Apex hotspot and Images Flashcards
Click on the area where the needle is inserted during a right superior laryngeal nerve block.
Explanation:
There are 3 key airway blocks:
- Glossopharyngeal
- Superior laryngeal
- Transtracheal
To block the superior laryngeal nerve, local anesthetic is injected just below the border of the greater cornu of the hyoid bone.
1 mL of local anesthetic is injected outside of the thyrohyoid membrane.
2 mL are injected just beneath the thyrohyoid membrane.
Click on the corniculate cartilage.
You guys have seen this view hundreds of times. Even so, you’ve likely succumbed to one of the most common misteachings in anesthesia. You CANNOT see the arytenoids during laryngoscopy!
What you are actually seeing are the corniculate and cuneiform cartilages. The cuneiforms are lateral to the corniculates.
Click on the region of the skull where Larson’s maneuver is performed.
You may know this concept as the laryngospasm notch. Like it or not, the NCE likes to test your vocabulary.
There are times where you’ll have to know two or more words for the same thing. Believe it or not, we have 5 synonyms for pseudocholinesterase! Don’t worry, we’ll cover that in the neuromuscular blockers tutorial. For now, let’s get back to laryngospasm and Larson’s maneuver.
Match the lung volumes and capacities to the corresponding letters in the image.
Inspiratory reserve volume
Inspiratory capacity
Functional residual capacity
Vital capacity
A
B
C
D
Inspiratory reserve volume + A
Functional residual capacity + B
Inspiratory capacity + C
Vital capacity + D
Which ion belongs in the box with the question mark?
Chloride
CO2 is the by-product of aerobic respiration. It diffuses from the cells into the venous circulation and then diffuses into erythrocytes.
In the presence of carbonic anhydrase (inside the RBC), CO2 and H2O react to form H2CO3. Carbonic acid rapidly dissociates into H+ and HCO3-. The H+ is buffered by hemoglobin, and the HCO3- is transported to the plasma to function as a buffer.
Cl- is transported into the erythrocyte to maintain electroneutrality. This is known as the chloride or Hamburger shift.
Match each letter to its corresponding event on the pulmonary flow-volume loop.
expiration
residual volume
TLC
inspiration
Expiration + A
Inspiration + B
Total lung capacity + C
Residual volume + D
A patient with COPD is mechanically ventilated. Which interventions will improve this patient’s condition? (Select 2.)
Decrease respiratory rate.
Disconnect the circuit.
Increase inspiratory flow.
Increase inspiratory time.
Decrease respiratory rate
Disconnect the circuit
The airway pressure in this waveform clearly depicts dynamic hyperinflation, otherwise known as breath stacking. Patients with COPD have a longer expiratory time constant, and this means they require a longer period of time to exhale fully.
Of the answer choices provided, there are two options that reverse dynamic hyperinflation. By reducing the respiratory rate, the patient will spend more time over the course of a minute in E time. If PEEP becomes dangerously elevated, the definitive treatment for dynamic hyperinflation is to remove the patient from the ventilator.
Increasing inspiratory time is another way of saying reducing expiratory time, so this choice will actually make the patient’s condition worse. The inspiratory flow determines how fast the tidal volume is delivered to the patient. Increasing the inspiratory flow will deliver the preset tidal volume faster, and this does nothing to facilitate expiration.
What is the first line treatment for this patient?
Pericardiocentesis
Cardiopulmonary resuscitation
14g angiocath insertion at the 2nd intercostal space midclavicular line
Chest tube insertion
14g angiocath insertion at the 2nd intercostal space midclavicular line
Emergency treatment of a tension pneumothorax includes insertion of a 14g angiocath into the 2nd intercostal space at the mid-clavicular line or the 4th or 5th intercostal space at the anterior axillary line. This will release the tension and relieve hemodynamic instability, but not the underlying pneumothorax.
Chest tube insertion is the definitive treatment. Pericardiocentesis is a treatment for pericardial tamponade. CPR should not be started based on a CXR alone.
Click on the tonsillar pillars. (Select 2.)
By measuring the size of the tongue relative to the volume of the mouth, the Mallampati exam helps us predict the difficulty of endotracheal intubation.
To perform the exam, the patient should:
Sit upright
Extend the neck
Open the mouth as wide as possible
Stick out the tongue
NOT phonate
This patient has a class I airway, because you can visualize the tonsillar pillars.
What is this patient’s mandibular protrusion test classification?
(Enter a number)
Class 3
The mandibular protrusion test assesses the function of the temporomandibular joint. The patient is asked to sublux the jaw, and the position of the lower incisors is compared to the position of the upper incisors.
A class III assessment (like the patient in this question) suggests a more difficult laryngoscopy.
Click on the region of the LMA that rests against the cricopharyngeus muscle.
Distal end → Upper esophageal sphincter (cricopharyngeus muscle)
Sides → Pyriform sinuses
Proximal end → Base of the tongue
Identify the contraindications to the device in the image. (Select 3.)
Zenker’s diverticulum
Klippel-Feil
Obesity
Prolonged used
Full stomach
Intact gag reflex
Intact gag reflex
Prolonged use
Zenker’s diverticulum
The Combitube is a supraglottic, double lumen device that is blindly placed in the hypopharynx. Contraindications to its use include:
Intact gag reflex
Prolonged use (> 2 - 3 hours) due to risk or ischemia from oropharyngeal balloon
Esophageal disease (Zenker’s diverticulum)
Ingestion of caustic substances
Do not use a size 37-F in someone < 4 ft
Do not use a size 41-F in someone < 6 ft
It provides a secure airway, so it is a useful alternative in the patient with a full stomach. Additionally, placement does not require neck extension, so it’s useful in the patient with Klippel-Feil syndrome.
Identify the statements that BEST describe the device in the image. (Select 2.)
There are no disposable components.
The oral, pharyngeal, and laryngeal axes must align.
It requires a minimum mouth opening 7 millimeters.
It is useful in the patient with Pierre-Robin syndrome.
It requires a minimum mouth opening 7 millimeters
It is useful in the patient with Pierre Robin syndrome
The Bullard laryngoscope is a rigid, fiberoptic device used for indirect laryngoscopy. For this reason, the oral, pharyngeal, and laryngeal axes do not have to align.
It is useful in the patient with:
Small mandible (Pierre-Robin syndrome)
Limited mouth opening (requires at least 7 mm)
Limited cervical mobility
There is a disposable tip extender that is useful for tall patients. It snaps in place before laryngoscopy and it must be removed and discarded after laryngoscopy.
Click on the laryngoscopic view where the Eschmann introducer provides the MOST significant benefit.
Remember the Cormack and Lehane grading system?
The Eschmann introducer provides the most significant benefit when you obtain a grade III view during laryngoscopy.
Before moving on, what are some other names for the Eschmann introducer?
lick on the area where the wire is inserted during retrograde intubation.
Just like cricothyroidotomy, retrograde intubation requires you to penetrate the cricothyroid membrane.
Click on the left cricothyroid muscle
Click on the region of the alveolar compliance curve where ventilation is the greatest.
Alveolar ventilation is a function of alveolar size and its position on its compliance curve (Alveolar compliance = Alveolar volume / Alveolar Pressure).
The best ventilated alveoli are the most compliant.
They exchange more gas, because their volumes change more throughout the respiratory cycle.
These alveoli reside at the steep slope of the curve.
The least ventilated alveoli are the least compliant.
They exchange less gas, because their volumes change very little throughout the respiratory cycle.
These alveoli reside near the top of the curve.
Which letter corresponds with the region where dead space is the greatest?
A
B
C
D
D
Explanation:
Dead space is ventilation without perfusion and shunt is perfusion without ventilation.
The graph examines the V/Q relationship in the entire lung.
Point C marks where ventilation and perfusion are equally matched.
Point D marks the region where ventilation is greater than perfusion; dead space is increased here.
Points A and B mark where perfusion exceeds ventilation; shunt is increased here.
A patient is scheduled for a VATS with lung resection. Click on the alveolar compliance curve that BEST illustrates what happens after he is anesthetized and placed in the lateral decubitus position.
When the anesthetized patient is placed in the lateral decubitus position:
The nondependent lung moves from the flat (noncompliant) region of the curve to an area of better compliance. Ventilation is best here, because the lung is on a favorable position of the curve.
The dependent lung moves from the slope (highly compliant) to the lower, flatter area of the curve. In this region, the reduction of alveolar volume contributes to atelectasis. Perfusion is best here due to gravity.
The net effect is that ventilation is better in the nondependent lung and perfusion is better in the dependent lung. This creates V/Q mismatch.
What is this patient’s Mallampati classification?
(Enter your answer as a number)
Three
Explanation:
The Mallampati score is used to assess the size of the tongue relative to the volume of the mouth. The more space the tongue occupies, the less space there is to work
To perform the exam, the patient should sit upright, extend the neck, open the mouth as wide as possible, and stick out the tongue. The patient should not phonate.
