Bonus Questions 2013 Flashcards
Here's a compilation of the q's from the 2014 class.
- You are about to place a femoral nerve block. Since you are in Punxsutawney, you are not allowed to use ultrasound guidance—you must rely on your expert knowledge of anatomy. You quickly refresh your memory by knowing:
a. The acronym NAVL (Nerve, Artery, Vein, and Ligament) starts medial and ends lateral
b. The nerve lies about 0.5-1 cm deeper and 1.5 cm lateral to the femoral artery
c. Knowing your anatomy will guarantee that you will achieve a perfect block 100% of the time.
d. After making your local skin wheel you should insert your needle in a cephalad angle (approximately 30 degrees)
e. After making your local skin wheel you should insert your needle in a caudal angle (approximately 30 degrees)
a. Answer b and e
i. Rationale: knowing b demonstrates proper order of NAVL anatomy (which runs lateral to medial, not the other way around), and e demonstrates an accurate understanding that angling your needle celphalad increases the likelihood that you will cover the femoral nerve before it bifurcates.
ii. Barash 6th edition, page 988 and 990
- While placing a femoral block, you decide to use a nerve stimulator. Accurate understanding of this is demonstrated by knowing:
a. Eliciting a strong knee twitch means you are right where you want to be and should dump your local anesthetic here
b. Immediately after inserting your needle you should start the nerve stimulator at 4 mA
c. After eliciting a strong leg reflex with the nerve stimulator reduced down to 0.3 mA, you should aspirate, if no blood, inject local anesthetic (in 5 ml increments)
d. You notice a strong leg reflex with the nerve stimulator at 0.2 mA, therefore you should insert your needle approximately 2-3 mm closer to the nerve
i. Rationale: Answer c demonstrates accurate knowledge of proper reflex (not just knee but total leg reflex), as well as proper understanding of nerve stimulator mechanics and local anesthetic injection technique
ii. Barash 6th edition, page 957
- You are working in a remote hospital about to place an interscalene block. The resources in this location are limited. They do, however, have a room designated for block placement. Before you begin to place the block you ensure that you have the following in the room before you start (select 4):
a. Suction
b. Emergency airway supplies
c. Oxygen
d. Sufficient lighting
e. Sedation medications
f. Lipid rescue
g. Difficult airway cart
i. Rationale: Answers a-d demonstrates understanding of the proper equipment needed to place a block. Sedation medications are nice, lipid rescue should be nearby, and a difficult airway cart great to have nearby—but none of these are required.
ii. Barash 6th edition, page 956
- You place a femoral and popliteal nerve block prior to a total knee arthroplasty using anatomy and nerve stimulator technique. After 10 minutes the patient reports that he can still flex/extend his leg and states that he doesn’t “feel much different” than he did prior to the block. This report means that you should:
a. Try the block again—this time using ultrasound
b. Change your anesthetic plan to a general anesthetic
c. Check the patient again in about 1-2 minutes to see if his block is working then
d. Wait another 10-20 minutes before you rule out the block
i. Rationale: Answer D. Blocks can take about 20-30 minutes to set up. Blocking again may be unnecessary plus run the risk of local anesthetic toxicity. Changing the anesthetic plan to a general may be premature. Checking again in 1-2 minutes is still not enough time to fully allow for “soak time.”
ii. Barash 6th edition, page 956
- While using a nerve stimulator and ultrasound to place an interscalene block, it is usually helpful to:
a. Mark your site after a scout look with the ultrasound, use sterile gloves, mask, prep with proper cleaning solution, drape, and use ultrasound transducer gel.
b. Same as above except use clean gloves vs sterile gloves since this is only a clean technique.
c. Use an “in-plane” technique when lining up your landmarks and needle (longitudinal)
d. Use an “out-of-plane” technique when lining up your landmarks and needle (transverse)
e. Both a and c
f. Both a and d
i. Rationale: Sterile technique minimizes the risk of infection. Although an out-of-plane technique can be utilized for compact areas, it is most helpful to use an in-plane technique when placing a block so you can visualize your needle as it approaches the needle as this technique allows visualization of vital strictures (lungs, major vessels, etc.)
