True Learn: Neuroscience & Neuromuscular Flashcards
A 25-year-old, 75-kg presents for a craniotomy after a motor vehicle accident 2 hours ago and sustaining a traumatic brain injury. An external ventricular drain was placed in the emergency department. Currently, his intracranial pressure is reading 40 mmHg. Which of the following anesthetic techniques is MOST appropriate in this patient?
A. 1.0 MAC of isoflurane
B. Controlled hypotension with mean arterial pressure between 60 and 70 mmHg
C. Hyperventilation to an EtCO2 of 25 mmHg
D. Total intravenous anesthesia with propofol and fentanyl
D. Total intravenous anesthesia with propofol and fentanyl
During a knee arthroplasty revision under general anesthesia, the thigh tourniquet is left inflated uninterrupted for over 4 hours. The lower leg is then found to be swollen and painful the next morning after surgery. The urinary catheter is draining dark urine. What is a possible consequence of this syndrome?
A. Hypercalcemia
B. Hypoalbuminemia
C. Hyponatremia
D. Metabolic alkalosis
B. Hypoalbuminemia
Which of the following is the MOST appropriate in the anesthetic management of a patient with an intracerebral arteriovenous malformation undergoing general anesthesia for embolization of the lesion?
A. Avoidance of all glucose containing solutions
B. Ensuring a slow emergence from anesthesia
C. Permissive hypertension during intubation
D. Use of a depolarizing muscle relaxant for paralysis
A. Avoidance of all glucose containing solutions
Which of the following is TRUE regarding intraoperative neuromonitoring (IONM) during aortic surgery?
A. Loss of cortical potentials from tibial nerve stimulation implies spinal cord ischemia during aortic repair
B. Several randomized controlled trials support the routine use of intraoperative neuromonitoring for aortic surgery
C. Somatosensory evoked potentials (SSEPs) have quicker responses than motor evoked potentials (MEPs)
D. Volatile anesthetics suppress motor evoked potentials (MEPs) to a lesser degree than somatosensory evoked potentials (SSEPs)
A. Loss of cortical potentials from tibial nerve stimulation implies spinal cord ischemia during aortic repair
Which of the following statements regarding spinal cord blood supply is CORRECT?
A. One posterior spinal artery supplies the posterior spinal cord
B. Radicular arteries supplement the anterior but not the posterior spinal cord blood supplies
C. The anterior spinal artery supplies the anterior two thirds of the spinal cord
D. The artery of Adamkiewicz most commonly originates in the T5-T8 region
C. The anterior spinal artery supplies the anterior two thirds of the spinal cord
A 36-year-old man with amyotrophic lateral sclerosis, hyperlipidemia, urinary retention, and chronic urinary tract infections presents for cystoscopy and suprapubic urinary catheter placement. He is wheelchair bound with progressive weakness, dysphagia, and dysphonia. He has had two incidents of occult aspiration pneumonia in the past two years. He has never seen a cardiologist and has no preoperative cardiac testing. Which of the following anesthetic plans would be the most reasonable for this patient?
A. Delaying the surgery for a cardiac catheterization
B. Modified rapid sequence induction with propofol and rocuronium
C. Rapid sequence induction with propofol and succinylcholine
D. Subarachnoid block with lidocaine
B. Modified rapid sequence induction with propofol and rocuronium
Which of the following MOST likely interferes with acetylcholine release?
A. Hypocalcemia
B. Myasthenia gravis
C. Nifedipine
D. Potassium channel blockers
A. Hypocalcemia
A 33-year-old woman has developed acute inflammatory demyelinating polyradiculopathy (Guillain-Barré syndrome) following an acute gastrointestinal illness. Due to the severity of her condition, the decision has been made to intubate the patient and provide mechanical ventilation for respiratory support. Which of the following is MOST TRUE regarding this patient’s care?