Remember the mnemonic: PUSH
Class I: Pillars, Uvula, Soft palate, Hard palate
Class II: __ Uvula, Soft palate, Hard palate
Class III: __ __ Soft palate, Hard palate
Class IV: __ __ __ Hard palate
By itself, the MMT is a poor predictor of difficult airway, however its predictive power increases substantially as it is combined with additional airway tests.
Following placement of the device in the image, the distal balloon is MOST likely to occlude the:
hypopharynx.
esophagus.
mainstem bronchus.
trachea.
Esophagus
Explanation:
The Combitube is a supraglottic, double lumen device that is blindly placed in the hypopharynx. The proximal balloon occludes the hypopharynx, while the distal balloon occludes the esophagus.
If the tip is placed in the esophagus (this is common), the lungs can be ventilated through the lumen between the distal and proximal balloons.
It is uncommon that the tip is positioned in the trachea, but if you get lucky, the distal lumen can be used for ventilation.
Pathology at or below the larynx may render this device useless. Esophageal rupture has been reported. Cricoid pressure should be released (not maintained) when placing the Combitube.
This is not a double lumen endotracheal tube!
What is the next best step during an intubation with a lighted stylet?
Advance the lighted stylet three inches.
Turn off the light.
Pass the endotracheal tube off of the lighted stylet.
Withdraw and reposition the lighted stylet.
Pass the endotracheal tube off of the lighted stylet
The trachea is anterior to the esophagus. Placement of the lighted stylet into the trachea results in a “well-defined circumscribed glow” below the thyroid prominence. This is what you saw in the image. If the lighted stylet was in the esophagus, you would observe a “more diffuse transillumination of the neck without the circumscribed glow.”
Esophageal placement = diffuse transillumination of the neck without the circumscribed glow
Tracheal placement = well defined circumscribed glow just below the thyroid prominence
Benefits of the lighted stylet:
Useful for the anterior airway.
Useful with small mouth opening.
Requires very little manipulation of the neck.
Less stimulating than direct vision laryngoscopy.
Less sore throat than direct vision laryngoscopy.
Downsides of the lighted stylet:
It should not be used in a can’t ventilate can’t intubate scenario.
More difficult to use in the patient with a short, thick neck.
It’s a blind technique and shouldn’t be used in the presence of tumor, foreign body, or airway injury.
Click on the paravertebral ganglion.
The paravertebral ganglia are where the pre- and postganglionic fibers in the SNS synapse.
There are 31 paired ganglia, and collectively they make up the sympathetic chain.
Click on the white ramus.
In the sympathetic nervous system, the preganglionic sympathetic fibers exit the spinal cord via the ventral nerve roots of the spinal nerves. These fibers enter the sympathetic chain by way of the white communicating rami.
Which of the following enzymes is represented by the blue box?
Guanylate cyclase
Phospholipase C
Phosphodiesterase
Adenylate cyclase
Phospholipase C
Explanation:
The image in this question represented the alpha-1 receptor.
1st messenger: phenylephrine, norepinephrine
Receptor: alpha-1
Effector enzyme: phospholipase C
2nd messenger: IP3, DAG, and Ca+2
Other receptors that behave this way include: vasopressin-1, histamine-1, muscarinic-1, and muscarinic-3.
Click on dobutamine.
A catecholamine contains two key components:
Catechol nucleus (benzene ring with a hydroxyl group in the 3rd and 4th position)
Amine side chain
Catecholamines from smallest to largest:
dopamine –> norepinephrine –> epinephrine –> isoproterenol –> dobutamine.
The synthetic catecholamines (isoproterenol and dobutamine) are larger than the endogenous catecholamines.
Dobutamine is the only one that has two benzene rings.
Click on the region of the ventricular action potential where calcium conductance is the greatest.
The most important ion currents during each phase of the ventricular action potential:
Phase 0 = Sodium in
Phase 1 = Chloride in
Phase 2 = Calcium in
Phase 3 = Potassium out
Phase 4 = Sodium out
Click on the area of the pressure volume loop where the mitral valve closes.
The LV sits between two valves, and each valve can assume two different positions (open or closed).
There are four corners on the LV pressure volume loop. At each corner, one of the valves assumes a new position.
Mitral valve:
Opens in the bottom left corner
Closes in the bottom right corner
Aortic valve:
Opens in the upper right corner
Closes in the upper left corner
Calculate the stroke volume.
(Enter your answer in mL)
70 mL
Explanation:
If you are given a pressure volume loop, then the stroke volume is equal to the width of the loop.
Stroke volume = LV end-diastolic volume - LV end-systolic volume
120 mL - 50 mL = 70 mL
Click on the region of the myocardium that is supplied by the circumflex artery.
When using TEE, the midpapillary muscle level in short axis provides the best view for diagnosing myocardial ischemia.
The circumflex a. supplies the left lateral wall of the LV.
The left anterior descending a. supplies the anterior wall of the LV, anterior two thirds of the septum and a small portion of the anterior RV.
The right coronary a. supplies the posterior wall of the LV, most of the RV, and the posterior third of the septum.
Click on the curve that corresponds with coronary blood flow through the left ventricular subendocardium.
The top waveform is aortic pressure.
The middle waveform corresponds to the circulation through the LV. Notice that flow dramatically decreases during systole.
The bottom waveform corresponds to the circulation through the RV. Notice that it is well perfused throughout the cardiac cycle.
A 70-year-old male with an intertrochanteric femur fracture presents for an ORIF of the hip. He reports a history of chest pain and syncope. Concerned about the possibility of aortic stenosis, you auscultate his chest. Click on the region where the murmur of aortic stenosis is heard BEST.
You should know where to listen to each valve.
The patient in this question has aortic stenosis, and the highlighted region illustrates the best place to listen for this murmur.
Click on the pressure-volume loop that represents chronic aortic regurgitation.
If you’ve been following along, this one should’ve been pretty easy. Hopefully as you read this question, you took the time to reason through each pressure-volume loop. Repetition really is the key to understanding this stuff.
Top left = mitral stenosis
Top right = aortic stenosis
Bottom left (small) = acute aortic regurgitation
Bottom left (large) = chronic aortic regurgitation
Bottom right (small) = acute mitral regurgitation
Bottom right (large) = chronic mitral regurgitation
Click on the curve that BEST represents the ventricular compliance of the patient with aortic stenosis.
If you just completed the Valvular Heart Disease Tutorial, you’ll remember that aortic stenosis causes pressure overload and concentric hypertrophy.
The extra thickness impairs the ventricle’s ability to relax, reducing its compliance (the curve shifts up and left).
Click on the thoracoabdominal aneurysm that is associated with the HIGHEST incidence of paraplegia following open surgical repair.
The Crawford system classifies thoracoabdominal aortic aneurysms based on their location. There are four types.
Type II aneurysms present the most significant risk for paraplegia and/or renal failure following surgery. This is because there’s a mandatory period of stopping blood flow to the renal arteries and some of the radicular arteries that perfuse the anterior spinal cord (possibly including the artery of Adamkiewicz).
It’s recommended that methods to reduce the risk of ischemic injury (to be covered shortly) be used in these patients.
Click on the region of the ventricular action potential where potassium conductance is the GREATEST.
Phase 0 = Na+ conductance is greatest
Phase 1 = Cl- conductance is greatest
Phase 2 = Ca+2 conductance is greatest
Phase 3 = K+ conductance is greatest
Click on the area of the pressure-volume loop where the aortic valve opens
By convention, when we learn about pressure-volume loops we are looking at the left ventricle. Blood enters via the mitral valve and exits through the aortic valve.
Each can assume 2 positions: open or closed
At each corner of the loop, 1 valve either opens or closes:
The aortic valve moves at the top of the loop. It opens on the top right corner and closes on the top left corner.
The mitral valve moves at the bottom of the loop. It opens on the bottom left corner and closes on the bottom right corner.
Which letters correspond with diastole? (Select 2.)
A
B
C
D
B
C
Diastole
B = Isovolumetric relaxation
C = Rapid & late ventricular filling and atrial kick
Systole
D = Isovolumetric contraction
A = Ventricular ejection
Click on the region that represents the relative refractory period.
The absolute refractory period is when the cell is completely resistant to depolarization. This occurs between:
The QRS complex and the top of the T wave
Phase 0 through the middle of phase 3
The relative refractory period is when the cell can be depolarized, but it requires a larger than normal stimulus. This occurs between:
The top of the T wave and the end of the T wave
The middle of phase 3 to beginning of phase 4
Electrical stimulation timed with the T wave can lead to VT/VF.
Calculate the ejection fraction from the following data.
(Enter your answer as the nearest whole percent)
69 percent
Don’t think for a moment that all of the calculation questions are going to simply ask you to input numbers into a formula. There will be times where you have to interpret data before you can use it. Obviously these types of questions are harder. Answer them correctly, and you’ll be rewarded.
EF = (SV / EDV) x 100%
The width of the pressure-volume loop is the stroke volume. So…
SV = 130 - 40 = 90 mL
EF = [(130 - 40) / 130) x 100 = 69%
A patient has a heart rate of 50 beats per minute and this pressure volume loop. Calculate the cardiac output.
(Round to two decimal places and enter your answer as a L/min)
4.5 L/min
As you can see, there are a variety of ways the NCE question writers can assess your knowledge of cardiac output.
