Clinical Monitoring 6/5 Flashcards

Test 1 (81 cards)

1
Q

Monitoring standards for CRNAs are set by _______ (2)

A

AANA
ASA

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2
Q

What are the monitoring standards?

A
  1. Oxygenation
    -clinical observation
    -pulse ox
    -ABGs (as indicated)
  2. Ventilation
    -auscultation
    -chest excursion
    -ETCO2
    -pressure monitors/flow volume loops (as indicated)
  3. Cardiovascular
    -ECG
    -auscultation (as needed)
    -BP/HR q5min (at minimum)
  4. Thermal regulation
    -when clinically significant changes in body temp are anticipated or suspected
  5. Neuromuscular
    -as indicated –> when administered a NMB
  6. Positioning/protective measures
    -nerve damage can be caused dt positioning
  7. Additional means depend depending on needs
    -Ex) blood loss – giving blood; biz monitoring

Any omission of the above must be charted with a valid reason

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3
Q

Pulse ox mechanics is based on the ________ law, which is the “law of _______”. Describe it.

A

Beer-Lambert Law

Absorption

Visible light passing thru a chemical solution of fixed geometry experiences absorption proportional to the concentration of the solute

(More solute = more absorption you see, less solute = less absorption you see)

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4
Q

What happens to light when it goes thru matter?

A

it is transmitted, absorb, or reflected

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5
Q

What are the different types of Hb that are normally bound? (4)

A

Oxyhemoglobin (HbO2)
Reduced Hb
Methemoglobin (metHb)
Carboxyhemoglobin (COHb)

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6
Q

The most accurate type of oximetry & gold standard is ______. It operates off _____ wavelengths. When do we use this?

A

Co-oximetry

4

If there are 2 types of Hb showing the same dt only using 2 wavelengths w/ pulse oximetry

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7
Q

Normal pulse oximetry works off ____ wavelengths. What are the value of those?

A

2

660 & 940 nanometers

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8
Q

Pulse ox measure oxygenation from ____ blood. Why?

A

Arterial

Pulsatile expansion of the artery increases length of light path –> increases absorbency

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9
Q

From a pulse ox, light is transmitted through…. (give order)

A

Skin –> soft tissue –> venous blood –> arterial blood –> capillary blood

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10
Q

Equation: Pulse oximetry

A

Flucating component (pulsatile) / Nonflucating component for each wavelength

Ex) (AC 660/DC 660) / (AC 940/DC 940)

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11
Q

Whats the difference between SaO2 & SpO2?

A

SaO2 – ARTERIAL SATURATION

SpO2 – THIS IS THE PULSE OX READING

2-3% difference

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12
Q

What can cause artifact w/ pulse oximetry? (5)

A
  1. Ambient light
    -solved by altering red/infrared –> machine set to do this
  2. Low perfusion
    -decreased BP; hypovolemia
    -signal & artifact amplified
  3. Venus blood pulsations
    -slower to report changes
  4. Additional light absorbers
    -intravenous dyes & pulseox that uses 8 wavelengths
  5. Additional forms of Hb
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13
Q

What are the monitoring standards that aren’t required with every case– Only as indicated? (4)

A

ABG’s
Pressure monitors/flow volume loops
Thermoregulation (still have to take temps)
Neuromuscular monitoring

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14
Q

We have to document vital signs every ____ minutes, this is the minimum

A

5

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15
Q

What happens when O2 is taken up into the lungs?

A

Blood is nearly 100% saturated

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16
Q

During passes through systemic capillaries, _______ amounts of O2 is released & there is a small _______ in PaO2 (tension)

A

large

small

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17
Q

What happens to the Oxyhemoglobin-dissociation curve if the blood is poorly saturated?

A

Curve goes to the L

Small amounts of O2 released (increased affinity) & LARGE drop in PaO2 (tension)

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18
Q

Why is it important to keep O2 sats above 90%?

A

Below that we see large drops in PaO2 (tension)

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19
Q

PaO2 =

A

PP of O2 in the ARTERY

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20
Q

At 90% saturation, the PaO2 is about _____. What is the revelance of this point?

