Anesthetics Flashcards
Pt receiving lidocaine for local anesthesia develops cyanosis, headache, tachycardia, shortness of breath, lightheadedness, and fatigue. Diagnosis?
Methemoglobinemia
Optimal distance above carina for an endotracheal tube
2 cm above carina
Relate lipid solubility, speed of induction, and potency for an inhalational agent with a low MAC
Low MAC means that agent is more lipid-soluble and more potent, but slower speed of induction
What inhalational agent has the fastest speed of induction, high MAC, and low potency?
Nitrous oxide (NO2)
Contraindications to use of nitrous oxide
Middle ear occlusion
Pneumothorax
SBO
Any other instance where there is air-filled body pocket
Which inhalational agent can cause eosinophilia, fever, increased LFTs, and jaundice, and is associated with the highest degree of cardiac depression and arrhythmias?
Halothane
Pleasant smelling and ideal for induction in children
Sevoflurane
What induction agent should not be used in pts with egg allergy?
Propofol
Induction agent contraindicated in head injury
Ketamine
Which induction agent can cause adrenocortical suppression with continuous infusion?
Etomidate
First muscle to be paralyzed after administration of paralytic
Face and neck muscles
Last muscle to be paralyzed after administration of paralytic
Diaphragm
Triggering agents for malignant hyperthermia
Volatile anesthetics (halothane, enflurane, isoflurane, sevoflurane, desflurane) and depolarizing paralytic succinylcholine
Mechanism leading to malignant hyperthermia
Mutation of ryanodine receptors on SR resulting in drastic increase in intracellular calcium levels inducing an uncontrolled increase in skeletal muscle oxidative metabolism
First sign seen with malignant hyperthermia
Increase in end-tidal CO2
[other signs: acidosis, fever, hyperkalemia, rigidity, tachycardia]
Use of succinylcholine should be avoided in which pts?
Extensive burns, crush injuries/extensive trauma, eye trauma or glaucoma, neuro disorders/injury, spinal cord injury, acute renal failure with increased potassium
Maximum dose of lidocaine without epinephrine
5 mg/kg
(Remember 1% of drug = 10 mg/mL)
[max dose of bupivacaine is 3 mg/kg]
Maximum dose of lidocaine with epinephrine
7 mg/kg
Earliest symptoms of lidocaine toxicity
Perioral numbness or tingling of the tongue
May progress to lightheadedness or visual disturbance, CV symptoms such as arrhythmias and arrest
In patients on MAOIs, the concurrent use of narcotics can cause _____ _____
Hyperpyrexic coma
Histamine release is characteristic of what narcotic?
Morphine
Which benzodiazepine is contraindicated in pregnancy because it crosses placenta?
Versed (midazolam)
What is the best determinant of esophageal vs. tracheal intubation?
End-tidal CO2
Risk factors for post-op MI
Age >70 CHF DM Previous MI Unstable angina
What is the risk in administering a depolarizing anesthetic agent such as succinylcholine in quadriplegics, paraplegics, or after burns and severe trauma?
Life-threatening hyperkalemia from release of intracellular potassium
Effects of inhaled anesthetics include ______ cardiac output, respiratory ______, and post-op atelectasis
Decreased; depression
Propofol 10 mg/mL dosage for general anesthesia induction
ASA-I, II — 2 to 2.5 mg/kg IV; Administer in approx. 40 mg increments every 10 seconds until onset of anesthesia
ASA-III, IV — 1-1.5 mg/kg IV; Administer in approx. 20 mg increments every 10 seconds until onset of anesthesia
Children age 3-16 — 2.5-3.5 mg/kg IV as single dose over 20-30 seconds