The pressure-volume loop does not measure time, so it cannot measure any variable that occurs over time such as heart rate or cardiac output.
CO = HR x SV
The width of the pressure-volume loop is the stroke volume. Once you have this number, plug it into the equation.
CO = 50 x 90 = 4,500 mL/min converts to 4.50 L/min
Which of the following is consistent with the MOST appropriate management for the patient with this pressure-volume loop? (Select 2.)
Heart rate = 45 bpm
Pulmonary artery occlusion pressure = 12 mmHg
Systemic vascular resistance = 1500 dynes/sec/cm-5
Central venous pressure = 1 mmHg
Systemic vascular resistance = 1500 dynes/sec/cm-5
Pulmonary artery occlusion pressure = 12 mmHg
Explanation:
This patient has aortic stenosis. You should be concerned with rate, volume, and afterload.
Rate: Maintain NSR. Tachycardia reduces filling time and bradycardia creates LV distension.
Volume: Increase preload. Keep CVP and PAOP at high/normal.
Afterload: Afterload is set by the stenotic aortic valve. SVR must be kept high to help perfuse the coronary arteries (CPP = AoDBP - LVEDP).
Click on the region of the pressure-volume loop where aortic insufficiency would be seen.
The aortic valve closes at the upper left corner of the pressure-volume loop, therefore the period of isovolumetric relaxation is affected.
The line slants to the right as the ventricle accepts preload during this time. Said another way, end diastolic volume is higher than end-systolic volume.
You should envision the letter “A” in this region of the pressure volume loop in the patient with AI.
Click on the region where mitral regurgitation is heard BEST.
In the left heart, systolic murmurs are caused by aortic stenosis or mitral regurgitation, while diastolic murmurs are caused by aortic insufficiency or mitral stenosis.
Mitral stenosis and regurgitation are best heard at the apex or left axilla. MS creates an opening snap with a low intensity murmur during diastole. MR causes a loud swishing sound during systole. This is the correct answer to the question.
Aortic stenosis and insufficiency are best heard at the right sternal border. AS creates a harsh and noisy murmur during systole. AI causes a high pitch blowing murmur during diastole.
Estimate the coronary perfusion pressure.
(Enter your answer in mmHg)
42 mmHg
Explanation:
Coronary perfusion pressure = Aortic DBP - LVEDP
CPP = 60 - 18 = 42 mmHg
In this case, you had to use the a-line DBP as a surrogate for aortic DBP and also PAD as a surrogate for PAOP.
You are expected to be able to make these assumptions on boards, so if you didn’t get this correct, you’ve identified a knowledge gap you’ll need to fill before the big day.
You get extra credit if you noticed there was no SpO2 waveform.
Click on the compliance curve that correlates with condition that produces the arterial blood pressure waveform pictured to the right of your screen.
This was a difficult one.
Diastolic compliance describes the ventricular filling pressure that results from a given end-diastolic volume.
C ventricle = Ventricular volume / Ventricular pressure
Decreased Cv results from conditions that cause a stiff heart. The curve shifts up and left.
Increased Cv results from conditions that dilate the heart. The curve shifts down and right.
Now is where it gets fun…
The arterial waveform in the image illustrates a bisferiens pulse, and this can occur in the patient with aortic insufficiency (increased Cv). Take note of the sharp upstroke, low diastolic pressure, wide pulse pressure, and most importantly, the biphasic systolic peaks. See the Cardiac II Valvular Heart Disease question 6 for more detail.
Notice how this one question pulls from several content areas? Expect the NCE to do the same.
Click on the phase of the cardiac action potential that is blocked by potassium in the cardiopelegia solution.
The goal of myocardial preservation is to reduce myocardial damage that occurs during cardiopulmonary bypass.
Cardioplegia is introduced into the aortic root, where the solution then enters the coronary arteries. For this to occur, the aortic valve must be competent (no AI) and the aorta clamped. Alternatively, retrograde cardioplegia may be administered through a cannula placed in the coronary sinus.
Potassium in the cardioplegia solution arrests the heart in diastole. Recall that K+ increases resting membrane potential. This initially activates the voltage-gated Na+ channels, but then it maintains the Na+ channels in an inactive state. Said another way, the voltage-gated Na+ channels are unable to depolarize again until the RMP returns to normal. When the surgical procedure is complete, the heart is “restarted” by infusing the coronary circulation with warm, normokalemic blood.
Heart block (after the heart is restarted) is a side effect of the cardioplegia solution. For this reason, the heart is often paced in the post-bypass period.
A patient has an aortic balloon pump in place. Click on the region of the arterial blood pressure waveform where the balloon begins to inflate.
The intra-aortic balloon pump improves myocardial oxygen supply while simultaneously reducing demand.
It inflates during diastole. This increases coronary perfusion pressure (increased supply).
It deflates during systole. This reduces afterload (decreased demand).
Click on the part of the curve that correlates with drug elimination from the plasma.
The steepest portion of the curve represents redistribution from the plasma to the tissues. This is called the alpha phase.
The less steep portion of the curve represents elimination from the plasma. This is called the beta phase.
Click the curve that represents an antagonist.
Curve A: An agonist binds to a receptor and turns on a specific cellular response.
Curve B: A partial agonist binds to a receptor, but it is only capable of eliciting a partial cellular response.
Curve C: An antagonist binds to a receptor but does not elicit a clinical response.
Curve D: An inverse agonist binds to a receptor and causes the opposite effect of the agonist.
Click on the molecule that is one half of a racemic mixture.
Chirality is a division of stereochemistry. It deals with molecules that have a center of three-dimensional asymmetry. In biologic systems, this type of asymmetry generally stems from the tetrahedral bonding of carbon – carbon binds to 4 different atoms.
A molecule with 1 chiral carbon will exist as 2 enantiomers. The more chiral carbons in a molecule, the more enantiomers that are created.
A racemic mixture contains 2 enantiomers in equal amounts.
Click on 2,6-diisopropylphenol.
answer is propofol
ketamine top right
etomidate bottom left
thiopental bottom right
Match each inhaled anesthetic with its chemical structure.
sevo 7
nitrous = obvious
iso = cl
des = 6
Click on the FA/FI curve that represents nitrous oxide.
The FA/FI curves are listed from top to bottom:
Nitrous oxide
Desflurane
Sevoflurane
Isoflurane
So if desflurane has the smallest blood:gas partition coefficient, then why is it below nitrous oxide on this graph?
Use the graph to match each letter with the drug it represents.
ABCD
Nalbuphine
Propranolol
Cisatracurium
Propofol
A + Propofol
B + Nalbuphine
C + Cisatracurium
D + Propranolol
Full Agonist:
Can maximally activate a specific cellular response.
Example: propofol
Partial Agonist:
Is only capable of partially activating a cellular response.
Example: nalbuphine
Antagonist:
Occupies the receptor binding site and prevents an agonist from binding to it. It does not tell the cell to do anything.
Example: cisatracurium
Inverse agonist:
Causes the opposite effect to that of a full agonist.
Example: propranolol
Based on the graph, what assumption can you make about drug A?
It undergoes more plasma protein binding than drug B.
It is more potent than drug C.
It has a smaller volume of distribution than drug C.
It will remain in the central compartment longer than drug D during elimination.
It will remain in the central compartment longer than drug D
If you recognized this as the context-sensitive half-time chart for the phenylpiperidines, then pat yourself on the back.
The concept of context-sensitive half-time takes the duration of drug administration into account. It is the time required for a steady-state plasma concentration to decline by 50% after an infusion or repeated drug dosing is stopped (context = time).
A major flaw with this concept is that it only illustrates the time it takes for the concentration to decline by 50% in the central compartment. This means that context-sensitive half-time does NOT necessarily predict the time to wake-up after an infusion is stopped.
Drug A at the top of the graph (fentanyl) had the longest context-sensitive half-time, while drug D at the bottom of the graph (remifentanil) has the shortest context-sensitive half-time.
Click on the chemical structure that represents ketamine.
Click on the curve that represents propofol distribution to the brain.
At time = 0, all of the injected propofol is in the blood.
Cp declines over time.
Propofol is rapidly distributed from the blood and into the vessel rich group.
The brain concentration peaks at ~ 1 min, then propofol redistributes from the VRG to the muscle and adipose. Notice how the drug continues to redistribute to the muscle and fat over time.
Awakening is the result of redistribution away from the brain - NOT metabolism.
Time to awakening is 5 - 15 minutes.
Match each anesthetic with the letter that represents its FA/FI curve.
Which drugs are represented by curve B? (Select 2.)
Buprenorphine
Naloxone
Butorphanol
Nalmefene
Butorphanol
Buprenorphine
Curve A represents a full agonist. Examples include morphine and fentanyl.
Curve B represents a partial agonist. Examples include buprenorphine and butorphanol.
Curve C represents an antagonist. Examples include naloxone and nalmefene.
Curve D represents an inverse agonist. We couldn’t find any examples suitable for this tutorial.
Regarding the structure of local anesthetics, match each molecular component with its medicinal chemistry.