A. Muscle paralysis is typically maintained to facilitate mechanical intubation
B. Prior to intubation, this patient’s forced expiratory volume in one second will be decreased
C. The use of succinylcholine to facilitate intubation is recommended
D. Ventilator settings following intubation will demonstrate decreased lung compliance
B. Prior to intubation, this patient’s forced expiratory volume in one second will be decreased
A 45-year-old male post motor vehicle accident has a Glasgow Coma Scale score of 7, blood pressure of 85/60 mmHg, and a subdural hematoma seen on CT scan. What is the MOST accurate and useful method to assess his intracranial pressure?
A. Intraparenchymal catheter
B. Lumbar subarachnoid catheter
C. Optic nerve sheath diameter with ultrasound
D. Ventriculostomy catheter
D. Ventriculostomy catheter
A 39-year-old man with history of cervical spondylosis is diagnosed with anterior spinal artery syndrome after onset of symptoms. Which of the following is most likely intact?
A. Motor function
B. Temperature sensation
C. Pain sensation
D. Proprioception
D. Proprioception
Which of the following interventions is most likely to be effective for the prophylaxis of post-operative nausea and vomiting (PONV)?
A. Acupuncture
B. Isopropyl alcohol inhalation
C. Nicotine patch to non-smokers
D. Tetrahydrocannabinol
A. Acupuncture
Which of the following does NOT contribute to the termination of an action potential in a neuron?
A. Neuron membrane repolarization
B. Sodium channel inactivation
C. Calcium ion efflux
D. Potassium ion efflux
C. Calcium ion efflux
A 16-year-old girl is scheduled to undergo minimally invasive repair of pectus excavatum with the placement of two pectus bars. Analgesia is planned with the preoperative placement of bilateral paravertebral nerve catheters. Which of the following is the MOST reliable means of identifying vertebra prominens (C7) when determining the placement of the paravertebral catheters?
A. Palpation of the most cephalad stationary spinous process on neck flexion and extension
B. Palpation of the most prominent spinous process
C. The spinous process underlying the line connecting the roots of the bilateral scapular spines
D. The spinous process underlying the intercristal line
A. Palpation of the most cephalad stationary spinous process on neck flexion and extension
Which of the following statements regarding nitrous oxide and cerebral blood flow (CBF) is FALSE?
A. CBF is increased significantly when nitrous oxide is administered alone
B. CBF response to carbon dioxide is preserved with nitrous oxide use
C. IV anesthetics blunt the CBF changes seen with nitrous oxide
D. Substituting nitrous oxide for volatile anesthetic will not affect CBF as long as the MAC value is unchanged
D. Substituting nitrous oxide for volatile anesthetic will not affect CBF as long as the MAC value is unchanged
Which of the following statements regarding nitrous oxide and cerebral blood flow (CBF) is FALSE?
A. CBF is increased significantly when nitrous oxide is administered alone
B. CBF response to carbon dioxide is preserved with nitrous oxide use
C. IV anesthetics blunt the CBF changes seen with nitrous oxide
D. Substituting nitrous oxide for volatile anesthetic will not affect CBF as long as the MAC value is unchanged
D. Substituting nitrous oxide for volatile anesthetic will not affect CBF as long as the MAC value is unchanged
A 32-year-old woman with a history of myasthenia gravis presents for transsternal thymectomy. Which of the following preoperative risk factors MOST predicts the need for extended postoperative ventilation in this patient?
A. Dose of pyridostigmine greater than 750 mg daily
B. Duration of myasthenia gravis for more than 6 years
C. History of chronic respiratory disease other than myasthenia gravis
D. Preoperative vital capacity less than 2.9 liters
B. Duration of myasthenia gravis for more than 6 years
You are caring for an 18-year-old patient undergoing urgent exploratory laparotomy for small bowel obstruction secondary to adhesions. An airway cart is obtained prior to induction, which includes multiple airway modalities including jet ventilation, a fiberoptic scope, and a tracheostomy kit. The patient was given propofol and succinylcholine for induction. Following administration of induction medications, the patient develops severe trismus with no other muscle rigidity noted. Vital signs are BP 110/70 mmHg, HR 105 bpm, SpO2 100%, and temperature 37.1 degC. Of the following, which is the MOST appropriate?