A

60 mmHg

Above this point: slow rise of PaO2 tension/PP of O2 in artery
-Small change in PaO2 = small change in SpO2
-Hb is near fully saturated
-Slope more horizontal

Below this point: rapid decreased in PaO2 tension/PP of O2 in artery when saturation decreases
-Small changes in PaO2 = LARGE drops in SpO2
-Slope very steep/more vertical

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21
Q

What is the x & y axis of the Oxyhemoglobin-dissociation curve?

A

y (vertical): arterial saturation

x (horizontal): arterial O2 tension which is the PP of O2 in the arteries

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22
Q

A R shift in the Oxyhemoglobin-dissociation curve causes ______ O2 affinity. What does this mean? What causes this? (3)

A

Reduced

Releases O2 easier from Hb

Increased:
Temp
2-3 DPG
Hydrogen ions –> acidosis/decreased pH

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23
Q

________ (2) are sensitive to vasoconstriction. What can this cause?

A

Fingers & Toes

inaccurate readings w/o enough pulsatile flow

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23
Q

A L shift in the Oxyhemoglobin-dissociation curve causes ______ O2 affinity. What does this mean? What causes this? (3)

A

Increased

Hb doesnt want to release O2

Decreased:
Temp
2-3 DPG
Hydrogen ions –> alkalosis/increased pH

Increased carbon monoxide (CO)

