Anesthesia MONITORING DEVICES | Part I Flashcards
The main value of monitoring central venous and right-heart pressures lies in their ability to approximate or trend in conjunction with the ___
A. left ventricular end-diastolic pressure (LVEDP)
B. pulmonary circulation
C. cardiac output
A. left ventricular end-diastolic pressure (LVEDP)
The CVP is equivalent to right atrial pressure and serve as reflection of:
A. right ventricular preload
B. right atrial pressure
C. left ventricular preload
A. right ventricular preload
The CVP is essentially equivalent to right atrial pressure and serves as a reflection of right ventricular preload
Which wave of the CVP is absent in a patient with Atrial Fibrillation?
A. a wave
B. x descent
C. y descent
A. a wave
Based of POCUS, a full stomach is presence of solid contents or a gastric fluid volume of:
A. >1.5mL/kg
B. > 1mL/kg
C. >2.5 mL/kg
A. >1.5mL/kg
In most studies, the presence of solid contents, or gastric fluid volume >1.5 mL/kg, is defined as “full stomach.”
When performing POCUS of the lung, at least how many areas must be scanned for an optimum assessment?
A. at least 3 areas of the lung
B. at least 2 areas of the lung
C. one area from the apex and one area from the base is acceptable
A. at least 3 areas of the lung
Lung ultrasound can be performed with linear, phased array or curvilinear probes, depending on the patient’s body habitus.
At least three areas must be examined in each patient: anteriorly below the clavicle, anterolaterally in fourth to fifth intercostal space, and posterolaterally in the
seventh to ninth intercostal space.
Which of the following is considered an ABSOLUTE contraindication of TEE?
A. Previous radiation therapy to the neck or mediastinum
B. History of upper GI hemorrhage
C. Esophageal varices
D. Active gastric ulceration
E. Gastroesophageal strictures
E. Gastroesophageal strictures
What is the normal PVR:
A. 100–300 dyne-cm-sec−5
B. 50–150 dyne-cm-sec-5
C. 300 - 450 dyne-cm-sec-5
A. 100–300 dyne-cm-sec−5
What is the normal FRC?
A. 2.4L
B. 1.5L
C. 2L
A. 2.4L
Which is the most sensitive test to diagnose an air embolism?
A. TEE
B. TTE
C. CVP
A. TEE
TEE is most sensitive
‘cannon waves’ seen on CVP waves is most likely due to which pathology?
A. Mitral stenosis
B. Tricuspic stenosis
C. Aortic stenosis
B. Tricuspic stenosis
Which of ECG lead provides the highest sensitivity for monitoring of ischemia?
A. Lead II
B. V5
C. Lead I
D. V2
B. V5
Usually, lead II is monitored for inferior wall ischemia and
arrhythmias, and V5 is monitored for anterior wall ischemia. When only one lead can be monitored, a modified V5 lead provides the greatest sensitivity.
Which of the following is INACCURATE when peripheral nerve stimulator is used for NMB monitoring?
A. The electrode placement should be oriented with the negative electrode more PROXIMAL and the positive electrode more DISTAL.
B. It usually deliver a square wave current of 10 to 80 mA for 100 to 300 microseconds (greater than 300 microseconds may exceed the nerve refractory period).
C. Quantitative monitoring is the only way to objectively measure train-of four ratio.
D. TOF should not be repeated more frequently than every 15 seconds to avoid potentiation or muscle contraction
exaggeration.
A. The electrode placement should be oriented with the negative electrode more PROXIMAL and the positive electrode more DISTAL - **False statement **
Electrode placement should be oriented with the negative electrode more distal (usually black) and the positive electrode more proximal (sometimes red, “red toward the head”).
Rule of thumb:
NEGATIVE - more DISTAL
**POSITIVE - more PROXIMAL **
Which of the following is most effective in decontaminating an anesthesia machine that was splattered with HIV-contaminated blood?
(A) Bleach
(B) Deionized water
(C) Ethylene oxide
(D) Hydrogen peroxide
(E) Isopropyl alcohol
(A) Bleach
Each of the following factors may lead to erroneous readings using pulse oximetry EXCEPT:
(A) electrocautery
(B) high cardiac output states
(C) infrared lights near the sensor
(D) intravenous dyes
(E) severe hemodilution
(B) high cardiac output states
TRUE or FALSE
Desflurane is an inhalational anesthetic agent that has a high vapor pressure and must be stored in a heated, pressurized vaporizer.
