ARDS/respiratory failure

Question 1

3 reasons for respiratory failure

Answer 1

1. failure to ventilate (high PaCO2)
2. failure to oxygenate (low PaO2)
3. failure to protect airways (low GCS/obstruction)

Question 2

5 pathophys mechanisms for hypoxemia

Answer 2

1. V/Q mismatch d/t obstruction, filling or capilarry destruction
2. R to L shunt (anatomic and physiological)
3. alveolar hypoventilation
4. diffusion impairment (causes it in stressed states)
5. shock

Question 3

which type of respiratory support does this describe?

• Flow rate is lower than peak inspiratory flow rate
• Ambient air incorporated depending on minute ventilation
• sick people get less FiO2 with this & we give non-rebreather mask to fix this

Answer 3

low flow O2

Question 4

which type of respiratory support does this describe?

• provides up to 100% FiO2
• blends oxygen & air up to 60L/min and heats it to 37C
• provides PEEP
• decreases pharyngeal dead space

Answer 4

heated humidified high flow nasal cannula (high flow O2)

Question 5

which type of respiratory support does this describe?

closed system via helmet when being used for AHRF

Answer 5

CPAP

Question 6

what type of resp. support does this?

• provides up to 100% FiO2
• increases mean airway pressure–> PaO2
• decreases cardiac preload and afterload
• provides airway stenting for COPD
• decreases WOB and resistance

Answer 6

BIPAP/BPAP

Question 7

4 indications for BPAP

Answer 7

• cardiogenic pulmonary edema
• acute exacerbation of COPD
• neuromuscular weakness
• +/-AHRF

Question 8

2 C/I to BPAP

Answer 8

• failure to protect airway
• trauma or tumor

Question 9

acute hypoxemic respiratory failure (type 1) is?

Answer 9

SaO2 under 88%
or
PaO2 under 55%

Question 10

effects of isolated mild hypoxemia (PaO2s in 50s)

Answer 10

neurocognitive slowing

Question 11

effects of severe hypoxemia (PaO2 < 50) (4)

Answer 11

• somnolence
• seizures
• cardiopulmonary instability
• brain damage

Question 12

Acute hypercapnic respiratory failure (type 2) is when..

Answer 12

PaCO2 over 50

Question 13

5 effects of hypercapnia

Answer 13

• acidosis
• increased CNS blood flow (HA, papilledema)
• tremor
• slurred speech
• asterixis–> CNS depression

Question 14

4 causes of type 2 resp failure

Answer 14

• asthma/COPD exacerbation
• CNS depression
• neuromuscular weakness
• massive PE

Question 15

tx for Mild hypoxemia, normal or slightly increased WOB

Answer 15

nasal cannula/oxymask

Question 16

tx for moderate/severe hypoxemia, increased WOB

Answer 16

HHFNC

Question 17

tx of hypoxemic resp. failure w/ CHF, COPD, neuromuscular weakness

Answer 17

BIPAP

Question 18

tx for Very severe hypoxemia or WOB, failure of first 3 options, inability to protect airway

Answer 18

invasive mechanical ventilation

Question 19

managment of hypercapnic resp failure (3)

Answer 19

• tx underlying problem
• BPAP
• invasive mechanical ventilation

Question 20

ARDS should be suspected in patients w/ what 3 clinical manifestations?

from PPP

Answer 20

1. acute onset of progressive profound dyspnea
2. hypoxemia
3. alveolar infiltrates w/in 6-72 hrs of an inciting event up to 7 days

Question 21

measurement that determines severity of hypoxemia

Answer 21

PaO2/FiO2

Question 22

mild vs moderate vs severe ARDS

Answer 22

• mild: 201-300
• moderate: 101- 200
• severe: 100 or less

Question 23

some sx of ARDS (4)

Answer 23

• SOB
• DOE
• tachypnea
• hypotension

Question 24

pH, paO2 and paCO2 initially with ARDS

Answer 24

pH increases
others decrease

respiratory alkalosis

Question 25

as ARDS progresses what happens to pH, bicarb and PaCO2

Answer 25

• pH decreases
• PaCO2 high (resp. acidosis)
• bicarb low (metabolic acidosis)