Pulse OX ppt what what bitches Flashcards

do be a master of the pulse OX

1
Q

Arterial blood oxygen saturation SaO2 is determined by what

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

A SPO1 of 90 is what PaO2

A

60

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what if the main goal in reading the pulse ox

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

SpO2 does what to VQ mismatch at higher doses

A

Mask it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

This higher the FiO2 the more you mask what

A

VQ mismatch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Oxyhemoglobin absorbs what light

A

infra red (940 nm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

deoxyhemogobin absorbs what light

A

Visible light (660 nm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how does the pulse OX work?

A
  • 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
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Isobestic point

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Advantages of Pulse OX

A
non-invasive
easy to apply
Continuous monitoring
early detection of desat
Inexpensive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

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

A

55mm

nope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

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

A

40 mm

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Disadvantages of Pulse OX

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Lag times
ear
finger
toe

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

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

A
Cardiac bypass
hypotension
b/p cuff inflation
tourniquets
vasoconstriction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

a Hgb < ___ gives an underestimation of SPO2

A

<10

17
Q

What dyshemoglobins cause pulse ox inaccuracies

A

Carboxyhemoglobin

Methemoglobin

18
Q

what dyes cause pulse ox Inaccuracies

A
methylene blue
indigo carmine (lesser degree)
19
Q

What other things can make Pulse OX inaccurate

A
ambient light
deep skin pigment
electrocautery
excessive motion
Fingernail polish
20
Q

Ficks law states what

A
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