Equipment, Instrumentation & Technique

Question 1

Which type of visual evoked potential is performed on an awake patient?

Answer 1

Patterned VEPs
During Visual Evoked Potentials (VEPs), the patient is presented a visual stimulus for a select number of times, then the cerebral responses are dispayed after being amplified and averaged on a computer. There are two types of VEPs: patterned and unpatterned. Patterned tests are used on awake patients.

Question 2

Which of the following side effects is most likely to occur with the use of intraoperative blood salvage (cell saver)?

Answer 2

air embolism
The most common side effects of intraoperative blood salvage are air embolism, abnormalities in coagulation, and DIC-like syndrome (also known as salvaged-blood syndrome).

Question 3

Which airway device is tolerated more easily in awake patients?

Answer 3

nasal airways
Nasal airways are made of soft rubber and are tolerated better than oral airways in awake patients. Oral airways are made of hard plastic and are positioned at the base of the tongue and posterior pharynx.

Question 4

Which gases exists in a liquid state in a pressurized cylinder? (select two)

Answer 4

Nitrous oxide and carbon dioxide both exist in a liquid state in a pressurized cylinder.

Question 5

Tetanic fade is a response to blocking which type of receptor?

Answer 5

Presynaptic nicotinic acetylcholine receptors

Tetanic fade occurs due to blockade of presynaptic nicotinic acetylcholine receptors.

Question 6

What is the ideal location of an esophageal temperature probe?

Answer 6

In the lower third of the esophagus
Ideally, it should be placed in the lower third of the esophagus which positions it between the heart and the descending aorta. In this position, it is most resistant to the temperature effects of gases traveling through the trachea.

Question 7

Which of the following devices offers the most resistance to breathing?

Answer 7

A 7.5 mm endotracheal tube
Resistance to gas flow is a function of the length of the tube and its diameter. The shorter the length and the larger the diameter, the less resistance it offers. Of these items, the endotracheal tube offers the greatest amount of resistance to gas flow.

Question 8

Which evoked potential is useful in evaluating descending motor pathways?

Answer 8

Motor evoked potential

MEP assesses descending motor pathways while BAEP, SSEP, and VEP give data about ascending sensory neural pathways.

Question 9

What size laryngeal mask airway (LMA) would be appropriate for a 15 year-old female who weighs 142 pounds?

Answer 9

4
The LMA comes in several sizes: 1 for infants less than 5 kg, 1.5 for 5-10 kg, 2 for children 10-20 kg, 2.5 for children 20-30 kg, 3 for children and small adults between 30-50 kg, 4 for 50-70 kg, 5 for 70-100 kg, and 6 for patients greater than 100 kg. This patient weighs 142 pounds which equals 64.5 kg.

Question 10

Which of the following agents are least likely to alter the latency or amplitude of somatosensory evoked potentials? (select two)

Answer 10

Ketamine & Etomidate
Most anesthetic agents will alter the latency or amplitude of somatosensory evoked potentials except for opioids, ketamine, and etomidate.

Question 11

Rank the order in which the structures would exhibit paralysis after administration of a neuromuscular blocking agent.
eye muscle
abdominal muscles
diaphragm 
extremities

Answer 11

Eye muscles are the first to be paralyzed, the extremities are affected next, followed by the trunk, abdominal muscles, and lastly, the diaphragm. Recovery is restored in reverse order.

Question 12

The low peak pressure alarm is activated when

Answer 12

The low peak pressure alarm is activated when the ventilator is turned on. It is designed to help detect disconnects in the anesthesia circuit. In order to prevent the alarm from triggering, the airway pressure must exceed a preset minimum within a set amount of time (usually about 15 seconds).

Question 13

The anesthesia machine fail-safe mechanism will

Answer 13

The oxygen fail-safe device will trigger an alarm and shut off the supply of nitrous oxide in the event of loss of oxygen supply pressure.