ii. Barash 6th edition, page 958
- To adequately prevent pain from an arm tourniquet, which of the following nerve blocks should be performed to augment an axillary brachial plexus block?
a. Musculocutaneous, medial brachial cutaneous, and intercostobrachial nerve blocks
b. Musculocutaneous and medial brachial cutaneous nerve block
c. Musculocutaneous and intercostobrachial nerve blocks
d. Ulnar and Radial nerve blocks
Answer A.
These 3 nerves may need to be blocked separately as they exit the brachial
Plexus sheath high in the axilla.
Nagelhout page 1087
- All of the following local anesthetics exert a vasodilatory effect except for:
a. Ropivacaine
b. Lidocaine
c. Prilocaine
d. Bupivacaine
Answer A
Ropivacaine and cocaine are the only LA’s that produce vasoconstriction.
Morgan and Mikhail Pages 271-274
- By inserting a needle 2 cm medial and caudal to the anterior superior iliac spine and injecting 10-15 ml of local anesthetic after the needle penetrates the fascia lata, you would be attempting to block which nerve?
a. Obuturator
b. Lateral femoral cutaneous
c. Musculocutaneous
d. Sciatic
Answer B
The lateral femoral cutaneous nerve emerges underneath the inguinal ligament And becomes superficial inside the fascia lata near the anterior superior anterior superior iliac spine
Morgan and Mikhail 346-347
- The blood supply to the spinal cord and nerve roots arises from:
a. Paired anterior and paired posterior spinal arteries
b. A single anterior and paired posterior arteries
c. Paired anterior arteries and a single posterior artery
d. A single anterior and a single posterior artery
Answer B.
The blood supply to the spinal cord is derived from a single anterior and paired posterior arteries. The anterior spinal artery is formed from the vertebral artery and supplies the anterior 2/3 of the cord while the posterior spinal arteries are derived from the posterior inferior cerebellar arteries and supply the posterior 1/3 of the spinal cord.
Morgan and Mikhail 294-295
- A burn patient exhibits signs of inhalation injury and possible carbon monoxide poisoning. All of the following regarding carbon monoxide are true except:
a. It has a greater infinity for hemoglobin than oxygen
b. It can result in metabolic acidosis
c. It impairs mitochondrial function
d. It shift the oxyhemoglobin dissociation curve to the right
Answer D
Carbon monoxide has an affinity for hemoglobin that is 200 times greater than that of oxygen, impairs mitochondrial function, uncouples oxidative phosphorylation and reduces ATP production resulting in metabolic acidosis, and shifts the oxyhemoglobin dissociation curve to the left, impairing the unloading of oxygen to the tissues. In addition, it acts as a direct myocardial toxin and can prevent survival in resuscitation efforts during cardiac arrest. Barash Page 909
- Superiorly the epidural space extends from the _____ to the ______.
a. Foramen magnum, sacral hiatus
b. Foramen magnum, cauda equina
c. C2, L5
d. C2, sacral hiatus
Answer: A. Superiorly, the epidural space extends to the foramen magnum, where dura is fused to the bse of the skull. Caudally it ends at the sacral hiatus.
James Duke – Anesthesia Secrets. Fourth Edition. Page 458.
- What is an absolute contraindication to spinal anesthesia?
a. Sepsis
b. Chronic back pain
c. Intracranial hypertension
d. Progressive neurologic disease such as multiple sclerosis
Answer: C. Absolute contraindications include local infection at the puncture site, bacteremia, severe hypovolemia, coagulopathy, severe stenotic valvular disease, intracranial hypertension and patient refusal. Relative contraindications include progressive neurologic disease such as multiple sclerosis, low back pain, and sepsis.
