Monitoring Flashcards

1
Q

What is included in Standard V (monitoring?

A
A.) ventilation
B.) oxygenation
C.) CV status
D.) body temp
E.) neuromuscular function and status
F.) patient positioning
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2
Q

What is absolutely required to monitor ventilation?

A

Pulse ox
ETO2
(Both continuously)

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3
Q

What are indications for using a precordial/esophageal stethoscope?

A

Since it provides continuous auditory confirmation of ventilation., quality of breath sounds, HR regularity, and quality of heart tones it is useful in detecting subtle changes
—> muffled hearts tones are associated with decreased CO
(Also has temp probe built into it)

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4
Q

When is using an esophageal stethoscope contraindicated?

A

If pt has a hx of esophageal varies, strictures or bariatric surgery

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5
Q

What happens if esophageal stethoscope slides into trachea, and what do you do if this happens?

A

A gas leak will occur around ETT

—> pull esophageal catheter out/back and start over

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6
Q

What are the 2 wavelengths of light in a pulse ox?

A

Red: 660nm—> absorbed by deoxyhemoglobin
Infrared: 940 nm—> absorbed by oxyhemoglobin

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7
Q

How does a pulse ox calculate O2 sats?

Is it ever contraindicated to use a pulse ox?

A

Calculates both fractions of deoxyhemoglobin to oxyhemoglobin passing through an arterial bed
- ratio of 660:940 light

No- use it!

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8
Q

What is Beer Lambert’s Law?

A

Basis for how we do oxygen saturation

-in red region oxyhgb. Absorbs less light than deoxyhgb. And vice versa

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9
Q

What are some reasons for inaccurate pulse ox readings?

A
  • vasoconstriction
  • hypothermia
  • hypotension
  • methylene blue: messes with absorption of light sensor, usually transient-does not mean a real drop in O2
  • methemoglobin-absorbs light equally to oxyhemoglobin
  • carboxyhemoglobin-attaches well to RBC- will show 100% sat, not all of this is O2. PaO2 will be very low
  • sickle cells
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10
Q

How does ETCO2/capnography work?

A

Uses infrared

  • continuous waveform of inhaled and exhaled concentration of CO2
  • waveform provides info on adequacy of ventilation and confirms ETT placement in respiratory tract
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11
Q

What does the absence of an ETCO2 waveform mean?

A
  • esophageal intubation
  • disconnect from circuit/breathing system
  • cardiac arrest
  • air emboli
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12
Q

How accurate is ETCO2 compared to PaCO2?

A

ETCO2 is 2-5 torr less than arterial PaO2

- gap widens in smokers (can’t fully exhale)

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13
Q

In the capnography waveform what does phase I (A-B) represent?

A

Exhalation of deadspace

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14
Q

In the capnography waveform what does phase II (B-C) represent?

A

Exhalation of deadspace and alveolar gas

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15
Q

In the capnography waveform what does phase III (C-D) represent?

A

Exhalation of alveolar gas

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16
Q

In the capnography waveform what does phase IV (D-E) represent?

A

Inspiration of fresh gas, not containing CO2- return of wave to baseline

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17
Q

Other than the pulse ox, what are additional respiratory monitors?

A

Multiple gas analyzers

- continuous analysis of inhaled and exhaled concentrations of respiratory and anesthetic gases (no contraindications)

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18
Q

What is mass spectrometry and how is it used regarding anesthesia gases?

A

Gas is bombarded with electrons—> this creates fragments of charged particles

  • these particles are separated and identified based on mass
    • type and concentration of gas can be determined (from an exhaled gas sample to determine amt gas exhaled…ETCO2
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19
Q

Can mass spectrometry analyze more than one pt at a time?

A

Yes, up to 32 pts can be anazlyzed on 1 central computer

- as of 1975 so longer produced, but still may be used in places

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20
Q

What is Raman spectroscopy?

A

High power argan laser produces photons that collide with gas molecules

  • scattered photons are measure in a spectrum that identifies each gas and its concentration
  • measures “Raman scattered light” from these gases
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21
Q

What is monochromatic infrared Spectrometry?

A

infrared beam with wavelength of 3.3nm is passed through a gas sample

  • the absorbed spectrum of halogenated gases is similar at this wavelength
  • monitor must be programmed with selected agent
  • concentration of gas is then measured
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22
Q

What is polychromatic infrared spectrometry?

A
  • infrared beam at 7-13 nm is passed through anesthetic gas sample
  • absorption spectrum of halogenated gases is different at this wavelength
  • monitor automatically identifies inhaled agent and can describe concentrations given
  • if you change agents- the monitor can measure both simultaneously
23
Q

How do you monitor positive pressure created by mechanical ventilation?

A

Peak inspiratory pressure gauge

24
Q

How does the peak insp pressure gauge monitor low pressure disconnect?

A
  • alarm indicates minimum inspired pressure did not achieve pre determined level
    • caused by disconnect or leak in breathing system
      • increases with insuflation—> expected to happen
25
Q

How does the peak insp. Pressure gauge let you know there is high peak insp. Pressure?

A
  • alarm indicating positive airway pressure is greater than the set value: usually set at 40cmH2O
  • may indicated low pulmonary compliance
  • check for obstruction in system
26
Q

What could be a cause for the high peak pressure alarm?

