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Chapter 26 & 27
Pharmacology Exam 3
Question | Answer |
---|---|
_____ _____ stop nerve conduction by blocking sodium channels in the axon membrane | local anesthetics |
small, nonmyelinated neurons are blocked more _____ than large, myelinated neurons | rapidly |
what are the two classes of local anesthetics? | ester-type and amide-type |
_____ anesthetics occasionally cause allergic reactions and are inactivated by esterase in the blood | ester-type |
_____ is an example of an ester-type local anesthetic | procaine |
_____ anesthetics rarely cause allergic reactions and are inactivated by enzymes in the liver | amide-type |
the onset of anesthesia occurs most rapidly with anesthetics that are what? | small, lipid-soluble, and nonionized at physiologic pH |
termination of local anesthesia is determined in large part by what? | regional blood flow |
coadministration of epinephrine, a vasoconstrictor, will _____ anesthesia? | prolong |
local anesthetics can cause systemic toxicity if they are absorbed in sufficient doses. true or false? | true |
what are the principal concerns of local anesthesia causing systemic toxicity? | cardiac dysrhythmias and CNS effects (seizures, unconsciousness, coma) |
(1) using the smallest amount needed (2) avoiding application to large areas (3) avoiding application to broken our irritated skin (4) avoiding strenuous exercise and use of dressings or heating pads are all ways to reduce risk of what? | systemic toxicity from topical anesthetics |
_____ _____ produce unconsciousness and insensitivity to painful stimuli | general anesthetics |
_____ reduce sensitivity to pain but do not reduce consciousness | analgesics |
the term _____ _____ refers to the use of several drugs to ensure that induction of anesthesia is smooth and rapid and that analgesia and muscle relaxation are adequate | balanced anesthesia |
a low MAC indicates what? | high anesthetic potency |
_____ _____ work by enhancing transmission at inhibitory synapses and by inhibiting transmission at excitatory synapses | inhalation agents |
inhalation agents undergo minimal hepatic metabolism and are eliminated almost entirely by what? | expired air |
what are the principal adverse effects of general anesthetics> | depression of respiration and cardiac performance |
coadministration of _____ with general anesthetics increases the risk of malignant hyperthermia | succinylcholine |
opioids reduce the required dosage of a general anesthetic by doing what? | enhancing muscle relaxation |
_____ _____ differs from other general anesthetics in 2 important ways: (1) it has a very high MAC and therefore cannot be used alone to produce general anesthesia (2) it has high analgesic potency and therefore is frequently combined with other general | nitrous oxide |
what drug is a rapid-acting agent with an ultrashort duration of action? | propofol |
propofol is widely used along for what? | diagnostic procedures |
as a component of balanced anesthesia, propofol is combined with what? | an inhalation anesthetic |
an IV anesthetic that produces a state known as dissociative anesthesia | ketamine |
patients recovering from ketamine may experience adverse _____ reactions | psychologic |
local anesthesia effects _____ fibers first, then _____ fibers | small; large |
(1) autonomic activity (2) pain (3) other senses is the order in which anesthetics do what? | induce paralysis |
recovery from paralysis happens in what order? | motor, sensory, autonomic activity |
systemic effects from local anesthetics can be caused by what? | systemic blockade of epinephrine and NE |
the onset of local anesthesia depends on what? | molecular size, lipid solubility, and the degree of ionization |
the duration of action of local anesthetics is determined by what? | molecular size, lipid solubility, and the degree of ionization |
in what manner does blood flow affect the duration of action? | the higher the blood flow, the quick and shorter the duration of action |
vasoconstrictors are often given with local anesthetics to reduce blood flow to the area and prolong anesthesia. however, they have an additional benefit of what? | reducing the risk for toxicity by slowing absorption |
vasoconstrictors are metabolized by what organ? | liver |
what is one example of a vasoconstrictor that can be given with a local anesthetic? | epinephrine |
what are some adverse effects of local anesthetics related to their local blocking of sensations? | skin breakdown, self-injury because of the loss of sensation, and loss of skin integrity |
restlessness, anxiety, tremors, dizziness, blurred vision, and backache are all possible adverse effects on the CNS of what? | local anesthetics |
