NBCRNA CRNA Exam Questions

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181.

Rare instances of transient blindness following surgery have been associated with which of the following irrigating fluids used in transurethral resection of the prostate (TURP)?

  • Glycine

  • Sorbitol

  • Dextrose

  • Mannitol

Correct answer: Glycine

Glycine has been implicated in rare instances of transient blindness following transurethral resection of the prostate (TURP). It is a known inhibitory neurotransmitter in the central nervous system. Glycine gains entry into the intravascular space and is metabolized in the portal bed and kidneys via oxidative deamination. The brain also contains a glycine cleavage enzyme system that splits glycine into carbon dioxide and ammonia. The increase in serum ammonia levels dissipates the current, preventing both cutting and coagulation. It is mainly used for irrigation with the bipolar resectoscope but can cause hyperchloremic acidosis because of excessive chloride content.

The use of large amounts of sorbitol or dextrose irrigating solutions can lead to hyperglycemia. The use of mannitol can lead to intravascular volume expansion and may exacerbate fluid overload.

182.

Which of the following medications may contribute to the development of hyperthyroidism?

  • Amiodarone

  • Amlodipine

  • Propylthiouracil

  • Propranolol

Correct answer: Amiodarone

Hyperthyroidism may result from several causes, including the administration of certain drugs, such as iodinated contrast dye or amiodarone. Other non-drug related causes include Graves disease, toxic multinodular goiter, thyroiditis, cancer of the thyroid, tumors of the pituitary gland, struma ovarii, and disorders specific to pregnancy. 

Both propranolol and propylthiouracil are used in the treatment of hyperthyroidism.

The use of amlodipine does not cause hyperthyroidism.

183.

The treatment of hypercalcemia includes all the following except:

  • Brisk diuresis with a loop diuretic followed by rehydration with saline

  • Rehydration with saline followed by furosemide

  • Following rehydration and diuresis, treatment with bisphosphonates or calcitonin if needed

  • Glucocorticoids in the presence of vitamin D-induced hypercalcemia

Correct answer: Brisk diuresis with a loop diuretic followed by rehydration with saline

Premature diuretic therapy before rehydration can aggravate hypercalcemia because of additional volume depletion. The most effective initial treatment is rehydration followed by a brisk diuresis with the administration of an intravenous saline infusion and a loop diuretic to accelerate calcium excretion.

Although hydration and diuresis may remove the potential risk of cardiovascular and neurological complications of hypercalcemia, the serum calcium usually remains elevated above normal. Additional therapy with a bisphosphonate or calcitonin may be required to further lower the serum calcium. Additional treatment depends on the underlying cause and may include glucocorticoids in the presence of vitamin D-induced hypercalcemia, such as granulomatous disease states.

184.

Which of the following statements is true about blood transfusions?

  • They can cause an increase in serum lactate

  • They can cause an increase in serum calcium levels

  • They can cause an increase in serum pH levels

  • They can cause an increase in 2,3, diphosphoglycerate (2,3-DPG)

Correct answer: They can cause an increase in serum lactate

Lactic acid increases during the storage of donated blood as the blood cells continue metabolic processes via anaerobic pathways.

Blood transfusions can cause a decrease in serum calcium levels, a decrease in serum pH levels, and a decrease in 2,3-DPG.

185.

Which of the following considerations is most important when using nitrous oxide during otolaryngological surgery?

  • Nitrous oxide can affect middle ear pressures

  • Nitrous oxide is absolutely contraindicated during otolaryngological surgery

  • Nitrous oxide use during otolaryngological surgery may cause delayed postsurgical recovery

  • There are no specific considerations when using nitrous oxide during otolaryngological surgery

Correct answer: Nitrous oxide can affect middle ear pressures

Nitrous oxide is more soluble than nitrogen in the blood, diffusing into air-filled cavities faster than nitrogen. This can lead to increased middle ear pressure, which may be problematic during otolaryngological surgery. While extra precautions, such as discontinuing nitrous oxide use prior to the application of an eardrum graft, may be necessary, nitrous oxide is not absolutely contraindicated during otolaryngological surgeries. Nitrous oxide use during otolaryngological surgery does not necessarily cause delayed postsurgical recovery.

186.

Which of the following statements about innervation of the heart is true?

  • Parasympathetic fibers are primarily responsible for innervation of the atria.

  • Innervation of the sinoatrial node comes via the left vagus afferent fibers.

  • Acetylcholine acts on specific cardiac receptors to produce positive inotropic effects.

  • Parasympathetic fibers are widely distributed throughout the heart.

Correct answer: Parasympathetic fibers are primarily responsible for innervation of the atria.

Parasympathetic fibers primarily innervate the atria and conducting tissues of the heart.

