Exam 2 Start: Week 4 - Surgical Meds Flashcards
Prototype Drugs for Medicaitons r/t to Surgery
Nitrous Oxide
Isoflurane (Forane)
Propofol (Diprivan)
Fentanyl (Sublimaze)
Midazolam (Versed)
Procaine and Lidocaine
Rocuronium (Zemuron)
Succinylcholine (Anectine)
Balanced Anesthesia
Use of various combinations of medications for the best results to provide sleep, analgesia, elimination of certian reflexes and good muscular
No one drug can do all these things alone
What sort of effects do we want from anesthesia
Analgesia
Decreased LOC (Coma) / Amensia
Decrease Anxiety
Decrease Muscle Activity
Decrease Secretions / N/V
Get into system quickly and leave the system quickly
no one magic drugs all of these at the same time
What are the 3 types of Anesthetic Drugs and the 1 Adjunct Category
- Inhalation Anesthetics
- IV Anesthetics
- Local Anesthetics
1 Adjunct: Skeletal Muscle Relaxant
Inhalation Anesthetics
Anesthesia Drugs administered through the respiratory tract - dosage is dependent of many things, but can be controlled by anesthetist – both inhalation and exhalation
2 Subtypes of Inhalation Anesthetics
- Gaseous
2. Vaporous
Classification of Nitrous Oxide
“Laughing Gas”
Gaseous (Inhalation) General Anesthetic
Gaseous General Anesthetic
Type of Inhalation Anesthetics
ex: NO
Causes ANALGESIA, narcosis, and amnesia by depressing the CNS via GABA - however does not depress the CNS well like volatile anesthetics
GABA receptor agonist, opioid agonist
How does gaserous general anesthetic cause its depression of CNS effect
it is a GABA receptor agonist / opioid agonist
Narcosis
effects that narcotics / opioids cause
ex; Sedation, pain relief, sleepiness, less anxiety, etc.
The big benefit of nitrous oxide is what
Analgesia
Why is nitrous oxide enver used for long procedures?
It does not last lone, but it does have a HIGHLY ANALGESIC EFFECT
Anesthesia is more than analgesia, it effects…
CNS, sensation, movement, etc
there are differing levels of anesthesia
What is Nitrous Oxides potentcy
very potent - small amounts give the effect wanted
ADRs of Gaseous General Anesthesia (Nitrous Oxide)
Suprisingly free of major toxicities when given WITH OXYGEN
Does compress normal tissue oxygenation if balance between NO and O2 is not adequate
Toxic Suppression of CNS can occur
Post op N/V can occur (more so than other drugs)
Nitrous Oxide does not…
cause complete loss of consciousness
Gaseous General Anesthesia (Nitrous Oxides) greatest use?
An induction agent - gets a person to the state where you can do the procedure / induce the effects (analgesia in this case)
Gaseous General Anesthesia (nitrous oxide) must be given with what?
- MUST be given in combination with oxygen (at least 30% oxygen)
- Must be given with other agents except in very short procedures
Important Points about Nitrous Oxide (General Gaseous Anesthesia)
Strong Analgesic, Poor Anesthetic (Depressing CNS)
Some N/V
Better to give with O2 in good balance
General Volatile Anesthesia
Type of Inhalation Anesthetics
Not a gas, it is a liquid that is more soluble in blood, ICF, and fat tissue than gas
Not explosive
What does the high solubility of General Volatile Anesthesia mean
There is slower onset in induction and slower recovery
High solubility will allow tissues and blood concentrations to build up unless carefully titrated
Classification of Isoflurane (Forane)
Inhaled General Volatile Anesthetic
What is the action of volatile asthetic
Progressive depression of CNS (exact action unknown); GABA (inhibition) and glutamate receptor agonist
Suffix: “-ane”
General Volatile Anesthetics
Which inhalation classification is better for longer procedures
General Volatile Anesthetics
What is the important thing that general volatile anesthetics does in comparison to gaseous general anesthetics
Volatile Anesthetics will depress the CNS, but its not as good for Analgesia like gaseous general anesthesia
Why can Isoflurane be used in longer procedures
it can be titrated up or down depending on if it is going longer or if it is done quickly
What are some other effects (not ADR) that can occur from isoflurane (volatile general anesthesia)
Hypotension (from vasodilation, not cardiac output effects)
Respiration - less efficient exchange of gas - rapid and shallow respirations; respiratory depression
Muscle - some relaxation by central depression
Liver - depressed function
Stronger CNS depression leads to this stuff
Why is the metabolism of isoflurane so important to know about?