The local anesthetic molecule is constructed from 3 key components:
- Benzene Ring:
Lipophilic (permits diffusion through lipid bilayers)
- Intermediate Chain:
Class - ester or amide
Metabolism
Allergic potential
- Tertiary Amine:
Hydrophilic
Accepts proton
Makes molecule a weak base
*Nagelhout says it’s a quaternary amine, but this isn’t right.
Which of the following illustrations BEST represents the mechanism of action of a local anesthetic?
hard to see
After you inject local anesthetic around a nerve, the local anesthetic rapidly dissociates into an uncharged base (LA) and an ionized, conjugate acid (LA+).
The uncharged base (LA) enters the axon, and once inside the nerve, a new equilibrium is established.
Only the ionized, conjugate acid (LA+) binds to the local anesthetic binding site (alpha-subunit) on the inside of the voltage-gated sodium channel.
The sodium channel remains in the closed, inactivated state until enough local anesthetic diffuses away.
The adductor pollicis muscle can be stimulated by placing the negative electrode at points: (Select 2.)
A.
B.
C.
D.
B
C
Stimulation of the ulnar nerve results in contraction of the adductor pollicis muscle. Visually this appears as thumb ADDuction; not pinky finger ADDuction or flexion.
The adductor pollicis recovers later than the diaphragm, laryngeal adductors, and abdominal muscles, however it recovers at the same time as the geniohyoid. The take away is that if the adductor pollicis is not recovered, then the geniohyoid probably isn’t either and this increases the risk of upper airway obstruction.
Stimulation of the ulnar nerve at the wrist:
Negative electrode = C
Positive electrode = D
Stimulation over the adductor pollicis muscle:
Negative electrode = B
Positive electrode = A
Remember the red wire of the nerve stimulator is Positive and placed Proximal. The black wire is distal and black.
Click on the colored box that represents neostigmine.
Neostigmine produces reversible inhibition of AchE by forming a carbamyl ester complex at the esteratic site. Pyridostigmine and physostigmine share the same mechanism of action.
Edrophonium forms an electrostatic bond at the anionic site and a noncovalent hydrogen bond at the esteratic site. Since hydrogen bonds are weak, the duration of action is short.
Organophosphates produce non-reversible inhibition of AchE by forming a stable complex with the esteratic site. New acetylcholinesterase must be synthesized, which explains why organophosphates have an extended duration of action.
Click on the curve that represents nalmefene.
click on the annular space
The annular space is the area between the widest area of the indicator float and side wall of the flowmeter.
This is an image of a skirted float, which is read at the top of the float.
Choose the statement that BEST describes this vaporizer. (Select 2.)
It is heated to 42 degrees.
It uses a flow-over design.
It is pressurized to two atmospheres.
Its output is increased inside a hyperbaric chamber.
It is pressurized to two atmospheres
Its output is increased inside a hyperbaric chamber
Explanation:
The Tec 6 desflurane vaporizer injects anesthetic vapor into the fresh gas (it does not use a flow-over design). The chamber that contains the anesthetic agent is pressured to two atmospheres and heated to 39 (not 42) degrees C.
The vaporizer output varies inversely with elevation. Therefore, the vaporizer should be re-calibrated when it’s going to be used in high altitude locations.
While providing an anesthetic with a circle system, you observe this waveform. What is the BEST course of action at this time? (Select 2.)
Repair the expiratory valve.
Increase the patient’s minute ventilation.
Replace the carbon dioxide absorbent.
Increase the fresh gas flow in excess of the patient’s minute ventilation.
Replace the carbon dioxide absorbent.
Increase the fresh gas flow in excess of the patient’s minute ventilation.
Explanation:
This patient is rebreathing CO2. There are 2 ways to fix this. You can either replace the carbon dioxide absorbent or convert the breathing system to a semi-open system by increasing the FGF.
Increasing the minute ventilation does not prevent rebreathing. The patient will continue to inspire carbon dioxide, but now only at a faster rate.
This is not a problem with the expiratory valve. The trick to diagnosing unidirectional valve malfunction is to look at the beta angle during the inspiratory phase. If you aren’t familiar with this term, we have an image for you on the next slide.
Click on the BEST configuration for spontaneous ventilation.
The first circuit is the Mapleson E
The second circuit is the Mapleson D. This is the best configuration for controlled ventilation.
The third circuit is the Mapleson F or Jackson-Rees.
The fourth circuit in the image is the Mapleson A. This is the best configuration for spontaneous ventilation.
Which conditions are MOST likely associated with this airway pressure waveform? (Select 3.)
Endobronchial intubation
Pulmonary edema
Kinked endotracheal tube
Pneumothorax
Aspiration of foreign body
Bronchospasm
Bronchospasm
Kinked endotracheal tube
Aspiration of foreign body
Explanation:
The pressure-time waveform in this question shows an elevated peak pressure with a normal plateau pressure. This pattern suggests a reduction in dynamic compliance, which is usually caused by an increased airway resistance.
Potential causes include: bronchospasm, aspiration of foreign body, and a kinked endotracheal tube.
Click on the region of the capnograph that represents mixing of alveolar gas and anatomic dead space gas
Phase II (B-C) represents exhalation of anatomic dead space + alveolar gas. This is illustrated by the upstroke on the capnograph waveform.
Click on the capnograph that represents a sample line leak.
Airflow Obstruction
Prolonged upstroke with increased alpha angle.
Examples: COPD, bronchospasm, kinked ett.
Cardiac Oscillations
Result from the heart beating against the lungs.
More common in children (close proximity of heart to the lungs).
Curare Cleft
Spontaneous breaths during mechanical ventilation.
If present during spontaneous ventilation, the presence of a curare cleft suggests inadequate muscle relaxant reversal (lack of synchronization between intercostal muscles and diaphragm).
Low EtCO2
The plateau phase is well below normal. Look for a scale or a reference wave.
Occurs with hyperventilation, ↓ CO2 production, or ↑alveolar dead space.
Examples: hyperventilation: light anesthesia, metabolic acidosis.
Examples: ↓ CO2 production: hypothermia.
Examples: ↑ alveolar dead space: hypotension, pulmonary embolism.
Elevated EtCO2 with Normal Plateau
Look at the baseline. It returns to zero. This is not rebreathing.
Occurs with increased CO2 production or decreased alveolar ventilation.
Examples: ↑ CO2 production: MH, sepsis, fever, hyperthyroidism.
Examples: ↓alveolar ventilation: hypoventilation, narcotics.
Inspired CO2
Look at the baseline. It does not return to zero. This is rebreathing.
Causes include: exhausted CO2 absorbent, incompetent expiratory valve, hole in the inner tube of a Bain system, inadequate FGF with Mapleson circuit, or rebreathing under the drapes in a patient who is not intubated.
Incompetent Inspiratory Valve
There’s a decreased slope during inspiratory phase (widened beta angle). Part of the exhaled breath re-enters the inspiratory limb, so the patient rebreathes some of the previously exhaled CO2 on the next breath.
The waveform may or may not reach zero depending on the FGF.
Leak in Sample Line during Positive Pressure Ventilation
The beginning of the plateau is low because of dilution of alveolar gas as atmospheric air is aspirated into the sample line.
Positive pressure during inspiration pushes the CO2 rich gas through the sample line, which results in the peak at the end of the plateau.
Not seen with spontaneous ventilation, because there is no positive pressure.
This pattern may also occur in obese and pregnant patients.
Biphasic Expiratory Plateaus
This can occur after a single-lung transplant.
Alveolar gas from the transplanted lung and the diseased lung have different time constants.
The first peak is alveolar gas from the transplanted lung. It has a normal time constant.
The second peak is alveolar gas from the diseased lung. Because air is trapped in the sick lung, there is a longer time constant during exhalation.
Biphasic expiratory plateaus have also been reported with severe kyphoscoliosis.
Which conditions are MOST likely to cause this end-tidal CO2 waveform? (Select 3.)
Pulmonary embolism
Sodium bicarbonate administration
Metabolic alkalosis
Seizure
Inadequate seal with laryngeal mask airway
Metabolic acidosis
Metabolic acidosis
Pulmonary embolism
Inadequate seal with laryngeal mask airway
Explanation:
This waveform shows an abnormally low EtCO2, which can result from reduced CO2 production, increased dead space, hyperventilation, or equipment failure.
Examples include:
Metabolic acidosis (hyperventilation from increased minute ventilation)
Pulmonary embolism (increased dead space)
Inadequate seal with an LMA (equipment failure)
Click on the area on the CVP waveform that correlates with the early passive filling of the right atrium.
The CVP waveform is a measure of the right atrial pressure. It has three peaks (a, c, v) and 2 troughs (x, y).
The best way to truly understand the waveform is to correlate it with the EKG and the cardiac cycle. This will help you time the mechanical events with the pressure in the right atrium.
This question asked you to identify where passive filling of the RA occurs. This phase is represented by the v wave.
Which findings are observed when the tip of the pulmonary artery catheter enters the highlighted area? (Select 2.)
