Skip to Main Content

Anesthesia

Patty T. Liu

TEST TAKING TIPS

Test Taking Tips

Remember to review lidocaine toxicity, especially the signs and symptoms and the maximum dose that can be given.
Know the advantages and disadvantages of using an epidural versus a PCA for postoperative pain control.

What is the optimal distance above the carina for an endotracheal tube (ETT)?

2 cm above the carina

What are the steps of rapid sequence induction?

Oxygenation and short-acting induction agent → muscle relaxant → cricoid pressure → intubation → inhalational anesthetic

What is the most commonly used technique for induction of general anesthesia in children?

Inhalational

What are the steps that both the surgeon and anesthesiologist should take during an airway fire?

Stop all gas and oxygen flow → extinguish fire with water/saline → remove ET tube and any foreign body in airway → perform mask ventilation until patient is reintubated → perform bronchoscopy to assess extent of airway damage.

What factors affect the accuracy of pulse oximetry?

Decreased reading—intense environmental lighting, motion, methylene blue dye, hypothermia, low cardiac output, hypotension, peripheral edema, nail polish
Increased reading—bilirubin, carbon monoxide

Define minimum alveolar concentration (MAC):

The smallest concentration of gas at which 50% of patients will not move to painful stimuli such as incision

Relate lipid solubility, speed of induction, and potency for an inhalational agent with a low MAC:

Low MAC means that the agent is more lipid-soluble and more potent but slower speed of induction

What inhalational agent has the fastest speed of induction, high minimal alveolar concentration, and low potency?

Nitrous oxide (NO₂)

Name contraindications to the use of nitrous oxide:

Middle ear occlusion, pneumothorax, small bowel obstruction, and any other instance where there is an air-filled body pocket

Which inhalational agent can cause eosinophilia, fever, increased liver function tests, and jaundice and is associated with the highest degree of cardiac depression and arrhythmias?

Halothane

Which inhalational agent has a pleasant smell and is ideal for mask induction in children?

Sevoflurane

What induction agent should not be used in patients with an egg allergy?

Propofol

What induction agent is contraindicated in head injury?

Ketamine

Which induction agent can cause adrenocortical suppression with continuous infusion?

Etomidate

First muscle to be paralyzed after administration of a paralytic? Last muscle?

Face and neck muscles
Diaphragm

First muscle to recover after administration of a paralytic? Last muscle?

Diaphragm
Face and neck muscles

Triggering agents for malignant hyperthermia:

Volatile anesthetics (halothane, enflurane, isoflurane, sevoflurane, desflurane) and depolarizing paralytic succinylcholine

What is the mechanism leading to malignant hyperthermia?

Mutation of the ryanodine receptors located on the sarcoplasmic reticulum resulting in a drastic increase in intracellular calcium levels inducing an uncontrolled increase in skeletal muscle oxidative metabolism

First sign seen with malignant hyperthermia? Other signs?

Increase in end-tidal CO₂
Acidosis, fever, hyperkalemia, rigidity, tachycardia

Treatment for malignant hyperthermia:

First stop offending agent, cooling blankets, dantrolene (10 mg/kg IV), glucose, HCO₃, IV fluids, supportive care

Name the only depolarizing paralytic

Succinylcholine

Use of succinylcholine should be avoided in which patients?

Patients with extensive burns, crush injuries/extensive trauma, eye trauma or glaucoma (raises intraocular pressure), neurologic disorders/injury, spinal cord injury, acute renal failure with increased potassium

How long does succinylcholine last? Metabolized by? Antidote?

<6 minutes, hydrolyzed by plasma cholinesterase (pseudocholinesterase), time

How is cisatracurium metabolized?

Hofmann elimination

How is mivacurium metabolized?

Hydrolyzed by plasma cholinesterase

What is the most common side effect of pancuronium?

Tachycardia (vagolytic effect)

What can be used to reverse nondepolarizing paralytics?

