. Water follows
Anti-diuretics do not help

Question 15

what is the treatment for ARDS

Answer 15

none

can mechanically ventilate and hope they recover

Question 16

what is the difference between ARDS and CHF

Answer 16

ARDS is noncardiogenic pulmonary edema

Question 17

what is PEEP

Answer 17

positive end expiratory pressure

prevents ventilated patients from getting to a pressure that is equal to atmosphere

Question 18

DDx for ARDS

Answer 18

CHF
connective tissue disease
Goodpasture's
Alveolar hemorrhage
drug induced lung disease
Cancer
TB

Question 19

what is the timing of ARDS onset

Answer 19

within one week of clinical insult
or
new or worsening respiratory symptoms

Question 20

epi of ARDS

Answer 20

men > women
older patients (mean onset age 61)
comorbidity: COPD or diabetes is common

Question 21

risk factors of ARDS

Answer 21

direct lung injuries:
pneumonia
aspiration
pulmonary contusion
inhalation injury
drowning
Indirect lung injury:
sepsis
shock
pancreatitis
burns

Question 22

3 most common risk factors for ARDS

Answer 22

pneumonia
sepsis
aspiration

Question 23

mortality rate for ARDS

Answer 23

35%

Question 24

why is mortality rate for ARDS decreasing?

Answer 24

equipment works better, newer technology

still no cure or treatment for ARDS

Question 25

what volume of positive pressure should be used to treat ARDS?

Answer 25

low volumes
6mg/kg of ideal body weight
use PEEP

Question 26

is it recommended to treat with liberal or a conservative fluid management for ARDS?

Answer 26

conservative

Question 27

what is the pharmacologic treatment for ARDS?

Answer 27

unknown

nothing improves outcomes so far

Question 28

what can be done physically to improve ARDS?

Answer 28

place patient prone

Question 29

when do you use ECMO? (extra corporeal membrane oxygenation)

Answer 29

in severe cases, when nothing else is working
severe hypoxemia
acidemia
high inspiratory pressure

Question 30

contraindications of ECMO?

Answer 30

high pressure ventilation > 7 days
high FIO2 requirements
anticoagulation therapy

Question 31

what is the goal of ECMO

Answer 31

don’t do damage

buy time