The innervation of the sinoatrial node comes via the right vagus efferent fibers (the parasympathetic nervous system). The left sympathetic (afferent) and vagus nerves primarily affect the atrioventricular node. Norepinephrine release (rather than the action of acetylcholine) produces positive inotropic effects. Acetylcholine causes negative chronotropic, dromotropic, and inotropic effects. Sympathetic fibers, rather than parasympathetic fibers, are more widely distributed throughout the heart.

187.

The thirst control center is located in which of the following?

  • Hypothalamus

  • Anterior pituitary

  • Posterior pituitary

  • Amygdala

Correct answer: Hypothalamus

The thirst control center is located in the hypothalamus of the brain. Osmoreceptors in the lateral preoptic area of the hypothalamus are very sensitive to changes in extracellular osmolality. Activation of these neurons when extracellular osmolality increases causes thirst and leads an individual to drink water. Conversely, hypoosmolality suppresses thirst.

188.

Which of the following statements is true about colloids?

  • They are used in combination with crystalloids when fluid replacement needs exceed 3 to 4 liters

  • Colloid particles break down into smaller pieces in water as crystalloids do

  • They are used to replace blood loss at a 3:1 ratio

  • The oncotic pressure in colloids helps to disperse the solution into the interstitium

Correct answer: They are used in combination with crystalloids when fluid replacement needs exceed 3 to 4 liters

When fluid replacement needs are greater than 3 to 4 liters, colloids are usually given, along with crystalloids.

Colloids do not break down into smaller pieces in water as crystalloids do. They consist of high-molecular-weight substances that help to keep the solution intravascularly; they do not easily pass through capillary pores and are not easily dispersed into the interstitium. Colloids are used to replace blood at a 1:1 ratio. Crystalloids are given at a 3:1 ratio.

189.

What effect is lithium most likely to have on the minimum alveolar concentration (MAC)?

  • Decreased MAC

  • Increased MAC

  • No effect on MAC

  • Unpredictable effect on MAC

Correct answer: Decreased MAC

Lithium is an example of a nonanesthetic medication that can result in a lowered minimum alveolar concentration (MAC). Lithium is not likely to increase MAC or have no effect on MAC. The effect of lithium on MAC is predictable.

190.

A patient who is being asked to consent to the use of blood products asks about the risk of liver infections. Knowledge of which fact should guide the CRNA's answer?

  • There is about a 1 in a million risk of getting hepatitis from a blood transfusion

  • There is about a 1 in 100 million risk of getting hepatitis from a blood transfusion

  • There is about a 1 in 10,000 risk of getting hepatitis from a blood transfusion

  • There used to be a risk of getting hepatitis from a blood transfusion but this risk is no longer present

Correct answer: There is about a 1 in a million risk of getting hepatitis from a blood transfusion

The risk of developing hepatitis that is transmitted by blood transfusion is about 1 in a million. While modern blood collection practices have significantly reduced this risk, the risk is still present, albeit minimal.

191.

Which of the following types of receptors bind to acetylcholine?

  • Nicotinic and muscarinic

  • Cholinergic and adrenergic

  • Muscarinic and adrenergic

  • Adrenergic and nicotinic

Correct answer: Nicotinic and muscarinic

Acetylcholine is released by cholinergic neurons and norepinephrine is released by adrenergic neurons. There are two types of cholinergic receptors, nicotinic and muscarinic, both of which bind to acetylcholine.

192.

Which of the following conditions is most likely to cause a vitamin K deficiency?

  • Fat malabsorption

  • Bleeding disorder

  • Liver disease

  • Hypokalemia

Correct answer: Fat malabsorption

Fat malabsorption can affect vitamin K levels, as vitamin K is a fat-soluble vitamin. Vitamin K deficiency can cause bleeding disorders, not the other way around. Liver disease and hypokalemia do not have a significant effect on vitamin K levels.

193.

Which of the following conditions is a contraindication to the use of metoclopramide?

  • Parkinson's disease

  • Severe nausea

  • Intractable depression

  • Crohn's disease

Correct answer: Parkinson's disease

Metoclopramide causes a mild dopamine receptor-blocking effect, potentially exacerbating the symptoms of Parkinson's disease. For this reason, metoclopramide is generally contraindicated in patients with Parkinson's disease. Metoclopramide is also contraindicated with intestinal obstruction. Severe nausea, intractable depression, and Crohn's disease are not contraindications to using metoclopramide.

194.

Which of the following statements is true about myasthenia gravis?

  • Episodes of frequent vomiting may lead to an exacerbation of symptoms.

  • It primarily affects smooth, involuntary muscles.

  • A patient with myasthenia gravis should never receive succinylcholine to facilitate endotracheal intubation.

  • The antibiotic of choice to treat upper respiratory tract infections in myasthenia gravis patients is levofloxacin.

Correct answer: Episodes of frequent vomiting may lead to an exacerbation of symptoms.