James Duke – Anesthesia Secrets. Fourth Edition. Page 454.
- What is the leading cause of morbidity and mortality in the burn patient?
a. Hypovolemic shock
b. Cardiogenic shock
c. Renal failure
d. Infection
Answer: D. Infection in the burn patient is a leading cause of morbidity and mortality and remains one of the most demanding concerns for the burn team. As burn wound size increases, bloodstream infection increases dramatically secondary to exposure to IV catheters and burn wound manipulation-induced bacteremia.
James Duke – Anesthesia Secrets Fourth Edition. Pg 383.
- Electroconvulsive therapy can be used safely in all patients except:
a. Pts with a cardiac pacemaker
b. Pts with an implantable cardiodefibrillator
c. Parturients
d. Recent MI
Answer: D. ECT should be used very cautiously if at all when the effects on cerebral blood flow, ICP, HR, and BP may prove problematic to the patient. Pts with unstable cardiac disease and those with cerebral space occupying lesions are at risk of complications. ECT has been used safely in pts with cardiac pacemaker or implantable cardiodefibrillators and during pregnancy. James Duke – Anesthesia Secrets. Fourth Edition. Page 523.
- Your patient is presenting for a toe amputation and has a known ester allergy (rash, bronchospasm). An ankle block is the best anesthetic option for him due to severe cardiovascular issues and COPD. What would you do?
a. Tell him that a nerve block is not an option due to his proven ester allergy, and his surgery will be very high risk under general anesthesia.
b. Proceed with injecting an ester because you know that true allergies to local anesthetics are rare and his “allergy” was most likely systemic toxicity.
c. Administer an ankle block using an amide local anesthetic.
d. Tell him that he is not a surgical candidate.
Answer: C. There is no cross-sensitivity between classes of local anesthetics. Therefore patients known to be allergic to ester local anesthetics could receive amide local anesthetics. However, caution is still warranted in case the patient is allergic to the preservative that may be common to both classes of drugs.
James Duke – Anesthesia Secrets. Fourth Edition. Page 106.
- A patient presents with a fracture to the third metatarsal (middle toe) of the right foot. Which nerve would need to be blocked along with the medial plantar nerve to provide adequate anesthesia to the operative site?
a. Sural Nerve
b. Deep Peroneal Nerve
c. Superficial Peroneal Nerve
d. Saphenous Nerve
Answer: C
Rationale: The superficial peroneal nerve provides dorsal coverage of the third forth and fifth metatarsals.
Reference: Miller- Page 293 Figure 18-11, Innervation of the lower extremities.
- Hypotension after spinal anesthesia occurs from: (Choose Two)
a. Parasympathetic blockade which increases venous return
b. Sympathetic blockade which decrease venous return
c. Sympathetic blockade which decreases SVR
d. Parasympathetic blockade which increases SVR
Answer: B and C
Rationale: Spinal Anesthesia blocks the sympathetic nervous system lowering the patient’s blood pressure by decreasing venous return and decreasing systemic vascular resistance.
Reference: Miller- Page 270
- A patient has a lesion of their spine at the level of T1. All of the following nerves could be compromised EXCEPT:
a. Musculocutaneous
b. Axillary
c. Radial
d. Median
e. Ulnar
Answer: A
Rationale: The musculocutaneous nerve is innervated from C 5, 6, 7. The remaining options could possibly have some innervation from T1 and could therefore be effected.
Reference: Miller- Page 288 Figure 18-5, The Brachial Plexus.
- After epidural catheter placement, your patient experiences bilateral lower extremity motor loss prior to any drug injection. You begin to suspect your needle contacted which anatomic region during placement?
a. Spinal nerve rootlets of the Cauda Equina
b. The Artery of Adamkiewicz
c. The Dura
d. Epidural vein
e. None of the above
Answer: B
Rationale: Accidental damage to the Artery of Adamkiewicz during epidural placement can occur. This causes characteristic bilateral lower extremity motor loss (anterior spinal artery syndrome).