A
  • ARDS
  • pulmonary edema
  • asthma
  • paralytic wearing off
  • kinked ETT
  • mucous plug
27
Q

What are some vigilant “real time” breathing assessments?

A
  • hand on reservoir bag
  • auscultation with precordial stethoscope
  • observation of chest movements
  • RR, effort and depth
28
Q

How often should you record HR and BP?

A

At least every 5 minutes

29
Q

What does an ECG record?

A

Electrical potentials generated by myocardial cells

30
Q

Is ECG a measure of heart function?

A

NO

It is possible to have a normal ECG with no effective CO

31
Q

Why must you always have a pre-induction rhythm strip for comparison?

A

Can detect:
- arrhythmias
- MI
- conduction abnormalities
- electrolyte disturbances
* make sure you can hear the beat for each QRS complex
(1 my signal change can indicate 10mm on paper monitor strip)

32
Q

What are normal intervals for an ECG?

A

PR: 0.12-0.20 sec
QRS: 0.06-0.10 sec
QT: < or = 0.40

33
Q

What is a TEE and what makes it useful?

A

Mini-high frequency (5MHz) ultrasound transducer

  • lies in lower esophagus, in close direct fluid contact with posterior heart
  • images are superb since their is no interference from lung tissue
34
Q

What is true in healthy hearts?

A

Right and left ventricular performance is parallel

- LV filling pressure can be assessed by CVP

35
Q

What does standard V say regarding temperature?

A

“Monitor body temperature continuously on all peds pts receiving GA and when indicated on all other pts.”

36
Q

Why is it important to monitor temp during GA?

A

Anesthetics inhibit central thermoregulation by interfering with hypothalamic function

  • during spinal/epidural anesthesia, hypothermia occurs secondarily to internal redistribution of heat
  • sympathetic blockade leads to vasodilation and peripheral pooling of blood
37
Q

Why is it important to monitor neuromuscular function?

A
  • when NMB agents use—> every person responds differently to paralytics
  • continuous monitoring guides dosing
    • residual paralysis in PACU causes significant complication
      • Suggamadex has greatly changed our practice
38
Q

Which nerves to we use with the nerve stimulator/TOF and which muscles do they involve?

A
  • ulnar nerve: causes contraction of adductor pollicis muscle
  • facial nerve: causes contraction of obicularis occuli muscle
39
Q

Which of the nerves used in the TOF recovers from NMB quickest?

A

Obicularis occuli

40
Q

In the TOF, what happens during a fade?

A

The strength of twitches decreases over the set of 4

Millivoltz: try to get a baseline, if not, use best judgement

41
Q

What percent of receptors are blocked when you start to lose twitches with the nerve stimulator?

A

~70%

* even 4/4 twitches may still have 70% of receptors blocked *

42
Q

Other than TOF, what are the other settings on a nerve stimulator?

A
  • Double burst: 2 shocks (2 twitches)

- Tetany: continual shock (continual muscle contraction)

43
Q

What will you see during induction and with nerve stimulator in non-depolarizers (Roc and Vec)?

A

No myoclonus

Will have a fade

44
Q

What will you see during induction and with the nerve stimulator in depolarizers (Succ)?

A
  • Myoclonus * (contraction then relaxation)
  • no fade- all twitches will be of same strength
    • height may decrease the next time tested- still all four of those twitches will be of equal height to each other
45
Q

What happens if you stimulate tetany on nerve stimulator, followed by TOF?

A

Release of acetylcholine—> next stimulus may elicit twitches

- indicates paralytic will start wearing off soon

46
Q

What is true about a pt in the prone position?

A

Prone pts don’t pee a lot

47
Q

What is considered oliguria, and when is using a foley indicated?

A
  • UOP < 0.5mL/kg/hr
  • CHF
  • renal failure
  • shock
  • surgery with large fluid shift expected
  • intra operative diuretics
48
Q

What info does having a Foley in place give you?

A

Indicator of renal, CV and fluid volume status

49
Q

What is useful regarding EEG?

A

Provides early evidence of cerebral ischemia in carotid endarterectomy and cardio pulmonary bypass

  • monitors depth of anesthesia
    • EEG activity decreases with GA
50
Q

What is an evoked potential (EP)?

A

Electrical manifestation of brain’s response to external stimulus

 - used when potential for neuro. Injury is present
      - spinal fusion 
      - craniotomy
51
Q

Evoked potential (EP) non-invasively assesses neuro function by measuring EP in response to:

A
  • visually evoked potentials (VEP)
  • auditory evoked potentials (AEP)
  • somatosensory evoked potentials (SEP)
  • motor evoked potentials (MEP)
52
Q

What does a BIS <60 indicate?

A

High probability of unresponsiveness during surgery/low probability of awareness
* want no lower than 40 *

53
Q

What do the following BIS scores correlate with in terms of consciousness: 0, 20, 40, 60, 80, 100?

A

0: flatline EEG
20: burst suppression
40: deep hypnotic sleep
60: GA (general anesthesia)
80: light moderate sedation
100: awake

54
Q

What is an INVOS and what is it used for?

A

Non-invasive cerebral oximetry

  • measures site specific O2 levels
  • important when clamping carotid artery
  • get baseline, base treatment on changes from baseline
  • 2 large stickers placed on forehead