Acetylcholinesterase inhibitors (neostigmine, edrophonium, pyridostigmine)

Mechanism of action of local anesthetics:

Blocks transmission of neural impulses by stabilizing Na channels, thus preventing propagation of action potential

Where is lidocaine with epinephrine contraindicated?

Fingers, penis, nose, pinna of ear, and toes (vasoconstriction can lead to ischemia/necrosis)

Maximum dose of lidocaine without epinephrine? Lidocaine with epinephrine (1:100,000)?

5 mg/kg (remember 1% of drug = 10 mg/mL)
7 mg/kg

Maximum dose of bupivacaine:

3 mg/kg

Earliest symptom of lidocaine toxicity:

Perioral numbness or tingling of the tongue are early symptoms. This may progress to lightheadedness and visual disturbances. CNS-related symptoms are more common and occur before cardiovascular-related symptoms such as cardiac arrhythmias and arrest.

Severe signs seen with a large overdose of lidocaine:

Tonic-clonic seizures, unconsciousness, and eventually coma (cardiovascular toxicity less common)

Duration of lidocaine without epinephrine? Lidocaine with epinephrine?

30 to 60 minutes
Up to 4 hours

Type of local anesthetic that is more likely to cause an allergic reaction secondary to a p-aminobenzoic acid analogue:

Ester-type anesthetics (cocaine, procaine, tetracaine)

Most feared side effect of bupivacaine (Marcaine) after intravascular injection:

Fatal refractory dysrhythmia

In patients on monoamine oxidase inhibitors, the concurrent use of narcotics can cause:

Hyperpyrexic coma

Histamine release is characteristic of this narcotic:

Morphine

Name of the metabolite of demerol that can cause seizures:

Normeperidine

Overdose of narcotic can be treated with this drug:

Narcan

Which benzodiazepine (BZ) is contraindicated in pregnancy because it crosses the placenta?

Versed (midazolam)

Competitive inhibitor of BZs that can be given to treat an overdose:

Flumazenil

True or false: Flumazenil can also reverse the CNS effects of other GABAergic-acting drugs such as barbiturates and ethanol?

False, only works with BZs

Contraindications to use of flumazenil:

Patients with serious signs of tricyclic antidepressant overdose and when BZs are used for life-threatening conditions (status epilepticus, increased intracranial pressure)

Initial treatment for a postdural puncture headache:

Conservative measures with analgesics, bed rest, and fluids

Treatment to relieve severe symptoms associated with postdural puncture headache persisting after 24 hours after ineffective conservative measures:

Epidural blood patch

Name some side effects of epidural anesthesia:

Decreased motor function, orthostatic hypotension, urinary retention

Treatment for hypotension from epidural anesthesia:

Turn down epidural dose, IV fluids, and phenylephrine

Major advantage of epidural anesthesia:

Analgesia without decreased cough reflex

Morphine in an epidural can contribute to this untoward effect:

Respiratory depression

Lidocaine in an epidural can contribute to these untoward effects:

Bradycardia and hypotension

When should the foley be taken out with an epidural catheter?

Several hours after the epidural catheter is removed (epidural can cause urinary retention)

What is the best determinant of esophageal versus tracheal intubation?

End-tidal CO₂

Most common postanesthesia care unit complication from anesthesia:

Nausea and vomiting

List the greatest risk factors for postop myocardial infarction (MI):

Age >70, congective heart failure, diabetes mellitus (DM), previous MI, and unstable angina

Most common cause of sudden transient rise in end-tidal CO₂ in intubated patient? Other causes of rise in end-tidal CO₂?

Alveolar hypoventilation (increase tidal volume or respiratory rate to correct)
Malignant hyperthermia, release of tourniquet, pneumothorax, mucus plug, faulty equipment

Causes for sudden decrease in end-tidal CO₂ in the intubated patient?

Disconnection from ventilator, kinking of ETT, pulmonary embolism (PE), significant hypotension, CO₂ embolus

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.