Exam 1 (Monitoring) Flashcards
What monitoring device is always necessary for anesthesia?
EtCO2, even with nasal cannula
Red wavelengths operate at what wavelength?
660nm
Infrared wavelengths of light operate at?
940nm
deO2Hb absorbs more or less red light than O2Hb?
more
O2Hb absorbs more or less infrared light than deO2Hb?
less
What is the formula for the DC & AC ratio?
R= (AC660 / DC 660) / (AC 940 / DC 940)
At what nm does carboxyhemoglobin absorb as much light as O2Hb?
660nm
What Hb does not abosrb light at 940nm?
Carboxyhemoglobin
Each 1% increase in COHb will increase/decrease SpO2 by ____%?
- Increase
- 1%
Venous blood pulsations will increase/decrease SpO2?
decrease
Will methylene blue injection increase or decrease SpO2?
decrease
When are PulseOx and ABG within +/- 2%?
When sats >70%
Are sats reading affected by anesthetic vapors?
No
What are some disadvantages to PulseOx?
- Poor function with poor perfusion
- Delayed hypoxic event detection
- Erratic w/ dysrhythmias
What are some disadvantages to PulseOx?
- Poor function with poor perfusion
- Delayed hypoxic event detection
- Erratic w/ dysrhythmias
- Inaccurate w/ different hemoglobins
- etc
Where should PulseOx not be placed?
Index fingers to prevent corneal abbrasions
Where should PulseOx be placed with epidurals?
On the toe d/t vasodilation
What is phase I of the Korotkoff sounds?
What about phase V?
- SBP
- DBP (very hard to hear in kids)
What part of automatic BP monitoring is in most agreement with invasive?
What about least in agreement?
- The MAP, it is the closet to invasive
- Least agreement is the SBP
What conditions produce errors with non-invasive BP monitoring?
How are the reading affected>?
- atherosclerosis
- edema
- obesity
- chronic HTN
- SBP will read low & DBP will read high
The MAP will be ____ during hypertension?
What about hypotension?
- Underestimated
- Overestimated
Use caution with non-invasive BP monitoring in Pt’s with following conditions?
- severe coagulopathies
- peripheral neuropathies
- arterial/venous insufficiency
- recent thrombolytic therapy
Wave #1 of an arterial line waveform comes when?
After the R-wave
With arterial waveforms as the measuring site moves more distal, what happens to the waveform (4)?
- arterial upstroke is steeper
- systolic peak is higher
- Dicrotic notch is later
- End-diastolic pressure is lower
How many waveforms are required for an acurate a-line tracing?
6-10 harmonic waves
Multiple dicrotic notches means the the A-line bag is?
Underdamped
What measurement is false with an underdamped A-line?
SBP is elevated
How does the inspiratory phase of positive pressure ventilation affect intra-thoracic pressure & LV preload & afterload?
- Intra-thoracic pressure increases
- LV Preload increases
- LV afterload decreases
How does inspiratory phase of positive pressure ventilation affect PVR, RV pre- & afterload, & venous return?
- PVR increases
- RV preload decreases
- RV afterload increases
- venous return decreases
Increased SPV is an indication of what?
hypovolemia
What is the difference between SPV & PPV?
- SPV is measured at end-expiratory
- PPV is measured over the entire respiratory cycle
Stroke volume variation correlated resistance & compliance based on?
Age & gender
What challenges does the Mainstream sampling have?
- Water vapor
- secretions
- blood
- more interfaces for disconnects
What challenges does the Side-stream sampling have?
- kinked sample tubing
- water vapor
- failure of sampling pump
- leaks in line
- slow response time
Which gas is not absorbed by IR radiation?
O2
Side-stream analyzers do not account for what in values?
H2O
What are the Cons of Fuel or Galvanic cell O2 analyzers?
- Short life span (months)
- Slow response time (monitor O2 in inspiratory limb)
What are the Pros of Paramagnetic O2 analyzers?
- Rapid response
- Breath by breath monitoring
The total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of each gas is who’s law?
Dalton
Which type of SSEP is MOST COMMONLY monitored during surgical procedures?
Short-latency
Which of the four types of adult hemoglobin is LEAST LIKELY to be measured at the 940 nm wavelength?
Carboxyhemoglobin
What is the amount of tidal volume exhaled during phase I?
1/3
Physiologic effects of hypocarbia are:
- respiratory alkalosis and increased ICP.
- blunting of respiratory drive and respiratory acidosis.
- respiratory alkalosis and potassium shift to intravascular space.
- blunting of respiratory drive and decreased cerebral blood flow.
blunting of respiratory drive and decreased cerebral blood flow.
The capnogram has a prolonged upstroke with an alpha angle >110 degrees, what is the problem causing the change?
The ETT is partially obstructed.
What are the LIKELY causes of decreased EtCO2?
- Hypothermia and poor gas sampling.
- Hyperventilation and increased metabolic rate.
- Hyperthermia and cardiac arrest.
- Hypothermia and rebreathing.
Hypothermia and poor gas sampling.