_____ is an adverse effect of local anesthetics that happen especially often with epidural or spinal anesthesia | headache |
seizures caused by local anesthesia can be managed by what drug? | thiopental |
peripheral vasodilation, myocardial depression, arrhythmias, blood pressure changes, fatal cardiac or respiratory arrest, heart block, bradycardia, and reduction in the force of ventricular contraction are all examples of what? | potential adverse effects of local anesthetics on the cardiovascular system |
procain, a local anesthetic, is primarily used for what? | dental procedures |
is procain an ester or amide anesthetic? | ester-type |
how is procain administered? | injection into the tissue |
what is the brand name for procain? | novocain |
all _____ have an i before the word caine | amides |
lidocaine is what type of local anesthetic? | amide-type |
which group of the local anesthetics produces the most allergic reactions? | amide-type |
what is the most widely used local anesthetic? | lidocaine |
lidocaine is also used for what? | cardiac dysrhythmias |
what pregnancy category is lidocaine in? | pregnancy b |
lidocaine is available alone and in different concentrations with what? | epinephrine |
- cream -ointment -jelly -solution -aerosol -patch are all the preparations in which what drug is available? | lidocaine |
lidocaine has a _____ onset | fast |
what was the first local anesthetic? | cocaine |
what surgeries is cocaine still used in today? | ear, nose, and throat |
_____ cannot be given with vasoconstrictors | cocaine |
generalized stimulation, euphoria, reduced fatigue, and increased social ability and alertness are the CNS effects of what? | cocaine |
heart muscle stimulation, vasoconstriction, tachycardia, potentially fatal dysrhythmias, and risk for hypertension are the possible cardiovascular effects of what? | cocaine |
when local anesthetics are applied topically, they are applied directly where? | dry, intact skin or mucous membranes |
the therapeutic uses of topical anesthetic include what? | relief of pain, itching, burning, and generalized soreness |
multiple small injections to produce a more limited or local anesthetic fields | infiltration |
local anesthetic of a specific peripheral nerve that involves relatively deep injections of the drug into locations adjacent to the major nerve trunk or ganglia that focuses on a relatively large body region | nerve block |
injection of parenteral anesthetic drugs into an area near the spinal cord that is generally used to block all peripheral nerves that branch out distally from the injection sight | spinal (subarachnoid) |
what drugs are usually given by spinal injection? | opioids and lidocaine |
what innervates the surgical site for several days during postop? | pumps |
a state of reduced neurologic function is called what? | anesthesia |
how do anesthetics reduce or eliminate pain? | by depressing nerve conduction in the CNS or in the PNS |
general anesthetics produce a complete loss of body reflexes, including what? | respiratory support |
loss of sensibility of pain | analgesia |
loss of pain and loss of all other sensations | anesthesia |
what are the 2 main groups of general anesthetics? | inhalation and IV |
inhalation anesthetics are what? | volatile liquids or gases |
inhalation anesthetics are very rapidly absorbed because they go through what? | pulmonary circulation |
what is the biggest drawback of inhalation anesthetics? | pungent odor |
__ anesthetics are used for the induction or to maintain the general anesthesia | IV |
what are some side effects of IV general anesthetics? | respiratory, cardiac, and blood pressure depression |
_____ _____ is a combination of drugs used to accomplish the desired effects of anesthesia that allows us to give the lowest dose of anesthesia necessary and decreases the cardiovascular risk and risk to any other organs | balance anesthesia |
why are short-acting barbiturates commonly combined with inhalation anesthetics? | to help with the induction of anesthesia |
why are neuromuscular agents commonly combined with inhalation anesthetics? | to aid in neuromuscular relaxation |
why are opioid or nitrous oxides commonly combined with inhalation anesthetics? | pain relief |
it is believed that inhalation anesthetics _____ activation of GABA receptors and increase sensitivity of GABA receptors | enhance |
MAC stands for what? | minimum alveolar concentration |
the concentration of anesthesia needed that will produce immobilization in approximately 50% of patients | MAC |
the _____ the concentration of anesthetic, the more rapid the upatke | greater |
