Question | Answer |
What are the 4 essential features of monitoring? | 1) Instrumentation
2) Observation and Vigilance
3) Interpretation
4) Intervention |
What is ASA Standard I? | Qualified personal must be present with patient at all times. |
What is ASA Standard II? | Must continually evaluate:
1) temp
2) oxygenation
3) ventilation
4) circulation |
Where are expired gases sampled from? | The Y piece of the ventilatory circuit |
What are 3 techniques for monitoring expired gases | 1) infrared spectrophotometry (IRAS)
2) mass spectrometry
3) raman scattering |
Name the gases which are measured during anesthetic administration. | 1) oxygen
2) CO2
3) N2O
3) inhaled agents |
Is MAC determined by inspiratory sampling or expiratory sampling? | Expiratory |
Name two molecules which can not be measured by IRAS | 1) oxygen
2) IA (they all look the same to the IRAS) |
What are the two wavelengths used for IRAS? | 1) 2600
2) 4300 |
Name the law which is used to calculate gases via IRAS. | Beer-Lambert Law |
Name the molecules which can be sampled via Raman scattering. | 1) oxygen
2) H2O
3) CO2
3) N2O
4) inhaled agents
5) N2 |
Which alterations can be detected via CO2 monitoring? | 1) CO
2) ventilation
3) distribution of pulmonary blood flow
4) metabolic activity
5) equipment failures
6) ETT placement (not location) |
What is the gold standard for ETT verification and how is it done? | CO2 monitoring
3 "blips" of at least 30 mmHg with a return to 0 mmHg each time. |
Describe point A on capnogram. | beginning of expiration |
Describe region A to B on capnogram. | expiration of dead space contents. |
Describe region B to C on capnogram. | expiratory upstroke. |
Describe region C to D on capnogram. | plateau. |
Describe region D to E on capnogram. | inspiration. |
Which point is the number from capnometry obtained? | point D on capnogram. |
What will the upstroke on a capnogram look like for someone with obstructive lung disease? | Will be less vertical. "Shark fin" appearance. |
Which point on a capnogram is the best reflection of alveolar ventilation? | point D. |
What could be the problem if the baseline waveform of a capnogram does not return to 0? | 1) leak in an expiratory valve.
2) exhausted soda lime.
3) rebreathing of CO2 (low FGF).
4) deliberate addition of CO2 to FGF. |
What are 3 assumptions re: capnography? | 1) CO2 is easily diffusible
2) no V/Q mismatch
3) no sampling error |
During general anesthesia what is the "real correlation between PaCO2 and etCO2? | etCO2 is 5 to 10 mmHg less then the PaCO2. |
List 5 factors which decrease the accuracy of etCO2 monitoring. | 1) V/Q mismatch
2) gas sampling error
3) shallow tidal volumes
4) increase expiratory phases
5) uneven alveolar emptying |
What is the extreme example of V/Q mismatch called? | dead space ventilation (loss of perfusion with adequate ventilation) |
Name 4 diseases which would reduce the etCO2. | 1) PE
2) hypoperfusion states
3) reduced pulmonary blood flow
4) COPD |
Does etCO2 determine if the ETT is correctly placed in the trachea? | No. Only chest X-ray. |
When will etCO2 increase? | when CO2 production exceeds ventilation.
1) MH
2) increased muscle activity
3) bicarb administration (Le Chatlier's principle)
4) tourniquet release
5) breaking of bronchospasm
6) decreased MV. |
When will etCO2 decrease? | when ventilation exceeds CO2 production.
1) decreased muscle activity.
2) hypothermia.
3) PE
4) bronchospasm
5) increased MV. |
List the steps to analyzing etCO2 waveform. | 1) look at the y axis (is it normal height)
2) does the waveform return to 0 mmHg
3) look at the expiratory limb (is there a sharp upstroke)
4) look at the RR |
name the two types of oximetry monitoring and where they are done at. | 1) FiO2 monitoring (in the inspiratory limb before the inspiratory unidirectional valve.
2) pulse oximetry (at the patient) |
True or False, the oxygen analyzer ensures adequate arterial oxygenation. | False. The oxygen analyzer ensures that the patient does not receive a hypoxic mixture of gas. |
Name 3 types of oxygen analyzers. | 1) paramagnetic
2) galvanic
3) polarographic |
which electrolyte solution is used for galvanic oxygen analyzers? | KOH |
which electrolyte solution is used for polarographic oxygen analyzers? | KCL |
Polarographic oxygen analyzers is based on which law? | Faraday's Law. |
What physiological parameters does the pulse ox detect? | 1) pulse rate
2) oxygen saturation of hemoglobin
3) fluid status |
What location most accurately measures pulse ox? | right ear |
What will happen to CO during inspiration with positive pressure ventilation? | decrease |
What will happen to CO during inspiration with spontaneous ventilation? | increase |
Name the two technologies employed in pulse oximetry. | 1) plethysmography
2) spectrophotometry |
Which law does spectrophotometry employ for pulse oximetry? | Beer Lambert Law |
What is the Beer-Lambert Law? | A=ebc
Where A is absorbance (no units)
e is the molar absorbtivity
b is the path length of the sample - that is, the path length of the cuvette in which the sample is contained in cm
c is the conc, of the compound in solution in mol L-1 |
What are the two wave lengths used in pulse oximetry and which types of hemoglobin do they measure? | 660 nm = deoxyhemoglobin
940 nm = oxyhemoglobin |
How is the pulse oximetry result expressed? | As a percentage based off of the ratio of saturated Hb divided by the total Hb. (no units) |
What will the saturation on pulse ox read with increased methemoglobinemia? | 85% |
What will happen to the pulse ox value with increased carboxyhemoglobin? | Falsely elevated SpO2. |
What is the error range for pulse ox when SaO2 is 70 to 100 percent? | plus or minus 2 to 3% |
What is the error range for pulse ox when SaO2 is 50 to 70 percent? | plus or minus 3% |
What factors affect pulse oximetry readings? | Vital dyes
Methylene blue
Indigocarmine
False lows
Nail polish
Ambient light
Light emitting diode variability
Motion artifact
Background noise
Electrocautery
Low cardiac output
Anemia
Methemoglobin
Carboxyhemoglobin |
What is the relationship described by the oxyhemoglobin disassociation curve? | Defines the relationship of hemoglobin saturation and oxygen tension. |
What are the PaO2 values for SpO2 of 97%, 90%, 80%, and 70%? | SpO2 of 97% = PaO2 of 97
SpO2 of 90% = PaO2 of 60
SpO2 of 80% = PaO2 of 50
SpO2 of 70% = PaO2 of 40 |