ARF and ARDS

Question 1

normal blood gas levels: Pa O2 and PaCO2

Answer 1

O2: 80-100mmHg
CO2: 30-45 mmHg

Question 2

what is is called when lungs can’t perform adequate gas exchange?

Answer 2

respiratory failure

Question 3

intrinsic vs extrinsic resp failure

Answer 3

intrinsic: problems with the lungs themselves (obstructive and restrictive disorders, pulm. vasc disorders)
extrinsic: problems with external structures that effect the lungs (neuromuscular, pleural and chest wall disorders)

Question 4

what is it called when PaO2 is <50-60mmHg

normal should be around 100

Answer 4

acute respiratory failure

Question 5

two types of acute respiratory failure

Answer 5

acute hypoxemic respiratory failure - mostly intrinsic

acute hypoventilatory respiratory failure - mostly extrinsic

Question 6

acute hypoxemic resp. failure is? cause? results in?

Answer 6

failure of gas exchange
cause: acute, severe pulmonary insult (anything that causes fluid filling or collapse of alveoli)- i.e. pneumonia, pulmonary hemmorrhage
results in: hypoxemia w/ low or normal CO2

Question 7

two types of acute hypoxemis resp failure

Answer 7

diffuse (lungs) and focal (part of lung)

Question 8

hypocapnia with acute hypoxemic resp failure ?…

Answer 8

hypoxic ventilatory stimulation –> hyperventilation decreases CO2 in blood

Question 9

what is acute hypoventilatory failure? cause? result?

Answer 9

gas exchange is normal but poor ventilation

cause: impaired effort
result: hypercapnia

Question 10

causes of hypoventilatory failure?

Answer 10

decreased vent. capacity- neuroMusc. disorders (i.e.ALS) or CNS depression (i.e. overdose)
increased work of breathing: pulmonary or extrapulmonary

Question 11

consequences of ARF: two main types and what they cause

Answer 11

hypoxemia (low O2)–> tissue hypoxia and metabolic acidosis

hypercapnia (high CO2)–> CNS effects, resp acidosis (more severe effects from hypercapnia than hypoxia)

Question 12

3 steps to txt ARF

Answer 12

1. fix the cause- while assessing ABGs + ventilation
2. O2 (for hypoxia or hypercapnia)
3. add mechanical vent if not enough O2

Question 13

acid/base distrubances from ARF: resp. acidosis vs resp alkalosis

Answer 13

resp. acidosis = hypercapnia = alveolar hypoventilation

resp alkalosis = hypocapnia = alveolar hyperventilation

Question 14

incr. ventilation = ____ pH

Answer 14

increased (more basic)

Question 15

to minimize hypoxemia for ARF pts, you must correct the ABGs to the _____

Answer 15

pt’s baseline

intervene with O2- nasal cannula (40% O2) or full face mask (100% O2)

Question 16

mechanical ventilation: easy Hadley approach

Answer 16

consult resp. therapist for best ventilatory support

Question 17

ARDS- what is it and what response causes it?

Answer 17

Acute/Adult resp. distress syndrome : pulmonary edema that is NOT caused by HF.
inflamm response: protein leakage from capillaries into the interstitial space- H2O from alveoli follows proteins = dec. gas exchange

Question 18

what does surfactant do?

Answer 18

dec. surface tension, acts as a detergent in the lungs to keep alveoli open (so H2O hydrostatic forces down keep them closed)

Question 19

pathophys of ARDS

Answer 19

pulm injury causes inflamm response and leads to resp failure

Question 20

what can happen if you ventilate under high pressure?

Answer 20

alveoli can pop

Question 21

txt of ARDS

Answer 21

treat infection/injury that caused it

-mechanical vent. if necessary