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24
T/F: dark polish/synthetic nails inhibit transmission for pulse ox symmetry
T
25
Detection of desaturation/saturation is slower ________. What does this mean? What consideration should we have?
peripherally With unstable/fluctuating conditions like unstable HR & BP --> pulse ox may be slower to detect changes With unstable conditions --> use central location: Nose Earlobe Forehead (anything closer to the trunk)
26
Pulse ox should not be placed on _______. Why?
Index finger When waking up patient has a tendency to scratch --> **increase risk for corneal abrasion**
27
_______ are more reliable with pulse ox for epidural blocks. Why?
Toes dt increase vasodilation below the block
28
___________ (3) are less affected by vasoconstriction. Why is it relevant?
Tongue Cheek Forehead Reflects desaturation/saturation quicker --> prevents treating inaccuracies
29
What are the advantages of pulse ox? (10)
1. Accuracy +/-2% when compared to ABG's when sats >70% 2. Not affected by anesthetic vapors 3. Non-Invasive 4. Continuous 5. May indicate decreased CO 6. Convenient 7. Tone modulation --> hear changes when sats drop 8. Probe variety -- clamp vs stickers 9. Battery operated --> portable 10. Economical -- can get basically anywhere & not expensive
30
What are limitations to pulse ox? (10)
1. Failure to determine saturation if very vasoconstricted or sats very low 2. Poor function with poor perfusion 3. Difficulty in detecting high PP 4. Delayed hypoxic event detection -- esp in peripheries 5. Erratic performance with dysrhythmia --> Afib/Aflutter may not be able to pick up 6. Inaccuracies w/ different Hb -- Ex CO 7. Inaccuracies with dyes 8. Optical interference 9. Nail polish & coverings 10. Motion artifacts
31
What are the 3 most common dyes that we use? Which absorbs the worst with pulse ox & gives the most inaccurate readings?
Methylene blue Indocyanine green Indigo carmine Methylene blue
32
Carboxyhemoglobin (COHb) absorbs as much light in the ______ nanometer range as _______ does. What consideration should we have with this?
660 Oxyhemoglobin Falsely elevate SpO2 readings
33
Each 1% increase in COHb will falsely increase SpO2 by ___%
1%
34
smokers have _______% COHb. What consideration should we have with this?
>6% (Remember Schmidty said 1% was normal) SpO2 falsely elevated by 6% or more Ex) SpO2 read 94% = actual PaO2 is 88 or less
35
____% of NCE boards is equipment related
15%
36
History: Knowledge of pulse
China & India
37
History: Circulatory system understanding & correlation between heartbeat & pulse
Dr. William Harvey 1600
38
History: 1st recorded blood pressure
Reverend Hales 1733 **Was recorded on a horse**
39
History: 1st Sphygmomanometer
Samuel Von Basch 1881
40
History: BP measured w/ systolic and diastolic pressures/sounds --> Kororkoff sounds
1905
41
The different sounds used to measure SBP & DBP are called _____. What is the definition of this?
Kororkoff sounds Series of audible frequencies produced by turbulent flow beyond the partially occluding cuff dt the artery being partially occluded --> produces **Turbulent flow (Non-laminar flow)**
42
What are the 3 phases of Korotkoff sounds?
Phase 1: most turbulent/audible (SBP) Phase 2-3: sound changes Phase 4-5: muffled/absent (DBP)
43
Equation: Mean BP (MAP)
((2 x DP) + SP) / 3
44
What are limitations to auscultation (Old fashioned BP)?
1. Decrease peripheral flow -shock -intense vasoconstriction 2. Changes in vessel compliance (stiff diastolic) -severe edema -calcific arteriosclerosis -normal aging (these increase DBP #) 3. Shivering 4. Incorrect cuff size
45
If the BP cuff size is too small it will show a false ______ in BP & if too large it will show a false _______ in BP
Increase (HTN) Decrease (hypotension)
46
In BP cuffs, you want the maximum cuff pressure to be ______ in adult adults & ______ for neonates
300 mmHg 150 mmHg
47
Why is it important that the BP cuff has a means to prevent extended inflation?
Machine needs to know its been inflated for a few mins & deflate on its own --> help prevent nerve damage
48
The BP cuff bladder needs to be ____ of arm circumference & ____ of length of upper arm.
40% 80%
49
How does automatic non-invasive BP work? How is SBP calculated? How do you identify MAP?
Based on oscillometry SBP & DBP calculated from algorithm SBP = 25-50% of MAP amplitude MAP = highest amplitude
50
With automatic non-invasive BP which value is the lease accurate?
DBP
51
Automatic non-invasive BP is almost equal to A-line pressures under what condition?
When MAP 75mmHg or lower
52
According to the book, non-invasive BP has a ______ difference when compared to A-line. What is the reality tho? What is the most important thing for us to do w/ BP?
+/- 5 mmHg Reality: large variances -underestimates MAP during HTN -overestimates MAP during hypotension -Ankle, thigh, calf cuffs never validated Averaging, trending necessary for measurements to be reliable -never go off 1 number
53
What are the advantages of non-invasive BP?
-automaticity (can set to automatically take) -simplicity -non-invasive -reliable(ish) -monitor integration --> pulse ox won't alarm if BP monitor inflates
54
What are the disadvantages of non-invasive BP?
1. unsuitable for rapidly changing situations --> won't trend fast enough 2. Patient discomfort w/ increased freq 3. Clinical limitations -- w/ extreme HR & pressures 4. Trauma -- dt increased freq -coagulopathy -peripheral neuropathy -arterial/Venous insufficiency -compartment syndrome