Question 14

When is use of the oxygen flush control valve contraindicated in a mechanically-ventilated patient?

Answer 14

During inspiration
The oxygen flush control valve delivers oxygen at a rate of 35-75 L/min and a pressure of 50 psi. To avoid barotrauma, it should never be used when there is no outlet for excess gas pressure to escape. This situation exists when the patient is in the inspiratory phase of mechanical ventilation when the inspiratory valve is open to the patient but there is no vent for gases to escape.

Question 15

The infusion of one liter of crystalloid at room temperature or one unit of refrigerated blood will decrease mean body temperature by approximately

Answer 15

0.25 degrees Celsius
For every one unit of refrigerated blood or liter of room temperature crystalloid infused, mean body temperature decreases by 0.25 degrees Celsius (about 0.45 degrees Fahrenheit).

Question 16

What internal diameter cuffed endotracheal tube would be appropriate for a full-term infant?

Answer 16

3.0 mm
For a full-term infant, a 3.0 cuffed endotracheal tube would be appropriate. Uncuffed 2.5-3.0 tubes are recommended for premature infants.

Question 17

Match the gas cylinder contents with the corresponding tank color standard used in the United States.
O2
Air
Co2
nitrous oxide

Answer 17

Oxygen cylinders are green, nitrous oxide cylinders are blue, carbon dioxide cylinders are gray, air cylinders are yellow, nitrogen cylinders are black, and helium cylinders are brown. These colors can vary outside of the United States.

Question 18

You have placed an arterial line in a patient’s radial artery and are preparing to zero the system. The tranducing system should be placed level with

Answer 18

atria
When an arterial transducer system is zeroed to atmospheric pressure, it should be level with the atria. The exception would be if you wanted to more closely monitor the cerebral perfusion pressure in which you would place it level with the ear.

Question 19

What substances could be misinterpreted by an infrared gas monitor as a volatile anesthetic? (select two)

Answer 19

Ethanol & Acetone
Infrared gas monitors are small and portable, they have a quick response time, a short warm-up time, and do not need to be connected to a scavenger because the analyzed gases can be returned to the circuit. Argon and nitric oxide don’t interfere with readings, but other substances such as ethanol, ether, paraldehyde, and acetone can be incorrectly detected as volatile agents. Although the response time is fast, it may not be fast enough to accurately analyze volatile agent levels if the respiratory rate is very high. Handheld two-way radios may interfere with the analyzer causing CO2 readings to be falsely elevated.

Question 20

What are the most common anatomical sites for invasive arterial monitoring line placement? (select two)

Answer 20

radial & Femoral
Although many arterial sites can be used (including brachial, axillary, and dorsalis pedis), the most commonly used are the radial and femoral sites.

Question 21

During nasotracheal intubation, the tracheal tube should be inserted into the nares

Answer 21

perpendicular to the face
When performing a nasotracheal intubation, the tracheal tube should be inserted into the nares at an angle perpendicular to the face with the bevel directed away from the turbinates.

Question 22

Which of the following endotracheal tubes has been shown to be more effective in preventing early postoperative pneumonia?

Answer 22

Polyurethane endotracheal tube
Studies show that endotracheal tubes with a polyurethane cuff have a decreased association with early postoperative pneumonia.

Question 23

What is the maximum cuff volume for a size 4 LMA?

Answer 23

30mL
The maximum cuff volumes for LMAs by size are: size 1: 4 mL, size 1.5: 7 mL, size 2: 10 mL, size 2.5: 14 mL, size 3: 20 mL, size 4: 30 mL, size 5: 40 mL, size 6: 50 mL.

Question 24

Which laryngoscope blade has a handle-operated, articulating tip designed to elevate the vallecula and epiglottis?

Answer 24

McCoy
The McCoy blade has a handle-operated, articulating tip designed to elevate the vallecula and epiglottis. The Soper blade is a straight blade with a left-facing flange that makes it a blend between the Miller and Macintosh blades.