distribution of anesthetics to the CNS and other tissues is determined by what? | regional blood flow |
inhalation anesthetics can cause what? | malignant hyperthermia and aspiration of gastric contents |
benzodiazepines are given as a preanesthetic addict to inhalation anesthesia for what purpose? | to reduce anxiety and create some amnesia for the patient |
opioids are given as a preanesthetic addict to inhalation anesthesia for what purpose? | reduction of pre and post operative pain |
clonidine, an alpha2-adrenergic agonist, is given as a preanesthetic addict to inhalation anesthesia for what purpose? | relieve high blood pressure and help with pain |
anticholinergic drugs are given as a preanesthetic addict to inhalation anesthesia for what purpose? | reduce the risk for bradycardia and prevent excessive secretion |
neuromuscular blocking agents reduce the amount of anesthesia need and prevent contraction of all skeletal muscles, including what? | the diaphragm and muscles of respiration |
postoperative mild pain is treated with what? | aspirin-like drugs |
an example of an antiemetic used postoperatively is what? | ondansetron |
postoperative severe pain is treated with what? | opioids |
muscarine antagonists are given postoperatively in order to treat what? | abdominal distention and urinary retention |
(1) halothane (2) isoflurane (3) enflurane (4) desflurance (5) sevoflurane are all examples of what? | inhalation anesthetics |
which inhalation anesthetic is no longer available in the US? | halothane |
_____ _____ is unstable at room temperature, releases gases that are inhaled but he patient, and act like a gas anesthetic | volatile liquid |
hypotension, respiratory depression, promotion of dysrhythmias, malignant hyperthermia, and hepatotoxicity are all adverse effects of what? | halothane |
respiratory depression as a result of anesthesia requires treatment with what? | oxygen-rich gas mixture |
promotion of dysrhythmias as a result of anesthesia can be treated cautiously with what? | epinephrine and catecholamines |
what is the most widely used inhalation anesthetic? | isoflurane |
what is isoflurane's onset of action? | 1-2 minutes |
recovery from the effects of isoflurane starts how long after administration? | approximately 15 minutes |
what inhalation anesthetic has a structure nearly identical to isoflurane? | desflurane |
which volatile anesthetic induces its action faster than any other anesthetic? | desflurane |
nitrous oxide has a very ____ anesthetic potency and very _____ analgesic potency | low; high |
nitrous oxide is ____ used as an anesthetic | NEVER |
there are no serious side effects to nitrous oxide. however, it can cause _____ and _____ | nausea; vomiting |
what is the onset of action for nitrous oxide? | 1-2 minutes with rapid recovery |
what drugs can be used as IV anesthetics? | short-acting barbiturates, Benzos, propofol, and ketamine |
short-acting barbiturates can be given intravenously to do what? | induce rapid anesthesia |
what is the only legal drug remaining in the short-acting barbiturates class? | methohexital |
methohexital produces unconsciousness within _____ after administration | 10-20 seconds |
methohexital lacks _____ properties | analgesic |
methohexital is contraindicated for patients with what? | silicone implants |
what are some adverse effects of methohexital directly related to CNS depression? | bradycardia, hypotension, decreased GI activity, nausea, and vomiting |
methohexital can cause decreased effectiveness with what? | oral anticoagulants, beta blockers, and normal contraceptives |
what are the 2 benzodiazepines commonly administered IV as anesthetics? | diazepam and midazolam |
IV diazepam can produce unconsciousness within _____ | 1 minute |
IV midazolam can produce unconsciousness within _____ | 80 seconds |
when _____ is given IV for anesthesia, it causes very little muscle relaxation | diazepam |
when _____ is given IV for anesthesia, it can cause dangerous cardiorespiratory effects | midazolam |
mechanically ventilated patients are frequently on what medication because it is quickly removed from the system once administration is stopped? | propofol |
propofol can cause what? | severe hypotension |
propofol is a controlled substance is a controlled substance. true or false? | false |
ketamine can cause _____ _____, sedation, immobility, analgesia, and amnesia | dissociative anesthesia |
adverse psychologic reactions to ketamine include what? | hallucinations, disturbing dreams, and delirium |
a ____ _____ should be provided for patients recovering from anesthesia by ketamine because of the psychologic effects it can cause | soothing environment |