Increased pulse pressure
Increased diastolic blood pressure
Dicrotic notch
Increased systolic blood pressure
Dicrotic notch
Increased diastolic blood pressure
You should be able to explain the pressure changes as the tip of the PAC travels through the heart.
When the tip enters the pulmonary artery, the diastolic pressure increases and a dicrotic notch appears. We’ll walk you through all of it on the next page.
Right Atrial Pressure
This was discussed in a previous page.
Right Ventricular Pressure
The systolic pressure increases.
The diastolic pressure is equal to CVP.
Pulmonary Artery Pressure
The systolic pressure remains about the same.
The diastolic pressure rises.
The dicrotic notch is formed during pulmonic valve closure during diastole.
Pulmonary Artery Occlusion Pressure (Pulmonary Capillary Wedge Pressure)
This waveform is akin to the CVP of the left heart.
The a wave is caused by left atrial systole.
The c wave is caused by mitral valve elevation into the LA during LV systole (isovolumetric contraction).
The v wave is caused by passive left atrial filling.
*We think Nagelhout is a little confused in its description of the c and v waves on the PAOP waveform.
Click on the esophageal Doppler waveform that BEST represents the administration of sodium nitroprusside.
Image A = Hypovolemia and then response to fluid bolus
Image B = Increased afterload and then response to vasodilator (sodium nitroprusside)
Image C = Myocardial depression and then response to inotrope
Diagnose each rhythm strip.
First Degree Heart Block
If “R” is far from “P” then you have a First Degree.
The PR interval is > 0.20 sec.
Affected region:
AV node or His bundle
Etiology:
Age related degenerative changes, CAD, digoxin, amiodarone
Treatment:
Monitor (usually asymptomatic)
Second Degree Heart Block (Mobitz Type I)
Longer, longer, longer, drop then you have a Wenckebach.
The PR interval becomes progressively longer with each cycle,
but the last P wave does not conduct to the ventricles. Then,
the cycle repeats.
Why does this happen? Each successive depolarization increases the duration of the refractory period in the AV node. The last P in the cycle is dropped, because it arrives at the AV node while it’s in the absolute refractory period. This beat is not conducted, but the pause that follows provides enough time for the AV node to reset. Then, the cycle repeats.
Affected Region:
AV node
Etiology:
Structural conduction defect, myocardial injury/infarction, beta-blockers, CCBs, digoxin, sympatholytic agents
Treatment:
If the patient is asymptomatic, then it is safe just to monitor
If the patient is symptomatic, then give atropine
Second Degree Heart Block (Mobitz Type II)
If some “P”s don’t get through then you have a Mobitz II.
Some P’s conduct to the ventricles, while others don’t (there is usually a set ratio 2:1 or 3:1). After the dropped QRS, the next P arrives right on time.
Affected region:
His bundle or bundle branches
Etiology:
Structural conduction defect or infarction
Treatment:
Often symptomatic (palpitations and syncope)
Pacemaker (transcutaneous, transvenous, or implantable)
Atropine often not effective
Key Point:
There is a high risk of progressing to complete heart block
Third Degree Heart Block
If “P”s and “Q”s don’t agree then you have a Third Degree.
The atria and ventricles each have their own rates (AV dissociation)
Block in the AV node has a narrow QRS (rate 45-55 bpm)
Block below the AV node has a wide QRS (rate 30-40 bpm)
Etiology:
Fibrotic degeneration of the atrial conduction system, Lenegre’s disease
Treatment:
Often symptomatic (dyspnea, syncope, weakness, vertigo)
Pacemaker (transcutaneous, transvenous, or implantable)
Isoproterenol (chemical pacemaker)
Key Points:
Can lead to CHF due to decreased HR and CO.
Stokes-Adams attack = decreased CO → decreased cerebral perfusion → syncope
The Heart Block Rhyme
If “R” is far from “P” then you have a First Degree.
Longer, longer, longer, drop then you have a Wenckebach.
If some “P”s don’t get through then you have a Mobitz II.
If “P”s and “Q”s don’t agree then you have a Third Degree.
Check out a YouTube video where you can watch a few guys teach cardiac dysrhythmias through their killer dance moves.
A while after we linked to this video, we received an email from one of our students saying that she created it in nursing school. We’re forever thankful that she saved us the time and humiliation of having to do it ourselves :)
A patient is receiving controlled ventilation with a fresh gas flow of 5 L/min. Click on the circuit that is MOST likely to cause hypercarbia.
Not only do you have to be able to identify each circuit, but you have to know which are best for controlled ventilation.
The Mapleson A is the worst configuration for controlled ventilation (best to worst): DFE > BC > A
Notice the fresh gas flow enters far from the patient and that the APL valve is close to the patient. This combination is what makes the Mapleson A the worst design for controlled ventilation. A fresh gas flow as high as 20 L/min is required to prevent rebreathing!
This specific configuration is also what makes the Mapleson A the best design for spontaneous ventilation (best to worst): A > DFE > CB
Click on the circuit that is the predecessor to the Bain system.
The Mapleson D (2nd example) is the precursor to the Bain system.
What’s different about the Bain system is that the fresh gas travels towards the patient through a smaller tube INSIDE the corrugated tubing.
Exhaled gas travels inside the corrugated tubing (but outside of the small tube discussed above). This design passively warms the incoming fresh gas.
Click on the phase of the capnograph that BEST correlates with the ventilation-perfusion status of the lung.
Phase I = Exhalation of dead space
Phase II = Exhalation of dead space + alveolar gas
Phase III = Exhalation of alveolar gas (best correlates to V/Q status)
Phase IV = Inspiration
Point D = Point of EtCO2 measurement
Click on the beta angle.
There are two angles on the capnograph: alpha and beta
Alpha angle:
Between phase II and III
Normal = 100-110 degrees
Increased by obstruction to expiration, such as COPD, kinked endotracheal tube, etc.
Beta angle:
Between phase III and IV
Normal = 90 degrees
Increased by an inspiratory valve stuck in the open position
Match each event with its MOST likely presentation on the capnograph.
Channeling + Elevated baseline
Incompetent inspiratory valve + Widened beta angle
Sample line leak + Peak at end of phase 3
Tournequet release + Increased EtCO2 with normal return to baseline
What is the distance from the junction of the vena cava and the right atrium to the tip of this PA catheter?
10 cm
20 cm
40 cm
60 cm
20 cm (It’s usually 15-30 cm, but 20 cm was the only answer choice in this range)
Explanation:
We made this question easier than we could have, but in case you’re not so lucky on the NCE, here’s a simple way to calculate the distance from any insertion site to the tip of the PA catheter anywhere in the heart.
To do this, you’ll need to know two pieces of information: the distance from the insertion site to the junction of the VC and then the distance from the junction of the VC and RA to the tip of the catheter. Then add these numbers together.
Distance from the insertion site to the junction of the VC and RA:
Left or right subclavian: 10 cm
Right internal jugular: 15 cm
Left internal jugular: 20 cm
Femoral: 40 cm
Right median basilic: 40 cm
Left medial basilic: 50 cm
Distance from the junction of the VC and RA to the tip of the catheter:
Right atrium: 0-10 cm
Right ventricle: 10-15 cm
Pulmonary artery: 15-30 cm
PAOP position: 25-35 cm
Which of the following is observed as the tip of the pulmonary artery catheter enters this cardiac chamber? (Select 2.)
The diastolic pressure increases.
The systolic pressure increases.
The pulse pressure increases.
There is a dicrotic notch.
The systolic pressure increases
The pulse pressure increases
The PA catheter has advanced from the right atrium into the right ventricle. Here, the systolic pressure increases, and this increases the pulse pressure.
As you advance the PA catheter further, it will transverse the pulmonic valve and enter the pulmonary artery. You’ll know you’ve arrived when you notice a dicrotic notch and a rise in diastolic pressure.
When reviewing questions, don’t just learn the question and move on. Quiz yourself about other key ideas related to the topic being addressed. For example, here you might want to consider intracardiac distances, the pressures in each chamber, or complications of PA catheter placement.
This EKG indicates:
normal axis.
left axis deviation.
right axis deviation.
extreme right axis deviation.
Left axis deviation
Explanation:
The electrical axis indicates the direction of depolarization as it travels through the myocardium.
We can illustrate the general direction of the movement of depolarization by using a vector.
The mean electrical vector is the summation of all of the vectors of ventricular depolarization.
The mean electrical vector tends to point towards ventricular hypertrophy and point away from myocardial infarction.
To determine the axis or the direction of the mean electrical vector, you have to look at the QRS complex in lead I and AVF.
Normal axis: lead I and AVF are positive
Extreme right axis: lead I and AVF are negative
Right axis: lead I is negative and AVF is positive
Left axis: lead I is positive and AVF is negative
This EKG tracing represents a:
non-compensatory pause.
Mobitz type II block.
antidromic pathway.
sinus arrhythmia.
Non-compensatory pause
Explanation:
This EKG shows an example of a premature atrial contraction. A PAC originates from an ectopic focus in the atria. The P wave comes early and has a different morphology. The PAC is followed by a non-compensatory pause.
In this tracing, the QRS complexes are orthodromic (they are conducted through the AV node). The QRS morphology is normal.