Question 25

Match the peripheral nerve monitoring setting with its characteristic.

Answer 25

Double-burst stimulation (DBS) is characterized by two short sequences of 50 Hz electrical impulses separated by 750 milliseconds. The primary use for DBS is to detect residual blockade by a nondepolarizing neuromuscular relaxant. Fade on the second burst of DBS is easier to detect than fade on a train of four. Tetanus consists of repeated electrical impulses at a rapid frequency of 50, 100, or even 200 Hertz. In the case of a depolarizing block, the amplitude of the contraction is decreased and fade is exhibited over the course of the five-second recommended duration of stimulus. A train-of-four stimulus consists of four single pulses of equal intensity at intervals of 0.5 seconds. When a partial depolarizing block is present, all four contractions will be diminished while in a partial nondepolarizing block, there will be a fade in intensity of the contraction over the course of the stimulations, with the potential absence of some or all of the contractions depending on the intensity of the block.

Question 26

On an anesthesia machine, what components are found in the intermediate pressure system? (select four)

Answer 26

A. Pipeline inlet connections
C. Oxygen flush valve
E. Flow control valves
F. Pipeline pressure indicators
The intermediate pressure system of an anesthesia machine contains the pneumatic part of the master switch, pipeline inlet connections and pressure indicators, the gas power outlet, oxygen flush valve, oxygen pressure failure devices, and flow control valves.

Question 27

A pulse oximeter alarms that a patient’s saturation has dropped below the alarm threshold. This is an example of what type of an alarm?

Answer 27

Unlatched
A pulse oximeter alarm is an example of an unlatched alarm. Unlatched alarms sound only as long as the criteria (in this case a saturation threshold) for sounding are met. If the patient’s saturation rises above threshold, the alarm will quit sounding on its own. Once triggered, a latched alarm will sound until it is silenced by interaction with the monitor.

Question 28

What effect will volatile anesthetics have on somatosensory evoked potential (SSEP) monitoring?

Answer 28

They will increase latency and decrease the amplitude of the SSEPs
Volatile anesthetics increase the latency and decrease the amplitude of SSEPs in a dose-dependent fashion.

Question 29

Which of the following has been demonstrated to affect the accuracy of non-invasive blood pressure monitoring?

Answer 29

arm position
If the NIBP cuff is not level with the heart, then a correction must be made to compensate for the difference between arm and systemic pressure. For every 10 cm the cuff is above the level of the heart, you must add 7.5 mm Hg to estimate the systemic pressure accurately. Likewise, for every 10 cm the NIBP cuff is below the level of the heart, you must subtract 7.5 mm Hg to correctly estimate the systemic pressure.

Question 30

Which of the following represents the ideal position for the respirometer?

Answer 30

On the CO2 absorber
A Wright respirometer is located in the expiratory limb and contains vanes that cause it to rotate when exhaled gas passes across it. If the respirometer is positioned close to the patient, then a proximal circuit disconnection may go unnoticed because it would still register tidal volume. This is unlikely to happen if the respirometer is positioned on the CO2 absorber.

Question 31

Which of the following is true regarding flowmeter indicators?

Answer 31

Ball-shaped floats should be read at the middle of the indicator
If using a bobbin, the flow rate should be read at the top of the indicator. When using a ball-shaped float, the flow rate should be read at the middle of the ball.

Question 32

What ventilator modality is described by a setting that has a target gas delivery pressure and where the tidal volume varies from breath to breath depending upon the patient’s resistance and compliance?

Answer 32

pressure-controlled ventilation
With pressure controlled ventilation, there is a target gas delivery pressure established. Tidal volume varies from breath to breath depending upon the patient’s resistance and compliance. At the beginning of inspiration, the ventilator rapidly increases the pressure to the determined level and maintains that pressure until the beginning of exhalation.

