Clinical Monitoring Flashcards
When is thermoregulation required?
It is not required for every patient, but if a change is anticipated, normothermia must be facilitated.
When is neuromuscular response assessment required?
When an NMBA has been given
Which AANA standard of care number deals with monitoring, evaluating, and documenting?
Standard IX (9)
What is the main difference between a technician and a clinician?
A clinician does not simply react. A clinician thinks proactively and uses all the monitors and skills in harmony to provide care.
What might be happening if your patient is turning red?
Increased CO2
What are the three assessment tools under Fundamental basis of monitoring?
- Inspection
- Auscultation
- Palpation
What are the Six items under Monitoring according to AANA?
- Ventilation
- Oxygenation.
- Cardiovascular Status
- Body temp.
- Neuromuscular Function/Status.
- Patient Positioning.
What MUST be monitored under oxygenation?
Continuous pulse oximetry and via clinical observation.
Which law of physics is the pulse oximeter based off of?
Beer Lambert’s Law
What are the basics of Beer Lambert’s Law?
Relates the absorption of light by a solute to its concentration and optical properties at a given light wavelength.
How does a pulse oximeter work?
Send two wavelengths:
660(red)
and
940(infrared). Passes through arterial bed. Wavelengths are received on the other side with a preprogrammed calibration curve to give a % concentration of oxyhemoglobin.
Which hemoglobin absorbs 940nm (infrared) light?
Oxyhemoglobin
Which hemoglobin absorbs 660nm (red) light?
Deoxyhemoglobin.
What are some reasons the SpO2 could give an inaccurate measurement?
Motion artifact. Cautery interference. Abnormal Hgb. Anemia. Methylene blue. Vasoconstriction. Hypothermia. Hypotension.
What is a good rule of thumb for estimating PaO2 at a given SpO2?
SpO2 of 70, 80, 90 is roughly a PaO2 of 40, 50, 60
When do you use Cont ETCO2 monitoring?
During controlled or assisted ventilation requiring airway support.
During moderate and deep sedation.
What could suprasternal retractions tell you about the patient?
If there is an upper airway blockage.
What is the indication for precordial/esophageal stethoscopes?
Provides cont auditory confirmation of ventilation
Which patient population do precordial stethoscopes primary get used?
Pediatrics
What does ETCO2 monitoring provide for intubated versus non-intubated patients?
Intubated= quality of ventilation.
Non-intubated= simply the presence of ventilation
What is pCO2 compared to ETCO2?
Arterial CO2 is normally 2-5 higher than ETCO2.
What are the two types of ETCO2 sampling designs?
Mainstream/non-diverting
and
Sidestream/diverting
How does sidestream/diverting ETCO2 sampling work?
Extra little tubing coming off circuit. Has constant suction to draw a continuous sample.
ETCO2 waveform has 4 or 5 different phases, what are they?
A- Inhalation. B- Inhalation stops and beginning of exhalation. C-Exhalation D-END TIDAL CO2 Measurmenet. E-beginning of next breath.
What does line A-B represent on capnography?
A-B represents baseline inspiration to beginning of expiration.
What should the CO2 value be for line A-B?
Zero/baseline
What does line C-D represent on capnography?
C-D represents exhalation upstroke. Mixture of deadspace and exhaled TV.
What does D represent on capnography?
End-tidal waveform
What would a shark-fin capnograph waveform represent?
Asthma, COPD, bronchospasm
What does the curare cleft tell you?
Curare cleft is a slight dip in the C-D line that represents the diaphragm “flopping”. Deeper the NMBA blockade, the more pronounced the cleft.
Will ETCO2 increase or decrease with better CO?
It will increase
What must the anesthetist do when changing agents and using a monochromatic infrared spectrometry?
Monitor must be re-programmed with the agent selected.
What is mass spectrometry?
Early form. Usually a separate room that multiple samples were sent to, then sent back to the OR room.
On an old AGM, where was the respirometer/ventimeter located?
On the expiratory limb to measure TV and MV
How often is blood pressure and HR recorded?