A. Administer dantrolene immediately
B. Insert a nasal airway and mask ventilate until trismus resolves
C. Perform immediate tracheostomy
D. Perform nasal fiberoptic intubation with an apneic oxygenation technique
D. Perform nasal fiberoptic intubation with an apneic oxygenation technique
Which of the following is TRUE regarding congenital myasthenic syndromes (CMS)?
A. Inheritance is almost always autosomal dominant
B. Pathology is secondary to genetic mutations for proteins involved in neuromuscular transmission
C. Peri-operative plasmapheresis may be beneficial for crises
D. The most common defect is related to presynaptic acetylcholine release
B. Pathology is secondary to genetic mutations for proteins involved in neuromuscular transmission
With regard to myasthenia gravis and myasthenic syndrome, which of the following is correct?
A. Myasthenia gravis: weakness improves with repetition
Myasthenic syndrome: weakness worsens with repetition
B. Myasthenia gravis: circulating antibodies against voltage-gated calcium channels
Myasthenic syndrome: circulating antibodies against acetylcholine receptors
C. Myasthenia gravis: weakness most often involves bulbar muscles
Myasthenic syndrome: weakness most often involves the proximal extremities
D. Myasthenia gravis: More sensitive to succinylcholine
Myasthenic syndrome: Less sensitive to succinylcholine
C. Myasthenia gravis: weakness most often involves bulbar muscles
Myasthenic syndrome: weakness most often involves the proximal extremities
Which of the following changes will cause the GREATEST decrease in cerebral blood flow during otherwise normal physiologic conditions?
A. Decreasing PaO2 from 80 to 45 mm Hg
B. Decreasing mean arterial blood pressure from 100 to 70 mm Hg
C. Decreasing body temperature from 37 to 34 degrees Celsius
D. Increasing PaCO2 from 40 to 60 mm Hg
C. Decreasing body temperature from 37 to 34 degrees Celsius
Which of the following ions is MOST responsible for the maintenance of the resting neural membrane potential between -60 and -90 mV?
A. Calcium
B. Chloride
C. Potassium
D. Sodium
C. Potassium
A 43-year-old man with a history of ulcerative colitis just underwent an uncomplicated total proctocolectomy with ileostomy placement. Neuromuscular blockade was maintained throughout the case with a vecuronium infusion. Which of the following statements is MOST TRUE regarding the assessment of the recovery from neuromuscular blockade?
A. Tactile fade to train-of-four stimulation is superior to acceleromyography for detecting residual neuromuscular blockade
B. Presence of adequate unsupported tidal volumes precludes the need for further assessment of neuromuscular blockade
C. Train-of-four stimulation of the adductor pollicis more closely reflects blockade of the larynx when compared to the corrugator supercilii
D. Use of double-burst stimulation is more sensitive for the detection of fade when compared to standard train-of-four monitoring
D. Use of double-burst stimulation is more sensitive for the detection of fade when compared to standard train-of-four monitoring
Which of the following is the most correct regarding endovascular cerebral aneurysm repair compared to craniotomy and surgical clipping?
A. After open surgical repair, patients should remain intubated and after endovascular repair patients can be extubated at the end of the case
B. Avoiding coughing on emergence is primarily a concern with open repair
C. Hyperventilation should be avoided with endovascular repair, but not with open surgery
D. The complications associated with endovascular repair are less severe than those associated with open repair
C. Hyperventilation should be avoided with endovascular repair, but not with open surgery
Which of the following would be LEAST likely to result in an episode of autonomic hyperreflexia?
A. A patient with a C6 spinal cord lesion undergoing simple fecal disimpaction
B. A laboring patient with a prior T4 spinal cord injury
C. A patient with a T10 spinal cord lesion undergoing cystoscopy
D. Visceral stimulation below the spinal cord lesion in a patient with a T5 injury
C. A patient with a T10 spinal cord lesion undergoing cystoscopy