Question 33

Disadvantages of using a heat and moisture exchanger (HME) include (select two)

Answer 33

Increased work of breathing & Can result in airway obstruction
Heat and moisture exchangers (HME) are inexpensive, silent, easy-to-use devices that help retain heat and moisture within the anesthesia circuit. Advantages of HMEs include: no need for water or electrical power source and no risk of hyperthermia overhydration, burns, or electrical shock. They all act as large particle filters and many serve as effective bacterial and viral filters. The primary disadvantages of HMEs are that they are not nearly as effective at warming and humidifying the patient airway as water-based, electrical devices. They also increase deadspace and can increase the work of breathing. Airway obstruction can occur if the HME becomes blocked with fluid, blood, secretions, nebulized drugs, or if a mechanical defect is present in the device. If increased airway resistance is experienced during an anesthetic, the peak pressure should be measured both with and without the HME in place.

Question 34

You are connecting a nebulizer to an anesthesia circuit. The nebulizer should be placed

Answer 34

between the heat and moisture exchanger and the endotracheal tube
Nebulizers and metered-dose inhalers should be placed between the HME and the patient during treatment.

Question 35

The oxygen flush valve delivers up to _____ L/min.

Answer 35

75

Actuation of the oxygen flush valve delivers 100 percent oxygen at a flow of 35 to 75 L/min to the breathing circuit.

Question 36

Which of the following EEG changes would most likely be seen during periods of circulatory compromise to the brain?

Answer 36

Low frequency, high voltage activity
Cerebral compromise and deep anesthesia would typically display low frequency, high voltage EEG activity whereas surgical stimulation or light anesthesia would display high frequency, low voltage activity

Question 37

What is the approximate FiO2 delivered by a nasal cannula at a flow rate of 4 L/min?

Answer 37

0.36
The FiO2 delivered by a nasal cannula can vary significantly, but the ranges you can predict that would be delivered by varying flow rates are: 2L/min: 0.26 and 4L/min: 0.36

Question 38

You are administering anesthesia using a circle system. The fresh gas flow rate is 6 liters per minute and the patient’s minute volume is 4 liters per minute. This would be an example of

Answer 38

a semi-open circuit
Anesthesia circuits are classified based on whether or not they have a reservoir bag and the degree to which rebreathing of gases occurs.  The four major classes of circuits are open, semi-open, semi-closed, and closed.  Depending on fresh gas flow rates, a circuit can change classes.  For example, in both the nonrebreathing circuits and circle system, the circuit is considered semi-open if the fresh gas flow rate is greater than the minute ventilation.  If the fresh gas flow rate is less than the minute ventilation, then the patient must be rebreathing some of the exhaled gases and the circuit class is considered semi-closed.

Question 39

Click the Exhibit button at the top of the screen. Depicted in the exhibit are the reactions that occur in soda lime when exposed to carbon dioxide. What item should appear at the location labeled X to complete the equation?

Answer 39

The slow reaction that takes place within the soda lime absorber is: Na2CO3 + Ca(OH)2 -> CaCO3 + 2 NaOH. The easiest way to finish the equation is to write down how many atoms of each element appear on the left side of the equation and how many atoms of each element appear on the right side of the equation. Subtract the ones on the right from the ones on the left. Whatever atoms are left over must form the remaining portion of the balanced equation.

Question 40

In the event of an oxygen supply failure, the oxygen fail-safe device on an anesthesia machine will

Answer 40

turn off the nitrous oxide supply
The oxygen fail-safe device will trigger an alarm and shut off the supply of nitrous oxide in the event of loss of oxygen supply pressure.

Question 41

Which of the following statements regarding the use of a first generation laryngeal mask airway (LMA) is true?

Answer 41

The presence of a pharyngeal abscess is a contraindication to its use
A first generation LMA doesn’t protect against gastric secretions. Ventilation requiring pressures in excess of 20 cm H2O may result in inflation of the stomach. It can become malpositioned, resulting in an inability to ventilate. It is contraindicated in pharyngeal pathology such as tumor or abscess. Pathology at or below the level of the LMA may make it an ineffective means of ventilation.