Reference: Miller- Page 261
- To what dermatome level would the spinal height need to reach for surgery on the appendix or lower abdomen?
a. T 4 (nipple)
b. T 6-7 (xiphoid process)
c. T 10 (umbilicus)
d. L 1-3 (Inguinal ligament)
Answer: B
Rationale: T 4 is adequate but higher than necessary for appendix or lower abdominal surgery. T 6-7 is the proper choice for spinal height in this region. T 10 and L 1-3 are not sufficient height to anesthetize the desired surgical site.
Reference: Miller- Page 268, Table 17-2, Sensory Level of Anesthesia Necessary for surgical procedures.
- If the oculocardiac reflex is suspected during ophthalmic surgery what is the first step the anesthetist should take to alleviate the symptoms?
a. Administer 1 mg of atropine IV
b. Administer .01 mg/kg epinephrine IV
c. Ask the surgeon to stop the surgical stimulus
d. Prepare for immediate cardioversion
Answer C
“If a cardiac dysrhythmia appears, initially the surgeon should be asked to cease operative manipulation. Next, the patient’s anesthetic depth and ventilatory status are evaluated. Commonly, heart rate and rhythm return to baseline within 20 seconds after institution of these measures.”
(Barash 6th Edition pg. 1327)
- Bradycardia associated with the oculocardiac reflex is
a. Less likely to occur with repeated stimulation during ophthalmic surgery
b. More likely to occur with repeated stimulation during ophthalmic surgery
c. Not associated with ophthalmic surgery
d. Not clinically significant and can be ignored
Answer A
“…with repeated manipulation, bradycardia is less likely to recur, probably secondary to fatigue of the reflex arc at the level of the cardioinhibitory center.”
(Barash 6th Edition pg. 1327)
- Gynecoid (peripheral) obesity is associated with (Choose 2)
a. Increased oxygen consumption and increased incidence of cardiovascular disease.
b. Less metabolically active adipose tissue so it is less closely associated with cardiovascular disease.
c. Adipose tissue that is located predominantly in the upper body.
d. Adipose tissue that is located predominantly in the hips, buttocks, and thighs.
Answers B and D
“Varying pathophysiologic consequences are associated with the anatomic distribution of body fat. In android (Central) obesity, adipose tissue is located predominantly in the upper body (truncal distribution) and is associated with increased oxygen consumption and increased incidence of cardiovascular disease. Visceral fat is particularly associated with cardiovascular disease and left ventricular dysfunction. In Gynecoid (peripheral) obesity, adipose tissue is located predominantly in the hips, buttocks, and thighs. This fat is less metabolically active so it I less closely associated with cardiovascular disease.
(Barash 6th Edition pg. 1230
- Perioperative monitoring during off-site anesthesia must include which of the following:
a. Pulse oximetry, invasive monitoring, EKG, constant blood pressure
b. Intermittent blood pressure monitoring, EKG, end-tidal CO2 invasive monitoring
c. Pulse oximetry, heart rate, intermittent blood pressure monitoring, EKG, end-tidal CO2, Temperature monitoring
d. EKG, Cerebral oxygenation, Temperature monitoring, EKG, pulse oximetry
Answer C
“Perioperative monitoring must adhere to the ASA standards for basic anesthetic monitoring. These include continuous monitoring of heart rate and oxygen saturation, intermittent noninvasive blood pressure monitoring, end-tidal CO2 monitoring and the capacity for both temperature monitoring and continuous electrocardiogram.”
(Barash 6th Edition pg. 854)
- Using the “Rule of 9s” calculate the percent burn for a patient with second and third degree burns to his entire anterior torso and a circumferential burns to his right arm.
a. 36%
b. 18%
c. 9%
d. 27%
Answer D
“The size of the burned area as a fraction of the total body surface area (TBSA) is estimated by the “rule of nines.” In an adult, the head contributes to 9%; the upper extremities, 18%; the trunk, 36%; and the lower extremities, 36% of the TBSA.”
