111114 response to hypoxemia

Question 1

central chemoreceptors are responsible for what percentage of the response to PaCO2?

Answer 1

70

Question 2

what does the controller sense in terms of PaO2?

Answer 2

checks if PaO2 is over 70 mm Hg

Question 3

what happens when PCO2 acutely increases?

Answer 3

alveolar ventilation increases exponentially

Question 4

what determines how much oxygen binds to hemoglobin?

Answer 4

the PARTIAL PRESSURE OF O2

Question 5

the dissolved O2 is dependent on

Answer 5

PARTIAL PRESSURE OF O2

Question 6

the controller assess if the PaCO2 is within? and the pH?

Answer 6

35-45

7.35-7.45

Question 7

signs of hypercapnic respiratory failure

Answer 7

somnolence
asterixis-tremor
doesn’t respond to pain
chest wall barely moves

Question 8

what happens to lungs with COPD in inhale and exhale?

Answer 8

more compliant
so lung will expand
but they have a harder time recoiling

Question 9

how do chronic hypercapnic COPD pts adapt to increasing CO2?

Answer 9

kidney retain bicarbonate

respiratory drive decreases
so in pt with chronic hypercapnia, the respiratory drive is NOT maintained by CO2 anymore but by PaO2

Question 10

what happens when you give a chronic hypercapnic pt O2?

Answer 10

eliminates the only drive to breathe they have left (that of O2)

PaCO2 will increase

Question 11

why is too much O2 bad for severe COPD?

Answer 11

eliminates the only drive to breathe they have left (that of O2)

hypoxic vasodilation occurs but the lung is destroyed, so you have created a V/Q mismatch and worsened the hypercapnia

too much oxygen causes hemoglobin molecule to be all bound up so that CO2 produced at the cellular level cannot bind to hemoglobin and be buffered

Question 12

what happens when the diaphragm is not working?

Answer 12

abdomen now sinks–called paradoxical abdominal breathing