Question 42

The two principal components of evoked potential monitoring are

Answer 42

amplitude and latenyc
Evoked potential waveforms have two major parameters that are observed: amplitude and latency. The amplitude is measured in microvolts (millivolts for motor evoked potentials) and is represented by the height of a waveform relative to the baseline voltage. Amplitude is a measurement of the intensity of the response to the signal. Latency is measured in milliseconds and represents the delay in the response to the stimulus. The latency indicates how long it takes for the signal and response to travel along the neural pathyway.

Question 43

Which is the most important component of the scavenging system?

Answer 43

Scavenging interface
The scavenging interface is the most important component of the system because it protects the breathing circuit or ventilator from excessive positive or negative pressures.

Question 44

Which factor is most likely to result in an overestimation of the oxygen saturation?

Answer 44

anemia
The accuracy of an SpO2 monitor can be adversely affected by pathologic hemoglobin forms (carboxyhemoglobin, methemoglobin), intravenous dyes (methylene blue, indigo carmine), motion artifact, nail polish, ambient light, and even electrocautery. Anemia can result in an overestimation of the oxygen saturation. Optical interference caused by ambient lights flickering at a frequency similar to the pulse oximeter LED can cause erratic readings. Nail polish and intravenous dyes can result in an underestimation of the oxygen saturation.

Question 45

Some ECG monitors are able to measure respiratory rate and depth using the principle of

Answer 45

impedance plethysmography
By using a technique called impedance plethysmography, the ECG is able to measure the electrical impedance of the thorax through the ECG electrodes. As the patient inspires, the lungs fill with air and increase the electrical impedance of the thorax. As the patient exhales, the impedance decreases. This change in impedance is referred to as Delta-Z and provides a waveform that allows the anesthetist to evaluate the depth of respiration as well as rate. ECG lead I evaluates upper chest breaths while lead II evaluates the lower chest and diaphragm. It is most commonly used in spontaneously breathing patients in PACU or ICU.

Question 46

Which of the following statements is true regarding surgical lasers? (select two)

Answer 46

The laser light must be absorbed for it to be effective & Different tissues are affected by different laser wavelengths
Laser light has to be absorbed for it to be effective. If the light is reflected or scattered, it will be ineffective. Different tissues are affected by different laser wavelengths. The wavelength of the laser must match the absorptive characteristic of the tissue. Once absorbed, the laser light converts to heat within the tissue. If the amount of heat generated reaches 100 degrees Celsius, the tissue will be vaporized.

Question 47

What CVP waveform changes would you expect to see in a patient with atrial fibrillation? (select two)

Answer 47

Absent A waves & Prominent C waves

Atrial fibrillation can result in absent A waves and prominent C waves on the CVP waveform.

Question 48

An E-cylinder oxygen tank pressure gauge reads 950 psig. How much oxygen is left in the tank? Provide your answer in liters to the nearest whole number.

Answer 48

330
A full E-cylinder oxygen tank holds 660 liters at a pressure of 1900 psig. Because an oxygen tank’s pressure is proportional to its contents, if the pressure falls by half, then the number of liters falls by half as well.

Question 49

At 760 mmHg, the boiling point of Desflurane in degrees Celsius is:

Answer 49

22.8
At standard pressure, the boiling points for inhalation anesthetics in degrees Celsius are: Desflurane-22.8, Isoflurane-48.5, Halothane-50.2, Enflurane-56.5, and Sevoflurane-58.5.

Question 50

What does the y descent on a central venous pressure waveform represent?

Answer 50

Opening of the tricuspid valve
There are three descents that appear on the central venous pressure waveform. The x descent follows the a wave and represents the relaxation of the atria. The x1 descent occurs as a result of the downward pull of the ventricular septum during systole. The y descent represents the opening of the tricuspid valve.