An antidromic pathway is an accessory pathway that bypasses the AV node (think of the Bundle of Kent and Wolff-Parkinson-White syndrome). The QRS morphology is abnormally wide.
Click on the bipolar limb lead that is ALWAYS positive.
There are three bipolar limb leads, and each one has a positive and a negative pole. The mean electrical vector travels away from the negative pole and towards the positive pole.
Lead I: Right arm (-) to Left arm (+)
Lead II: Right arm (-) to Left leg (+)
Lead III: Left arm (-) to Left leg (+)
Notice that the left leg is always positive and the right arm is always negative.
Click on the area of the hexagonal reference system that correlates with left axis deviation.
90 to - 30 degrees
Explanation:
The electrical axis depicts the path of the mean electrical vector. This vector tends to move towards areas of hypertrophy and away from areas of infarction.
The normal axis is -30 to +90 degrees.
Here are an easy set of ranges to remember:
Left axis deviation = < -30 degrees
Right axis deviation = > 90 degrees
You will find some books that describe superior right axis deviation (+180 to - 90).
Match each dysrhythmia with its EKG tracing.
Which conditions are MOST closely associated with the following abnormality? (Select 2.)
Hypermagnesemia
Hypokalemia
Digitalis toxicity
Parasympathetic stimulation
Hypokalemia
Digitalis toxicity
Explanation:
Premature ventricular contractions originate from foci below the AV node. As such, the QRS complex is wide.
PVCs that arise from a single location are unifocal (the morphology is the same on the EKG).
PVCs that arise from multiple locations are multifocal (there are different QRS morphologies on the EKG).
There are many conditions that are associated with the development of PVCs. Examples include:
SNS stimulation (hypoxia, hypercarbia, acidosis, light anesthesia)
Myocardial ischemia and/or infarction
Valvular heart disease
Cardiomyopathy
Prolonged QT interval
Hypokalemia
Hypomagnesemia
Digitalis toxicity
Caffeine
Cocaine
Alcohol
Mechanical irritation (central line insertion)
Click on the area where a PVC can cause ventricular tachycardia.
Relative refractory period (last 2/3’s of the T wave)
Explanation:
The T wave represents ventricular repolarization. During repolarization, there is the absolute refractory period and relative refractory period.
Absolute refractory period = a new action potential cannot be generated no matter how large the stimulus. This occurs between the Q wave and the first 1/3 of the T wave.
Relative refractory period = a new action potential can be generated, however a larger stimulus is required. This occurs during the last 2/3’s of the T wave.
If a PVC occurs during the relative refractory period, it is possible that sustained ventricular tachycardia or ventricular fibrillation can result. This is called the “R on T” phenomena. QT prolongation increases the risk of R on T.
As an aside, sync mode during cardioversion prevents shock delivery from occurring during ventricular repolarization.
Choose the BEST treatments for this patient. (Select 2.)
Transcutaneous pacing
Atropine
Isoproterenol
Epinephrine
Transcutaneous pacing
Isoproterenol
Explanation:
This EKG is an example of third degree (complete) heart block. No conduction occurs through the AV node. Because of this, the atria and the ventricles depolarize at their own rates - that is to say that the atria and ventricles each have their own pacemaker.
Third degree heart block is an indication for transcutaneous or transvenous pacing. If heart block does not resolve, the patient should receive an implantable pacemaker. Isoproterenol can be used as a “chemical pacemaker” until other forms of pacing are available.
Antidysrhythmic medications should be avoided. They might suppress the rescue ventricular pacemaker that is responsible for maintaining the ventricular rate. A slow rate is better than no rate at all!
Click on the arrow representing the BEST lead for monitoring the P wave.
Become familiar with the hexagonal reference system. This graphic illustrates the electrical axis of each limb lead.
Lead II is a bipolar limb lead that has a negative electrode on the right chest or arm and a positive electrode on the left leg.
Lead II is considered the best lead to monitor dysrhythmias because the P wave is best visualized with this lead.
Click on the region of the cerebral blood flow graph that represents PaCO2.
PaCO2 - black line
Cerebral perfusion pressure - green line
PaO2 - purple line
Intracranial pressure - red line
Click on the dorsal column on the right side of the spinal cord
ANSWER IS 11 OCLOCK ON THE CLOCK
First you must identify the ventral and dorsal region of the cord.
From here, look at the name of the pathway. Hotspot questions give you a sizeable area on which you can click, so if it’s the dorsal column, click on the dorsal region of the white matter (on the correct side) and you’ll be in great shape.
It’s possible that the image could be flipped upside down. Look at the orientation of the grey matter (the letter H) to make this determination.
What is the name of the angle highlighted in the image?
Robertson
Cobb
Gibson
Louis
Cobb
Explanation:
The Cobb angle describes the magnitude of spinal curvature in the patient with scoliosis.
The angle of Louis is also known as the sternal angle. This correlates with the second rib, T4, carina, and aortic arch.
We’re sure Gibson and Robertson were great guys, but as far as we can tell, they didn’t contribute anything to this topic.
Click on the odontoid process.
The odontoid process is a superior boney projection off the axis (C2). It facilitates head rotation.
This structure is bordered anteriorly by the anterior arch of the atlas (C1) and posteriorly by the transverse axial ligament.
Click on the region of the cerebral blood flow graph that represents PaO2.
Purple line = PaO2 (correct answer)
Black line = PaCO2
Green line = Cerebral perfusion pressure
Red line = ICP
Click on the left oculomotor nerve.
There are 12 pairs of cranial nerves. You can begin at the top and count as you go down to arrive at the correct answer.
The oculomotor nerve (CN III) is the third pair from the top. It is responsible for pupil constriction and eye movement specifically:
Superior rectus (supraduction)
Inferior rectus (infraduction)
Medial rectus (adduction)
Inferior oblique (extorsion and elevation)
CN VI innervates the lateral rectus (abduction).
CN IV innervates the superior oblique (intorsion and depression).
A patient with an elevated ICP and a midline shift has a fixed and dilated left pupil. Click on the cranial nerve that is affected.
The left oculomotor nerve (CN III) is the third nerve from the top. It is responsible for pupil constriction.
An extremely elevated ICP causes the uncus of the temporal lobe to herniate over the tentorium cerebelli. This puts direct pressure on CN III, which leads to ischemia, loss of function, and unopposed sympathetic stimulation to the pupil resulting in a fixed and dilated pupil.
Click on the cranial nerve that is responsible for right sided tic douloureux.
The trigeminal nerve is the fifth from the top. It divides into three branches: ophthalmic (V1), maxillary (V2), and mandibular (V3).
Tic Douloureux is another name for trigeminal neuralgia. It causes intense unilateral facial pain. The pathophysiology is unclear, however sometimes the superior cerebellar artery compresses the trigeminal nerve. Medical treatment consists of anticonvulsants. Carbamazepine is the drug of choice. Surgical treatment consists of radiofrequency destruction, transection of the sensory root, and microsurgical decompression.
Stimulation of CN V can elicit the trigeminocardiac reflex leading to bradycardia. Placement of a retractor to access the CN V root can stretch the vestibular nerve (CN VIII). Brainstem auditory evoked potentials can minimize this risk.
Name the type of nerves represented by the red question mark.
Cranial nerves
Explanation:
The peripheral nervous system is made up of cranial and spinal nerves. We listed spinal nerves, so cranial nerves was the correct answer - yes this was a give me.
The fill in the blank boxes on the NCE will only ask you to enter a number. It could either be a calculation or perhaps the number of a cranial nerve. According to the question writing guidelines published on the NBCRNA website, there is no fill in the blank for text. We’re just having a little fun.
Click on the superior articular process. (Select 2.)
Although you probably didn’t expect to see “select two” for a hotspot question, we wanted to reinforce the point that you must always read the question in its entirety. Questions like this are fair game on the SEE and NCE.
Click on the Whitacre spinal needle.
1st needle = Whitacre
2nd needle = Sprotte
3rd needle = Quincke
Match the branches of the brachial plexus with their cutaneous innervations.
Radial + A
Median + B
Ulnar + C
Explanation:
This question tests your understanding of the cutaneous distribution of the branches in the hand.
A: Radial - palmar side of thumb (C6)
B: Median - tip of index finger (C7)
C: Ulnar - tip of pinky finger (C8)
Click on the region where the local anesthetic should be injected for an interscalene block.
The brachial plexus appears as several circles in-between the anterior and middle scalene muscles.
Local anesthetic is injected into the sheath that surrounds the brachial plexus.
Note the medial and lateral indicators.
Injection of local anesthetic at the green box shown in the image will anesthetize the:
musculocutaneous nerve.
median nerve.
ulnar nerve.
radial nerve.
The three terminal nerves of the hand can be blocked at the level of the forearm or at the wrist:
Radial
Ulnar
Median
The nerve block in the image would anesthetize the radial nerve, where local anesthetic is injected between the biceps tendon and brachioradialis at the level of the elbow.
Click on the region of needle insertion for the performance of a median nerve block.
At the wrist, the median nerve is anesthetized by injecting 5 mL between the flexor carpi radialis tendon and the flexor palmaris longus tendon.