55
What are indications for an A-line? (5)
1. Continuous, real time monitoring (beat to beat) 2. Planned pharmacologic manipulation 3. Repeated blood sampling 4. Determination of volume responsiveness 5. IABP -- timing of counterpulsation
56
The most common site for an A-line is ______. What other benefits are there to this area? (3)
Radial Easy to access Clean compared to fem Complications are uncommon
57
What 2 arteries does Allen's test involve? What is the purpose of this test? Describe the entire test
Radial & Ulnar artery Purpose: to see if we put A-line in radial artery & it occludes -- **is there enough flow from Ulnar artery** to prevent ischemia in hand Test: 1. Compress both radial & ulnar arteries 2. Pt make tight fist --> Exsanguinating venous blood out of hand 3. Pt open hand 4. Release ulnar artery only 5. Color of palm should return in less than 10 secs if ulnar artery flow is sufficient
58
Slogoff studies identified what regarding the allen's test, occlusion & ischemia?
25% evidence of radial artery occlusion after decannulation --> no evidence of ischemia Allen's test is predictive of occlusion but **not so much of ischemia**
59
_______ is the gold standard for determining **occlusion** w A-line placement in the radial artery but not _____. How accurate is it?
Allen's test Ischemia 80% accurate for color change at 5 secs
60
The angle for A-line placement is _____
30-45 degrees
61
What do we need to do to help w/ A-line placement in radial art? (2)
Towel under wrist -- helps bring radial artery up Tape all 5 fingers down (esp thumb) -Moving thumb = radial artery moving
62
The main technique used for A-line placement is _________. Describe it
Seldinger's Technique 1. Insert needle -- see flashback of blood 2. Pass guidewire through needle 3. Remove needle once guide wire is substantially through catheter 4. Insert catheter fully over wire
63
What is the 2nd way to place an A-line called? Why is it not the best technique? Describe it.
Transfixion technique Studies say not associated w/ more frequent complications BUT: -Increased hematoma -increase art lines that don't hold up Procedure: 1. Same positioning/prep as Seldinger's Technique **2. Front & back walls are punctured intentionally** 3. Needle removed 4. Catheter withdrawn into pile blood flow appears --> advanced catheter further into artery
64
What are the other common sites for A-line placement? (5)
1. Brachial 2. Posterior tibial 3. Axillary 4. Dorsalis Pedis 5. Femoral
65
Why do we try and avoid the brachial artery when placing A-line?
If occluded --> lose significant part of arm
66
The automatic flush w/ A-lines goes at _____. What does it prevent? What do we use in the flush? What do we not use anymore & why?
1-3 ml/hr Prevent thrombus formation We use NS now vs heparin & dextrose We dont use heparin bc risk of HIT & DM w/ dextrose
67
Zeroing the A-line references pressures against ________
Atmospheric air
68
leveling the A-line is at the _______, which is ________ visually.
Aortic root Mid axillary line/ mid chest
69
How do we maximize the waveforms with A-lines? (3)
1. Limit stopcocks -just 1 as close to artery as you can get for blood draws 2. Limit tubing length 3. Use non-distensible tubing -not IV tubing or any other tubing that easily expands --> it absorbs pressure & wont see a waveform
70
What are the 6 types of waveforms of an A-line in the order they appear?
1. Systolic upstroke 2. Systolic peak pressure 3. Systolic decline 4. Dichotic notch 5. diastolic runoff 6. end-diastolic pressure
71
Why does the morphology change when arterial pressure measured at different sites? How does this affect the waveform? (5)
Impedence changes along vascular tree As pressure wave move to periphery: 1. Arterial upstroke steeper 2. Systolic peak higher 3. Dicrotic notch later 4. End-diastolic pressure lower 5. MAP changes very little
72
How is the Aortic arch A-line waveform different from the Fem artery A-line?
Femoral: higher systolic peak -lower dicrotic notch
73
Waveforms made from A-line are a summation of ________ waves. What are they? (2)
sine waves Fundamental waves + harmonic waves
74
________ is an analysis of the summation of sine waves w/ A-line waveforms
Fourier analysis
75
What is the Squared Wave Test? How is it done?
Way to make sure that A-line is correctly calculated -- not overdamped or underdamped Push flush button --> see square wave -w/i a few secs should return to normal
76
Compare an overdamped (5) vs underdamped A-line waveform
Underdampened: Systolic pressure elevated Overdamped: -SQUISHED -Systolic pressure decreased -Absent dicrotic notch -narrow pulse pressure -loss of detail
77
Overdamped waveforms are ______
squished
78
All A-line systems have a partially built-in ______ capability. What does this help with? (3)
damping -Helps make system more accurate --> decreases system resonace -Prevents exaggerated waveforms -prevents waveforms from looking flat
79
What are pathologies that cause A-line waveform changes? (8)
1. Age -- lack of distensibility 2. Atherosclerosis 3. Embolism 4. Arterial dissection 5. Shock/hypotension 6. Hypothermia 7. Vasopressor infusions 8. Over/underdamping
80
What are complications w/ A-lines? (5)
1. Distal ischemia or pseudoaneurysm 2. Hemorrhage 3. Hematoma 4. Local infection 5. Peripheral neuropathy