(Barash 6th Edition pg. 908-909)
- You plan to give an interscalene block to a 67 y.o. male with CAD, emphysema, severe OA, and BPH, who is undergoing Rt ORIF of the shoulder. Pt has been cleared by his cardiologist, has normal PFTs and states he is able to walk 2 flights of stairs with moderate DOE. You know that the incidence of diaphragmatic dysfunction after performing an interscalene block approaches:
a. 25%
b. 50%
c. 75%
d. 100%
Answer d. 100% (Brock-Utne, 2011, p. 25)
Studies have found phrenic nerve block to occur in 100% of interscalene block. The phrenic nerve innervates the diaphragm.
You have been called emergently to give an anesthetic to a 45 yo morbidly obese diabetic undergoing and I & D of his left heel after he stepped on a thumb tack. The pt has a history of difficult airway and severe PONV. After talking with the patient and his family you all agreed that Spinal anesthesia is the best option. You know that the patient is slightly acidotic, with a serum pH of 7.32. You anticipate that this finding has the possibility to affect your Bupivacaine spinal in the following way:
a. Acidic pH decreases the potency of Bupivacaine
b. Acidic pH increases the potency of Bufpivacaine
c. Acidic pH shortens the onset time of Bupivacaine
d. Acidic pH prolongs the onset time of Bupivacaine
Answer d. Acidic pH prolongs the onset time of Bupivacaine (Duke, 2011, p. 107)
The degree of ionization, or the pKa, influences the onset time of local anesthetics. Potency is determined by lipid solubility not pKa. Because local anesthetics are all weak bases, increasing the acidity of the pH would cause more of the local anesthetic to become ionized, thereby prolonging the time of onset.
Before performing an intercostal nerve block for pain management for a patient with 3 broken ribs and flail chest, you understand that comparing systemic absorption of local anesthetic between different regional blocks,
a. Intercostal is the most likely to be rapidly systemically absorbed.
b. Intercostal is less likely than paracervical to be rapidly absorbed.
c. Intercostal is only more likely than intravenous in terms of rapid systemic absorption.
d. Intercostal is less likely than brachial plexus blocks in terms of rapid systemic absorption.
Answer a. Intercostal is the most likely to be rapidly systemically absorbed. (Duke, 2011, p. 108)
From fastest to slowest, IV > Tracheal > Intercostal > Caudal > Paracervical > Epidural > Brachial Plexus > Subarachnoid > Subcutaneous. However, in terms of regional anesthetic procedures, the most rapidly absorbed is the intercostal block. We do not typically use IV or transtracheal administration for regional anesthesia. Bier blocks work by transudation of local anesthetic out of the circulation into the third space compartment, and a major concern is the avoidance of rapid systemic absorption.
While performing a single-shot axillary block, you find palpation of the axillary artery pulse difficult, so you elect to use a nerve stimulator to ascertain nerve location by motor stimulation. The first stimulation that you see when inserting the needle is flexion of the elbow (or stimulation of the coracobrachialis muscle), you know from this that:
a. You are in the neural sheath and should inject.
b. You are outside the neural sheath and should redirect the needle downward and more superficially.
c. You have directed the needle too inferiorly and are stimulating the radial artery, you should inject and then redirect more superiorly.
d. You should decrease the intensity of the output current, you are in the neural sheath, but stimulation has spread due to the inaccurate settings.
Answer b. You are outside the neural sheath and should redirect the needle downward and more superficially. (Hadzic, 2007, pp. Ch 28, Axillary Brachial Plexus Block exact page unkown)
The rationale for using the single-shot technique is that because of the presence of a neurovascular sheath, containing at the level of the axilla, the median, ulnar, and radial nerves, injection of LA in this sheath should sufficiently spread to anesthetize all three. Stimulation of the coracobrachialis or musculocutaneous nerve results in flexion of the elbow, so that you are too superior to the axillary portion of the neurovascular sheath. Radial artery stimulation would be evidenced by extension of the wrist and hand.
