Pulse OX ppt what what bitches

Question 1

Arterial blood oxygen saturation SaO2 is determined by what

Answer 1

by the ratio of oxygenated (Sat Hgb) to deoxygenated hgd

Question 2

A SPO1 of 90 is what PaO2

Answer 2

60

Question 3

what if the main goal in reading the pulse ox

Answer 3

find out what teh pts PaO2 is and if SPO2 is not 100% or things do not match find out why! don’t just give O2

Question 4

SpO2 does what to VQ mismatch at higher doses

Answer 4

Mask it

Question 5

This higher the FiO2 the more you mask what

Answer 5

VQ mismatch

Question 6

Oxyhemoglobin absorbs what light

Answer 6

infra red (940 nm)

Question 7

deoxyhemogobin absorbs what light

Answer 7

Visible light (660 nm)

Question 8

how does the pulse OX work?

Answer 8

• Prob with 2 lights one red, one infrared
• sensor detects the ratio of red/infra red absorption ratios
• detection of absorption during pulsatile flow several times/sec
• calc is done from the Beer-Lambert law

Question 9

Isobestic point

Answer 9

means absorbs at the same point, and represents the worst site to measure (uses with beer-lambert) this is why each oxygenated and de-oxygenated hgb is measured at different numbers

Question 10

Advantages of Pulse OX

Answer 10

non-invasive
easy to apply
Continuous monitoring
early detection of desat
Inexpensive

Question 11

SPO2 of 85% = PaO2 what? and will you see cyanosis?

Answer 11

55mm

nope

Question 12

SPO2 of 20% = PaO2 what? and will you see cyanosis?

Answer 12

40 mm

yes

Question 13

Disadvantages of Pulse OX

Answer 13

artifact
Inaccurate below SPO2 70%
rare risk of burns in poor perfusion states

Question 14

Lag times
ear
finger
toe

Answer 14

ear- 7-20 sec
finger- 20-35 sec
toe- 40-70 secs

Question 15

What type of low flow or low pulsatile flow states cause inaccuries in pulse ox

Answer 15

Cardiac bypass
hypotension
b/p cuff inflation
tourniquets
vasoconstriction

Question 16

a Hgb < ___ gives an underestimation of SPO2

Answer 16

<10

Question 17

What dyshemoglobins cause pulse ox inaccuracies

Answer 17

Carboxyhemoglobin

Methemoglobin

Question 18

what dyes cause pulse ox Inaccuracies

Answer 18

methylene blue
indigo carmine (lesser degree)

Question 19

What other things can make Pulse OX inaccurate

Answer 19

ambient light
deep skin pigment
electrocautery
excessive motion
Fingernail polish

Question 20

Ficks law states what

Answer 20

Diffusion rate of gas is directly
proportional to:
–Partial pressure gradient
–Membrane area
–Solubility of gas in membrane

Diffusion rate of gas is inversely
proportional to:
–Membrane thickness
–Square root of the molecular weight