Match each cutaneous innervation with the corresponding letter in the image.
Superficial peroneal
Posterior femoral cutaneous
Sural
Obturator
Posterior femoral cutaneous + A
Obturator + B
Superficial peroneal + C
Sural + D
Match each structure with its corresponding letter in the image.
Femoral nerve
Femoral vein
Femoral artery
Fascia lata
A + Femoral vein
B + Femoral artery
C + Fascia lata
D + Femoral nerve
Explanation:
You can remember the order of the neurovascular structures with the mnemonic “VAN”
From medial to lateral: Vein → Artery → Nerve
Match each spinal needle with its corresponding image.
Spinal needles are classified in two ways: cutting and non-cutting tip
Cutting Tip
Examples: Quincke, Pitkin
Non-Cutting-Tip (pencil point and rounded bevel tip)
Pencil point examples = Sprotte, Whitacre, Pencan
Bevel tip example = Greene
When compared to a cutting-point tip needle, non-cutting tip needles carry a lower risk of PDPH, are less likely to injure the cauda equina, are less likely to deflect during insertion, and permit a better tactile experience.
The only real benefit of a cutting tip needle is that it requires less force during insertion.
Match each epidural needle with its corresponding image.
The Tuohy needle has the most pronounced curvature. This curvature plus its blunt tip helps prevent dural puncture.
Notice that the needle angle increases in alphabetical order:
Crawford = 0 degrees
Hustead = 15 degrees
Tuohy = 30 degrees
Immediately after the completion of a spinal anesthetic, the patient is placed in the supine position. Based on the image, select the local anesthetic that was administered.
Bupivacaine 0.3% in water
Lidocaine 0.5% in water
Procaine 10% in water
Tetracaine 0.2% in water
Procaine 10 percent in water
Explanation:
To understand baricity, we must first understand density:
Density = Mass / Volume
Baricity describes the density of local anesthetic solution relative to the density of the CSF.
Baricity = LA density / CSF density
CSF density = 1.0003 at 37 C
As a general rule, you can predict the relative baricity of the LA solution based on its diluent:
Dextrose = Hyperbaric (sinks)
Saline = Isobaric (remains in place)
Water = Hypobaric (floats)
The image clearly showed a hyperbaric local anesthetic solution, because it pooled in the thoracic kyphosis as well as the sacrum after the patient was positioned supine.
Given that all of the answer choices contain water, how could one of these be hyperbaric? This is what we mean by learning on a deeper level; not only must you know the generalities, but you must also know the exceptions to these rules!
Procaine 10 percent in water is the exception - it is a hyperbaric solution! This is due to the fact that there are so many molecules in the solution (it makes it heavy).
Match each terminal branch of the brachial plexus to its sensory distribution.
Median
Musculocutaneous
Ulnar
Radial
Ulnar + A
Median + B
Radial + C
Musculocutaneous + D
Click on the posterior cord.
The posterior cord arises from all five roots (C5-T1).
It is formed by the posterior divisions (all three).
It is called the posterior cord, because it is posterior to the axillary artery.
Match each upper extremity block to its targeted section of the brachial plexus.
Interscalene
Infraclavicular
Supraclavicular
Axillary
Interscalene = Roots (E)
Supraclavicular = Trunks and divisions (C or D)
Infraclavicular = Cords (B)
Axillary = Terminal branches (A)
Click on the axillary artery.
After an axillary block, the patient says she can feel the lateral aspect of her forearm. Click on the nerve that was spared.
The musculocutaneous nerve was missed. This structure resides between the biceps and coracobrachialis muscles.
The musculocutaneous nerve provides sensation to the lateral aspect of the forearm.
Which letter marks the femoral artery?
A
B
C
D
B
Explanation:
You can remember the order of the neurovascular structures with the mnemonic “VAN”
From medial to lateral: Vein → Artery → Nerve
A + Femoral vein
B + Femoral artery
C + Fascia lata
D + Femoral nerve
Click on the region of the foot that is anesthetized by injecting local anesthetic between the between the Achilles tendon and lateral malleolus.
This question asked about the area anesthetized by a sural nerve block.
Click on the area of the Starling curve that BEST correlates with preload dependence.
When the patient resides on the lower portion of the Starling curve, additional fluid increases sarcomere stretch (this increases cross-bridge formation), resulting in a greater cardiac output. This is called “preload dependence.”
Said another way, this patient is volume responsive and is a candidate for additional volume resuscitation.
Fill in the missing coagulation factor.
(Enter your answer as a name or number)
Three
The image shows the classical extrinsic coagulation cascade.
This process begins with vascular injury or when extravascular tissue comes into contact with blood as it leaks through the vessel wall.
Factor 3 (tissue factor) begins the extrinsic pathway.
Match each hematologic abnormality to its respective thromboelastogram.
Click on the region of the thromboelastogram that measures the time to begin clot formation.
The R time represents the time to begin forming the clot.
Which thromboelastogram is MOST consistent with von Willebrand disease?
Von Willebrand disease is a disorder of platelet adhesion. It is the most common inherited disorder of platelet function.
As a qualitative platelet disorder, the platelet count is normal, but the platelets do not function properly.
You should be able to match each coagulopathy with the TEG that it produces.
Click on the area of the fibrinolysis pathway where tranexamic acid exerts its pharmacologic effect.
Plasmin degrades clots into fibrin degradation products.
Antifibrinolytic agents minimize clot breakdown by inhibiting the conversion of plasminogen to plasmin.
Click on the region of the nephron where MOST of the filtered sodium is reabsorbed.
Most of the filtered sodium (65 percent) is reabsorbed in the proximal tubule. Water follows sodium in the same proportion.
The loop of Henle reabsorbs 20 percent of sodium.
The distal tubule reabsorbs 5 percent of sodium.
The collecting duct reabsorbs 5 percent of sodium.
Aldosterone fine tunes sodium reabsorption in the principal cells in the distal tubules and collecting ducts.
Match each diuretic with its primary site of action.
Acetazolamide
Spironolactone
Bumetanide
Hydrochlorothiazide
Acetazolamide + A
Bumetanide + B
Hydrochlorothiazide + C
Spironolactone + D
Match each substance with the way it is handled by the kidney.
MORPHINE
SODIUM
GLUCOSE
CREATININE
Know the terms:
Filtration occurs when a substance is filtered at the glomerulus.
Reabsorption occurs when a substance moves from the ultrafiltrate to the peritubular blood.
Secretion occurs when a substance moves from the peritubular blood to the ultrafiltrate.
A: The substance is filtered, but there is no reabsorption or secretion. What is delivered to the ultrafiltrate is ultimately excreted. This commonly occurs with creatinine and other waste products.
B: The substance is filtered, and some of it is reabsorbed into the peritubular blood. This commonly occurs with electrolytes.
C: The substance is filtered, and all of it is reabsorbed into the peritubular blood. This commonly occurs with nutrients, such as glucose and amino acids.
D: The substance is filtered and an additional quantity is secreted into the ultrafiltrate. This commonly occurs with weak acids and weak bases (think drugs).
These concepts will be useful when you attempt the next question.
During the preoperative evaluation of a patient with congestive heart failure, you observe the following rhythm. Which of the following drugs are the MOST likely causes for this finding? (Select 2.)
Amiloride
Bumetanide
Spironolactone
Metolazone
Bumetanide
Metolazone
Explanation:
These are the types of questions that will net you big points on the NCE, because you have to connect several pieces of information together to arrive at the correct answer.
The U waves on this EKG suggest hypokalemia. Other possible EKG changes include flat or inverted T waves and ST depression. Other effects of hypokalemia include skeletal muscle weakness and enhanced effects of nondepolarizing neuromuscular blockers.
Now that we’ve established that K+ is low, we need to identify the diuretics that waste potassium. Only potassium sparing diuretics increase potassium reabsorption, so we can rule out spironolactone and amiloride. Therefore, bumetanide and metolazone are the most likely explanations for the patient’s hypokalemia.
The likelihood of digoxin toxicity is increased in the patient with hypokalemia. This condition increases digoxin binding inside the myocyte as well as increases its pharmacologic activity.
Click on the region of the nephron where indapamide exerts its diuretic effect.
Thiazide diuretics inhibit the Na-Cl transporter in the distal tubule. This reduces reabsorption of sodium, chloride, bicarbonate, and water.
Indapamide is a thiazide diuretic.
Unique side effects of thiazide diuretics you should know include:
Hyperglycemia - caution with diabetes
Hypercalcemia - caution with hypercalcemia
Hyperuricemia - caution with gouty arthritis
Click on the area of the nephron where acetazolamide alkalizes the urine.
Acetazolamide is a carbonic anhydrase inhibitor.
It alkalizes the urine by inhibiting bicarbonate reabsorption in the proximal tubule. Benefits of urine alkalization include:
Increased excretion of acidic drugs.
Maintenance of tubular flow in the patient with rhabdomyolysis (remember that myoglobin precipitates when the pH is less than 5.6.)
Click on the portal vein.
The portal vein is located between the splanchnic circulation and the liver.