Hypokalemia (low levels of potassium in the blood) caused by diuretics or frequent vomiting can exacerbate Myasthenia Gravis (MG) symptoms. Other reasons for exacerbations of MG symptoms include the following:

  • Emotional stress
  • Exposure to extreme temperatures
  • Fever
  • Illness (respiratory infection, pneumonia, tooth abscess)
  • Some medications (muscle relaxants, anticonvulsants, and certain antibiotics)

MG affects voluntary (not involuntary) muscles, such as the ocular and pharyngeal muscles. Succinylcholine can be used to facilitate endotracheal intubation; however, the results are variable. Resistance to succinylcholine may be present, and the effects of succinylcholine can be prolonged. The fluoroquinolones, such as levofloxacin and ciprofloxacin, have been associated with the worsening of symptoms of MG and carry a black box warning issued by the United States Food and Drug Administration.

195.

Which of the following is most important to have in place for a patient who is undergoing anesthesia for the resection of an abdominal aortic aneurysm?

  • Arterial line monitoring

  • Frequent noninvasive blood pressure monitoring

  • Central venous pressure monitoring

  • Continuous cardiac output monitoring

Correct answer: Arterial line monitoring

Intraarterial pressure monitoring is essential for anyone undergoing resection of an abdominal aortic aneurysm. Noninvasive blood pressure monitoring should not be used as it is less reliable and does not provide live, continuous information about intraarterial pressures. While central venous pressure monitoring and continuous cardiac output monitoring are also likely to be used for these patients, they are not as important as continuous intraarterial pressure monitoring.

196.

All the following induction drugs reduce cerebral metabolic rate except:

  • Ketamine

  • Propofol

  • Thiopental

  • Midazolam

Correct answer: Ketamine

Ketamine is likely to have no effect on (or may slightly increase) cerebral metabolic rate.

All other anesthetic agents (including propofol, thiopental, and midazolam) cause cerebrovascular constriction.

197.

The use of the flush valve during the inspiratory cycle has the potential to cause which of the following?

  • Lung barotrauma

  • Loss of circuit volume

  • A flood of nitrous oxide filling the circuit

  • A flood of volatile gases filling the circuit

Correct answer: Lung barotrauma

The oxygen flush valve provides a high flow of oxygen directly to the common gas outlet, which bypasses the flowmeters and vaporizers. It is used to quickly refill or flush the breathing circuit. Because oxygen supplied at this location may be at a line pressure of 45 to 55 psig, there is a very real danger of lung barotrauma. The flush valve must be used cautiously whenever a patient is connected to the breathing circuit.

Using the flush valve does not result in loss of circuit volume or a flood of other gases filling the circuit.

198.

A 38-year-old male veteran has been diagnosed with posttraumatic stress syndrome. Which of the following nerve blocks has been successfully used in clinical research to treat this disorder?

  • Stellate ganglion block

  • Occipital nerve block

  • Celiac plexus block

  • Lumbar sympathetic block

Correct answer: Stellate ganglion block

In addition to providing anesthesia and analgesia both within the operating suites and non-operating room anesthesia (NORA) locations, the anesthesia provider is also expected to manage, or assist in the management of, patients who suffer from chronic pain. Chronic pain may result from a variety of etiological factors, including injury, disease process, previous surgery, or traumatic events. Nerve blocks may be preferable in some of these situations. 

The stellate ganglion nerve block is typically used to treat the pain of complex regional pain syndrome (CRPS) of an upper extremity, neuropathy resulting from herpes zoster, or neuritis that may develop after radiation treatment. Stellate ganglion nerve block has been successfully used to treat posttraumatic stress syndrome during clinical research.

Occipital nerve block is used in the treatment of migraines and chronic headaches. Celiac plexus block is an effective treatment in patients who have pancreatic or other abdominal tumors. Lumbar sympathetic block is used to treat neuropathic-type pain of the lower extremities.

199.

Which of the following is likely to be increased when nitroglycerin is administered? (Select 2.)

  • Cerebral blood flow 

  • Intracranial pressure

  • Mean arterial pressure

  • Systolic blood pressure

  • Temperature

Nitroglycerin leads to the dilation of intracranial blood vessels, increasing cerebral blood flow and intracranial pressure. Systemic vasodilatation decreases mean arterial pressure and systolic blood pressure. Temperature is not typically meaningfully affected by nitroglycerin administration.

200.

Which of the following drugs, if administered during a cholangiogram, can result in a false-positive result?

  • Morphine

  • Glucagon

  • Halothane

  • Naloxone

Correct answer: Morphine

All opioids can potentially cause spasm of the Sphincter of Oddi and increase biliary pressure. The use of intravenous opioids (such as morphine, fentanyl, meperidine, butorphanol, and nalbuphine) can induce biliary colic or result in false-positive cholangiograms.

Halothane, naloxone, and glucagon are reported to relieve opioid-induced biliary spasms.