You are performing a femoral nerve block with nerve stimulation to aid placement. The initial response to the output current is the stimulation of the Sartorius muscle. You know that this means:
a. The needle tip has stimulated the main trunk of the femoral nerve, so you should accept this and inject your local anesthetic .
b. The needle tip is slightly anterior and medial to the main trunk of the femoral nerve, so you should redirect the needle laterally and advance deeper.
c. The needle is inserted too superficially, so you should push deeper until contacting hip or the superior ramus of the pubic bone, and only then inject.
d. You should not get a muscle twitch with the femoral nerve block, so you should withdraw, palpate for the femoral artery, and insert so as to pass through the artery then inject.
Answer b. The needle tip is slightly anterior and medial to the main trunk of the femoral nerve, so you should redirect the needle laterally and advance deeper. (Hadzic, 2007, pp. Ch 35 Femoral Nerve Block, exact page unkown)
The sartorious and its innervation are superficial and medial to the femoral nerve, what you are looking for is patellar snap. Contacting bone simply means you have gone too deep, and you should not inject here. If there is no muscle twitch, then you are probably far too lateral or medial, follow a more systematic approach to locating the artery and other landmarks.
The “snap” felt just before entering the epidural space represents passage through which ligament?
a. Anterior longitudinal ligaments
b. Posterior longitudinal ligaments
c. Ligamentum flavum
d. Supraspinous ligament
Answer C
(Barash, ed 5, pp698-699)
The structures that are traversed by a needle placed in the midline prior to the epidural space are as follows: skin, subcutaneous tissue, supraspinous ligament, interspinous ligament, and ligamentum flavum. The flavum is tough and dense and a change in the resistance to advancing the needle is often perceived and to many feels like a snap.
. Severe hypotension associated with high spinal anesthesia is caused by primarily
a. Decreased systemic vascular resistance
b. Decreased cardiac output secondary to bradycardia
c. Decreased cardiac output secondary to decreased preload
d. Decreased cardiac output secondary to decreased myocardial contractility
Answer C
With a high spinal, the decrease in venous dilation is the predominant cause of hypotension. (Barash, ed 5, pp708-709)
Para-aminobenzoic acid is a metabolite of
a. Mepivicaine
b. Ropivicaine
c. Procaine
d. Bupivicaine
e. Prilocaine
Answer C
Paba is an active metabolite of the ester-type local anesthetics. Esters are metabolized by the enzyme psuedocholinesterase. Paba is a metabolite breakdown product of ester anesthetics and is responsible for allergic reactions in some individual. (Stoelting pp180-189)
Which of the following local anesthetics undergoes the least hepatic clearance?
a. Lidocaine
b. Bupivicaine
c. Chloroprocaine
d. Prilocaine
Answer C (source is Barash, page 462) Commonly injected local anesthetics are divided chemically into two groups: esters and amides. The esters include procaine, chloroprocaine, and tetracaine. The amides are lidocaine, mepivicaine, prilocaine, buipivicaine, levobupivicaine, etidocaine, and ropivacaine. The esters undergo plasma clearance by cholinesterases and have relatively short half-lives, whereas the amides undergo hepatic clearance and have longer half lives
A 36-year-old female patient is undergoing a thyroidectomy under a deep cervical plexus nerve block. Which of the following complications would be LEAST likely with this block?
a. Horner’s syndrome
b. Subarachnoid injection
c. Blockade of the spinal accessory nerve
d. Blockade of the recurrent laryngeal nerve
Answer C
Complications of deep cervical plexus block include injection of the local anesthetic into the vertebral artery, subarachnoid space, or epidural space. Other nerves that may be anesthetized include the phrenic nerve (which is why bilateral deep cervical plexus blocks should be performed with caution, if at all), and the recurrent laryngeal nerve. (Barash ed 5 p723)