The portal vein is a basin for blood that leaves the spleen, intestine, stomach, gallbladder, and pancreas and therefore carries a large nutrient load to the liver.
Because this blood has already oxygenated the splanchnic organs, it has a lower oxygen content when it arrives in the liver. This explains why it provides more blood flow than the hepatic artery, but it provides an equal amount of oxygen.
Click on the vessel that supplies 25% of hepatic blood flow.
The hepatic artery
Explanation:
The hepatic artery supplies 25 percent of the liver blood flow and 50 percent of the oxygen.
The portal vein supplies 75 percent of the liver blood and 50 percent of the oxygen.
Click on the region of the liver that is MOST susceptible to hypoxic injury.
Zone 3
Explanation:
Blood from the terminal branches of the hepatic artery and portal vein enter at the periphery of the lobule. Because of this, cells in zone 1 (near the periphery) are well oxygenated. Cells in zone 3 (near the central vein) receive the least amount of oxygen, and are therefore most susceptible to hypoxic injury. And as luck would have it, cells in zone 3 have the highest concentration of CYP450 enzymes.
Identify the statements that BEST describe the surgical procedure in the image. (Select 2.)
It is a definitive treatment for hepatorenal syndrome.
It is used to improve hepatic perfusion.
It improves esophageal varices.
It is commonly known as the TIPS procedure.
It improves esophageal varices
It is commonly known as the TIPS procedure
Explanation:
The TIPS procedure (transjugular intrahepatic portosystemic shunt) bypasses a portion of the hepatic circulation by shunting blood from the portal vein (hepatic inflow vessel) to the hepatic vein (hepatic outflow vessel).
This reduces portal pressure and minimizes back pressure on the splanchnic organs. In turn, it reduces the likelihood of bleeding from esophageal varices and reduces the amount of ascites.
Hemorrhage is a significant risk of the TIPS procedure.
Which of the following conditions is commonly associated with this EKG tracing?
Addison’s disease
Acromegaly
Conn’s syndrome
Myxedema
Conn’s syndrome
Primary hyperaldosteronism is called Conn’s syndrome.
Remember that aldosterone:
Increases Na+ AND water retention
Wastes K+ and H+
This EKG has a U wave, and you know that this suggests hypokalemia. This patient may also present with muscle weakness.
Click on the letter that corresponds to the region of the adrenal cortex where aldosterone is synthesized.
A = Capsule
B = Zona glomerulosa makes mineralocorticoids (aldosterone)
C = Zona fasciculata makes glucocorticoids (cortisol)
D = Zona reticularis makes androgenic hormones (estrogen & progesterone)
E. = Adrenal medulla makes catecholamines (Epi & NE)
You can remember the order of the zones with GFR.
Identify the MOST likely conditions that contribute to this fetal pattern. (Select 2.)
Umbilical cord compression
Preeclampsia
Fetal head compression
Maternal acidosis
Preeclampsia
Maternal acidosis
Explanation:
This fetal tracing shows late decelerations. Maternal acidosis and preeclampsia are causes of late decelerations.
Fetal head compression is consistent with early decelerations.
Umbilical cord compression is consistent with variable decelerations.
Click on the MOST common presentation of tracheoesophageal fistula.
Type C is the most common type of TEF.
Click on the region where a congenital diaphragmatic hernia is MOST likely to occur.
CDH most commonly occurs through the foramen of Bochdalek (usually on the left side).
Be sure to understand the orientation of this image. Imagine you are in the stomach looking up. You are NOT in the thorax looking down! The left side is correctly marked.
Which condition is MOST closely associated with this congenital defect?
Prematurity
Beckwith-Weidemann syndrome
Congenital heart disease
Trisomy 21
Prematurity
Gastroschisis is a congenital defect where the abdominal wall does not develop fully. There is no membrane covering (sac) to protect the viscera.
While this condition occurs later in fetal development, it is highly associated with prematurity. Other congenital anomalies are rare.
Click on the area that represents placenta increta.
The placenta normally implants itself onto the endometrium. Sometimes, however, the placenta invades the myometrium.
Accreta: The placenta invades the desidual layer of the endometrium and attaches to the surface of the myometrium (80 percent)
Increta: The placenta invades the myometrium (15 percent)
Percreta: The placenta extends beyond the uterus (5 percent)
After delivery, the placenta usually makes a clean break from the endometrium. If it invaded the uterine muscle, placental separation can lead to significant hemorrhage.
Abnormal placental implantation is more common in women with a history of cesarean section.
Click on the receptor present at the fetal motor endplate.
The fetal nicotinic receptor consists of a gamma, delta, beta, and 2 alpha sub units. Because they stay open longer when exposed to succinylcholine, there is a risk of hyperkalemia.
In the third trimester, continued development of the neuromuscular junction favors expression of the adult Nm receptor. The adult receptor is different, because the gamma subunit is replaced by an epsilon subunit (the pink receptor in the image).
What does the x-axis represent on the following illustration?
BMI
Total lung capacity
Age
Time
Age
Explanation:
The aged lung has a reduction in elastic recoil, which causes it to become overfilled with gas. This process increases residual volume, and the increase in RV explains why functional residual capacity is increased.
The reduction in elastic recoil causes the small airways to collapse during expiration. This is why closing capacity increases as we age. Consequences of increased CC include V/Q mismatch, decreased PaO2, and increased dead space.
Vital capacity decreases as a result of decreased lung elastic recoil, increased chest wall stiffness, and weakness of the respiratory musculature.
Total lung volume stays about the same. This is represented by the y-axis.
Which law is represented by the image?
Charles
Graham
Dalton
Henry
Dalton
Explanation:
Dalton’s law of partial pressures says that the total pressure is equal to the sum of the partial pressures exerted by each gas in the mixture.
P total = P1 + P2 + P3…
Click on the part of the oxygen delivery equation that exemplifies Henry’s law.
Henry’s law: At a constant temperature, the amount of gas that dissolves in solution is directly proportional to the partial pressure of that gas over the solution.
Henry’s law applied to oxygen solubility:
DO2 = CO x [(1.34 x Hgb x SpO2) + (PaO2 x 0.003)] x 10
Multiplying the PaO2 by oxygen’s solubility coefficient (0.003) allows us to calculate how much oxygen is dissolved in the blood.
Click on the image that represents the Bernoulli principle.
A patient caught in a house fire has suffered from a major burn (area in red). Estimate the total body surface area burned.
(Enter your answer as a percent)
37 percent (We accepted 36-38 percent)
Explanation:
The Rule of Nines divides the total body surface area into areas that represent 9 percent (or multiples of 9 percent).
Adult:
Head = 10 percent
Trunk = 36 percent
Arm = 9 percent
Leg = 18 percent
Perineum = 1 percent
Which food corresponds with the MOST pathologic form of fat accumulation?
Apple
Explanation:
Android obesity is often equated to the body shape of an apple. This type of fat accumulation is associated with an increased risk of ischemic heart disease, hypertension, DM, dyslipidemia, and death.
Gynecoid obesity is often equated with the body shape of a pear. This type of fat accumulation is associated with the development of joint disease and varicose veins.
We needed two other answer choices, and the watermelon and carrot looked tasty. And no, you won’t be tested on fruit on the NCE. We were just having a little fun.
Which positions cause the Frank Starling relationship to shift from point A to point B? (Select 2.)
Lithotomy
Sitting
Flexed lateral
Trendelenburg
Sitting
Flexed lateral
Explanation:
The awake patient has a variety of compensatory mechanisms designed to minimize the hemodynamic impact of position changes. General and neuraxial anesthesia attenuate these mechanisms, which increases the risk of hemodynamic instability during surgical positioning.
In positions where the head is above the level of the heart, venous pooling in the lower extremities reduces venous return. This is most likely to occur in the sitting, reverse-Trendelenburg, and flexed lateral positions.
Click on the image that BEST represents the Coanda effect.
Explanaton:
It’s easy to confuse the Bernoulli principal, Venturi effect, and Coanda effect, so let’s Examine all three.
Bernoulli’s principal describes the relationship between the pressure and velocity of a moving fluid (or gas).
If the fluid’s velocity is high, then the pressure exerted on the walls of the tube will be low.
If the fluid’s velocity is low, then the pressure exerted on the walls of the tube will be high.
The Venturi effect is an application of Bernoulli’s principal. As air flow in a tube moves past a point of constriction, the pressure at the constriction decreases (Bernoulli’s principal), and if the pressure inside the tube falls below atmospheric pressure, then air is entrained into the tube (Venturi effect).
Adjusting the diameter of the constriction allows for control of the pressure drop and the amount of air that is sucked into the tube. The key here is air entrainment!
The Coanda effect describes how a jet flow attaches itself to a nearby surface and continues to flow along that surface even when the surface curves away from the initial jet direction.
Click on the area that represents heat redistribution from the central compartment to the peripheral compartment.
When no attempts are made to maintain normothermia, heat transfer follows a triphasic curve.
Phase 1 = Heat redistribution from the core to periphery
Phase 2 = Heat transfer to the environment exceeds heat production
Phase 3 = Heat transfer to the environment parallels heat production