TRUE
TEC 6 is HEATED and PRESSURIZED
Which of the following is accurately paired when employing nerve stimulators?
A. Ulnar nerve: Abductor polliccis
B. Facial nerve: Corrugator supercilli
C. Ophthalmic branch of Trigeminal: Corrugator supercilli
D. Radial nerve: Adductor polliccis
B. Facial nerve: Corrugator supercilli
Rule of thumb:
ADDUCTOR is ULNAR
CORRUGATOR is FACIAL
According to BARASH, Residual paralysis is currently defined as a train-of-four ratio less than:
A. 0.7
B. 0.9
C. 0.4
B. 0.9
Regression of drug during NMB reversal will chronologically follow this pattern:
A. T1 return first followed by T2, T3, lastly T4
B. T4 return first followed by T3, T2, lastly T1
C. T4 return first then T1, T2, lastly T3
- As the effects of a nondepolarizing neuromuscular blocking drug deepen, the number of muscle responses will decline, T4 will be lost first, then T3, then T2 and finally T1.
- Regression of drug effect (i.e., during recovery) will follow the same pattern in reverse, where T1 will return first
followed by T2, then T3, and finally T4.
Rule of thumb:
Blocking = T4 > T3 > T2> T1
Regression = T1> T2> T3 > T4
In terms of variability, which of the following is MOST SENSITIVE to muscle blockade?
A. Diaphragm
B. Corrugator supercilii
C. Adductor pollicis
D. Orbicularis oris
C. Adductor pollicis
Variability in muscle blockade (most resistant TO most sensitive):
vocal cords > diaphragm > corrugator supercilii > abdominal muscles > adductor pollicis > pharyngeal muscles
- most sensitive = pharyngeal muscles
- most resistant = vocal cord
To assess return of function of pharyngeal muscles (i.e. readiness for extubation): monitor adductor pollicis*
Which of the following conditions can potentially INCREASE the spO2 reading in pulse oximetry?
A. Hypotension – decrease
B. Anemia – decrease
C. Polycythemia – No effect
D. Carboxyhemoglobinemia
D. Carboxyhemoglobinemia
What is the MOST plausible explanation for the given capnograph above?
A. presence of a leak in a sidestream sample line
B. cardiogenic oscillations at the end of exhalation
C. rebreathing of CO2
D. faulty inspiratory valve
B. cardiogenic oscillations at the end of exhalation
- Which labeled point is the best reflection of alveolar CO2 partial pressure?
A. A
B. B
C. C
D. D
E. E
POINT D
RATIONALE:
Point D is the end-tidal CO2 (E CO2), which best reflects PaCO2.
A-B is phase I of expiration and reflects anatomic dead space.
B-C is phase II of expiration and reflects a mixture of both dead space and alveolar gas.
C-D is phase III of expiration (alveolar gas plateau) and reflects alveolar gas.
D-E is due to inspiration.
For most surgical patients, the most likely cause o perioperative heat loss is due to:
(A) radiation
(B) conduction
(C) convection
(D) evaporation
(A) radiation
Radiant heat transfer means that objects of higher temperature will radiate heat and objects of lower temperature will absorb heat. Radiation is the most significant cause of heat loss in most surgical patients.
Conductive heat transfer occurs when two surfaces with a temperature difference are in close contact. This usually accounts for minimal heat loss in the operating room.
Convective heat transfer occurs when air currents act to transfer heat from the patient to the environment. This is usually the second-most significant cause of heat loss in most surgical patients. Evaporative heat transfer from sweating (or surgical wounds) is significant or premature infants but usually not or adults.
A surgical procedure requires the strict avoidance of any sudden patient movement. Anesthetic includes large doses of a nondepolarizing neuromuscular blocking drug. Which method of electrical nerve stimulation is the best to monitor this degree of neuromuscular blockade?
(A) double burst stimulation
(B) train-of - four stimulation
(C) single-twitch stimulation
(D) tetanic stimulation
(E) post-tetanic count stimulation
(E) post-tetanic count stimulation
Auscultation of Korotkoff sounds allows or indirect measurement of arterial blood pressure. Which phase corresponds to systolic blood pressure?