At least every 5 minutes
Normal Right atrial pressure?
1-8 (2-10)
Normal Right Ventricular pressure?
25/0(5)
Normal Pulmonary artery pressure?
25/10
Normal Pulmonary Artery Wedge Pressure?
6-12
Name three contraindications for TEE?
Recent gastric bypass
Esophageal varices
Esophageal masses
What is the primary way to avoid post op hypothermia?
Prevention
What type of medications are at highest risk for altering thermoregulation?
Anesthetic gases
What are the three main branches of thermoregulation?
Afferent sensing
Central regulation
Efferent response
Which part of the brain loses its thermoregulatory ability under general anesthesia?
Hypothalamus
In aortic stenosis, which factor is mostly effected- preload, afterload, heart rate, or contractility?
Afterload
Out of the following, which one does not cause decrease in SVR: hypethermia, hypovolemia, sepsis, anaphylactic shock
Hypovolemia
How big should a blood pressure cuff be in relation to extremity circumference?
40%
What is the name of the initial long upstroke in an arterial line waveform?
Anacrotic limb
Formula for SVR
[(MAP-CVP)/CO] x 80
What is the most common cause of an overdampened arterial waveform?
Bent arm/positioning
Which patients ALWAYS must have body temp monitored continuously during GA?
Pediatric patients and when indicated on all other patients.
Which types of surgery will have the most profound effect on thermoregulation?
Open abdomen/ bowel surgery
What thermoregulatory function is inhibited during GA?
Hypothalamus
How is thermoregulation impaired during spinal/epidural anesthesia?
Sympathetic blockade causes vasodilation with peripheral pooling of blood
Peripheral nerve stimulator has two electrodes, what are they?
Positive (red) proximal aspect of nerve.
and
Negative (Black) distal aspect of nerve
When should you obtain your first peripheral nerve stimulation assessment?
Prior to NMBA administration in order to have a baseline and watch for changes.
Which muscle is stimulated by the ulnar nerve?
Adductor pollicis muscle
Which muscle is stimulated by the facial nerve?
Orbicularis oculi
Name a depolarizing NMBA;
succinylcholine
Name a non-depolarizing NMBA:
all the -oniums
Which type of NMBA “sticks” open the receptor so that it cannot be repolarized?
Depolarizing NMBA
Ex: succinylcholine
Which type of NMBA stops depolarization from occuring?
Non-depolarizing NMBA.
Ex; -oniums
What is a train-of-four assessment?
4 individual twitches.
0.2msec long.
500msec apart.
What is considered a more accurate assessment than TOF, but isn’t commonly used?
Double-burst stimulation
What is post-tetanic stimulation?
TOF after tetany assessment
What is the biggest difference seen with TOF between Non-depolarizing and depolarizing NMBA?
Depolarizing NMBA you will NOT see Fade
What is a TOF ratio?
Gives the difference between the 1st twitch and the 4th twitch
With non-depolarizing NMBA, at what % receptor occupancy can there still be an intact TOF?
At 75% receptor occupancy
At what % is twitch height effected with non-depolarizing NMBA?
At 75%
What are Visual Evoked Potentials (VEP)?
Bright lights via glasses
What are Auditory Evoked Potentials (AEP)?
Headphones with loud/high pitched noises
Somatosensory Evoked Potentials (SSEP)?
Looking at the sensory side (afferent)
What are Motor Evoked Potential (MEP)?
Looking at the motor side (efferent)
Where do SSEPs stimulate?
At the extremity
Where do MEPs stimulate?
At the head/brain
What is optimal BIS value during anesthesia?
BIS near 60
What does a BIS value of 100 represent?
Awake
What does a BIS value of 0 represent?
Dead (not awake)
What does a BIS value of 20 represent?
Patient is in Burst suppression
What information does a NIRS monitor provide?
Measures oxygen supply vs oxygen demand within a specific region.
Measures tissue oxygen index as a ratio
What is important to do with NIRS monitor prior to GA?
Get a baseline NIRS value