(A) phase I
(B) phase II
(C) phase III
(D) phase IV
(E) phase V
(A) phase I
Which noninvasive method of determining oxygen saturation (SO2) can accurately measure methemoglobin (MetHb) concentrations?
(A) co-oximetry
(B) pulse co-oximetry
(C) pulse oximetry
(D) transcutaneous oximetry
(E) reflectance pulse oximetry
(B) pulse co-oximetry
Cyanosis is clinically apparent with this hemoglobin value?
A. 5 g/dL
B. 3 g/dL
C. 6 g/dL
D. 4 g/dL
A. 5 g/dL
Which of the following ECG placement is INACCURATELY paired?
A. V3: Midway between V2 and V4
B. V4: 5th ICS-MCL
C. V5: 5th ICS-MAL – 5th ICS-AAL is the correct anatomical placement
D. V6: 5th ICS-MAL
C. V5: 5th ICS-MAL – 5th ICS-AAL is the correct anatomical placement
READ
- The normal PR interval of a 70 kg ASA I adult is:
A. 0.12 – 0.20 secs
B. 0.10 – 0. 20 secs
C. 0.12 – 0.25 secs
D. 0.10 – 0.20 secs
A. 0.12 – 0.20 secs
The normal QT interval is:
A. <0.38 secs
B. <0.35 secs
C. <0.25 secs
D. <0.20 secs
A. <0.38 secs
What route of temperature monitoring will accurately approximate the core body temperature if pulmonary catheter is NOT available?
A. proximal esophagus
B. tympanic membrane
C. rectum
D. nasopharynx
A. proximal esophagus
Which of the following NMB monitoring modality is LEAST reliable when evaluating the recovery from neuromuscular blockade?
A. PTC
B. TOF count
C. Double burst stimulation
C. Double burst stimulation
What is the dose of sugammadex if the PTC (post-tetanic count) is 0?
A. 8mg/kg
B. 16mg/kg
C. 2mg/kg
D. 4mg/kg
B. 16mg/kg
Rule of thumb:
PTC 0 —— 16mg/kg
PTC 1-2 —– 4mg/kg
TOF count 1-2 —- 2mg/kg
TOF count 4 — 1mg/kg
If the TOF count is 4, how long will it take to fully reverse the neuromuscular blockade with a SUGAMMADEX dose of 1 mg/kg?
A. 2 minutes
B. 1 minute
C. 4 minutes
D. 5 minutes
A. 2 minutes
High-yield notes:
If the TOF count is 4:
1mg/kg of SUGAMMADEX needs 2 minutes to fully recover!
0.5mg/kg of SUGAMMADEX needs 8 minutes to fully recover!
What is seen on EEG with high doses of opiates?
A. High amplitude delta waves
B. Low amplitude delta waves
A. High amplitude delta waves
TRUE or FALSE
The EEG signal is generated only by postsynaptic
potentials.
TRUE
The EEG is produced by a summation of excitatory and
inhibitory postsynaptic potentials produced in cortical gray
matter.
Because the EEG signal is generated only by postsynaptic
potentials and is much smaller than action potentials
recorded over nerves or from heart muscle, extreme care
must be taken when placing electrodes to ensure proper
placement and excellent contact with the skin to avoid significant signal loss.
Which of the following is INACCURATE regarding clinical application EEG?
A. EEG amplitude increases with age
B. The EEG is a surface recording of the summation of excitatory and inhibitory postsynaptic potentials
C. The EEG may be used to predict neurologic outcome after a brain insult
D. The EEG may be used to gauge the depth of the hypnotic state of the patient under general anesthesia
A. EEG amplitude increases with age - false statement!
- All the other statements are ACCURATE.
The EEG signal is described using three basic parameters: amplitude, frequency, and time. Amplitude is the size, or voltage, of the recorded signal and ranges commonly from 5 to 500 μV (vs. 1-2 mV for the electrocardiogram signal).
Because neurons are irreversibly lost during the normal aging process, EEG amplitude decreases with age. Frequency can be thought of simply as the number of times per second the signal oscillates or crosses the zero voltage line.
Time is the duration of the sampling of the signal; this is continuous and real time in the standard paper or digital EEG, but is a sampling epoch in the processed EEG (see later).
Which is more effective in terms of defibrillation?
A. Monophasic
B. Biphasic
B. Biphasic
Rule of thumb:
- Biphasic is more effective.
- Monophasic uses more energy.
The standard definition of a fully recovered neuromuscular blockade in terms of TOF count and/or TOF ratio is?
A. TOF count of 4 or TOF ratio of 0.9 or higher
B. TOF count of 4 or TOF ratio of 0.7 or higher
C. TOF count of 3 or TOF ratio of 0.9 or higher
D. TOF count of 3 or TOF ratio of 0.7 or higher
The most important level of block is “recovered,” where the train-of-four count is 4 and the train-of-four ratio is ≥0.9.
What is the TOF ratio that clinically correlates with a 5-second head lift?
A. 0.60
B. 0.95
C. 0.70
A. 0.60
What is the TOF ratio that clinically correlates when there is already an ability to oppose incisors against a tongue depressor?
A. 0.85
B. 0.95
C. 0.70
D. 0.50
A. 0.85
One of the maneuver to improve the electrical stimulus transfer to the nerve when nerve stimulator is employed is cleansing the skin with alcohol and abrading with gauze. This will reduce the skin resistance to:
A. <5,000 Ohms
B. <10,000 Ohms
C. <3,000 Ohms
A. <5,000 Ohms
To further improve electrical stimulus transfer to the nerve, proper skin preparation, including cleansing with alcohol and abrading with gauze, will reduce skin resistance (from 100,000 Ohms to <5,000 Ohms).
After intubating a 20 y.old ASA I patient, you noticed that the value of your TOF count is 0 and PTC(post-tetanic count) >1. Qualitatively, this is considered as:
A. Deep blockade
B. Complete blockade
C. Moderate blockade
D. Shallow blockade
A. Deep blockade
PTC 0 Complete blockade
PTC >1 Deep blockade
Moderate depth of blockade corresponds to a TOF count of 1-3. What is the estimated receptor occupancy when moderate blockade is achieved?
A. 50 - 60%
B. 70 - 90%
C. 40 - 60%
B. 70 - 90%
Differentiate PHASE I versus PHASE II block?
Capnometery is LEAST useful for monitoring in which of the following:
A. Accidental extubation
B. Complete airway obstruction
C. Endobronchial intubation
D. Malignant hyperthermia
E. Esophageal intubation
C. Endobronchial intubation
Endobronchial intubation is not reliably detected by capnometry. Although one might be able to recognize changes in the CO2 waveform with one-lung ventilation, CO2 will continue to be detected by capnometry, and given the speed with which CO2 diffuses from blood to alveolar gas in normal lungs, the value will likely remain relatively constant, even with only one lung ventilated.
Hypoxia and increased airway pressures are more likely to be signs of endobronchial intubation.
Dr. Asum is planning to extubate his patient after an uneventful MRM however the only reversal agent available is ENDROPHONIUM. The quantitative monitoring revealed a TOF ratio of 0.5. What is the recommended dose he is allowed to give as a reversal agent?
A. 0.5mg/kg
B. 1mg/kg
C. 1.5mg/kg
A. 0.5mg/kg
Dr. Rataban is planning to extubate his patient after an uneventful thyroidectomy under GETA - TIVA using Propofol. She considering a reversal agent before extubation. The nerve stimulator revealed a TOF count of 4 WITHOUT fade. According to BARASH, what is the recommended dose of drug for her patient’s depth of blockade?
A. 30 mcg/kg of Neostigmine
B. 40 mcg/kg of Neostigmine
C. 10 mcg/kg of Neostigmine
D. 4 mg/kg of Sugammadex
A. 30 mcg/kg of Neostigmine
REMEMBER:
This is a TIVA case and the depth of blockade at this point is ‘MINIMAL’ which means, a lower dose of neostigmine is needed to achieve an acceptable recovery without pulmonary complications.
With FADE = 40 - 50 mcg/kg
Without FADE = 15 - 30 mcg/kg
This QUANTITATIVE monitoring device is a volumetric measurement of muscle contraction rather than a measurement of force:
A. Kinemyography (KMG)
B. Mechanomyography (MMG)
C. EMG
D. Double burst stimulation
A. Kinemyography (KMG)
Kinemyography (KMG) is a technology in which a strip
of isoelectric polymer material is placed in the space between the thumb and index finger and then deforms with thumb movement.
The measured movement represents a thumb range of motion rather than force.