It is minimal and since it crosses the blood brain barrier it has the intense CNS depressive effects
What is the typical method of excretion for inhaled anesthetics
respiratory (exhaled breaths)
ADR of Volatile General Anesthesia
- Hypotension (from vasodilation)
- Significant respiratory depression
- can trigger malignant hyperthermia - especially in conjunction with succinylcholine
How does volatile general anesthesia (isoflurane) simplify tracheal intubation
relaxes the tracheal area and depresses the reflexes
If isoflurane (volatile general anesthesia) is given alone…
it is NOT a potent analgesic
Has some mild skeletal muscle relaxant effects (but IS uterine muscle relaxant)
So if you need an agent for quick induction and one for muscle relaxant - if used alone, however, you could see the patient going through the stages of anesthesia because of the slow onset
Patients may do what following coming out of volatile general anesthesia
they may shiver
Other Volatile General Anesthesia drugs (other than isoflurane) that are related
desflurane (Suprane)
sevoflurane (Ultane)
Intravenous Anesthetics
IV drugs
inhalation can be uncomfortable or claustrophobic so this may be used
Types of IV Anesthetics
Hypnotics
Narcotics
Neuroleptics
Benzodiazepine
Example Drug for Hypnotics
propofol (Diprivan)
Example Drug for Narcotics
fentanyl (Sublimaze)
Example Drug for Neuroleptics
like Ketamine
Example Drug for Benzodiazepine
midazolam (versed)
Advantages of IV Anesthetics
rapid pleasant induction
absence of explosive hazards
low incidence of postop N/V (but some still quite sensitive)
Disadvantages of IV Anesthetics
laryngospasm and bronchospasm (may need intubation)
hypotension
resp. depression
Uses for IV Anesthetics
induce and maintain general surgical anesthesia
basal anesthesia (low start and add on top of it
usually use short acting and ultra short acting barbiturates (sedating meds)
Narcotic use
What is the major difference between barbiturates and gaseous agents is ___
safety
Why is safety so different between barbiturates and IV meds compared to gaseous agents
inhalation - anesthetist controls minute by minute administration and removal
IV - once administered, course of events must continue until out of system
Another term for Barbiturates
Hypnotics
Classification of Barbiturates/Hypnotics
IV general anesthetic, ultra short acting
propofol (Diprivan)
IV Anesthesia
like IV isoflurane
can use in short procedures like a colonscopy, ultra short acting
excites release of GABA (inhibitory NT) - promotes the release of GABA . Has short duration of anesthesia action
What is important to know about the pharmacokinetics/distribution of propofol
onset = 60 seconds; length of action - 3-5 minutes
have to shift to something inhaled or a longer drug after this not just keep giving it
ADRs of propofol
resp depression
hypotension from vasodilation
risk of bacterial infection (in lipid based emulsion)
propofol infusion syndrome (rare)
injection site pain
One bonus benefit of propofol
antiemetic properties - helps in anti vomiting
What is induction like for propofol
smooth, easy, and pleasant for the patient
propofol is not recommended for patients…
with severe heart disease or respiratory difficulties
propofol is NOT…
a controlled substance
Milk of Amnesia
another name for propofol as it is a milky white solution
propofol and michael jackson
physician prescribed this hypnotic as a sleep aid and mixed with other meds it was acting in its CNS depressant capacities and killed him
2 Other Common IV Hypnotic Drugs
etomidate (Amidate) - for induction of those with heart issues and cannot handle the cardiac effects
fentanyl/droperidol combination (Innovar) - an opioid and neuroleptic combo used for neurolept analgesia
Narcotics/Opioids
IV Anesthetics
Used as anesthetic as well as preoperatively and for analgesia
mostly known for analgesia but does provide anesthesia and sedation
Prototype drug for Narcotics/Opioids
fentanyl (Sublimaze)
fentanyl (Sublimaze)
a common street drug mixture, and why many overdose
It is like super charged morphine - 100x more powerful and measured in mcg rather than morphine’s mg
fentanyl is super __
potent
fentanyl is an opioid ___
agonist (binds to mu receptors and causes opioid activity - analgesia, sedation, etc)
ADR of fentanyl (Narcotics/Opioids)
euphoria
miosis
N/V
pruritis (may not even realize it)
constipation
hypotension
respiratory depression
bradycardia
BLACK BOX WARNING - Significant abuse potential
Miosis
pupil constriction/contraction - some degree of this occurs whether you take an opioid d/t addiction or prescribed
What schedule is fentanyl
II
What is important to know about rapid IV injection of fentanyl and other opioids/narcotics
large doses or rapid IV injection may cause muscle rigidity and apnea - observe closely!
(if it says push over certain time than push over that time)
How often should topical patches (duragesic - fentanyl /narcotic-opioid like) be changed
every 72 hours for pain control (but not surgical pain)
What pain is a topical opioid/narcotic patch for
chronic pain or cancer - not acute pain like in surgical
It is important to do what with topical opioid/narcotic patches
dispose carefully - people can get the drugs off the patches to use
Other than IV and Topical, what are other routes of narcotics/opioid administration
- lozenge on a stick (actiq) - not a lollipop, but can be used to give kids to get an IV in with order
- buccal tablets (Fentora) - between gums and cheeks - maybe for cancer pain or issues swallowing
Neuroleptics
Group of drugs that are called “Dissociative drugs” because they give a sort of out of body experience, no pain and you are detached from the environment.
If it is a painful procedure you may not even associate the pain or procedure with yourself and it leaves you unbothered
Is there loss of consciousness with neuroleptics
no - you appear awake but do not connect things to yourself
What types of procedures are neuroleptic ideal for
something that is uncomfortable BUT does not take long
What often needs to be given with a neuroleptic
nitrous oxide or an opioid
What is an important Neuroleptic Like Drug
ketamine (Ketalar)
ketamine (Ketalar)
“Dissociative anesthetic”
used to induce a trance like effect with analgesia, quietude and detachment from the environment
What is a unique new use for ketamine
it can be used in very resistent and persistent depression as the intense dissociative effect seems to fight major depression
What is a major issue with misuse of ketamine
it is used as a date rape drug
Neuroleptanesthesia
Effect produced by administering a neuroleptic agent, narcotic analgesic, and sometimes nitrous oxide with oxygen
Benzodiazepine
IV anesthetic drug class
ex: midazolam (Versed)
neuroleptic and skeletal muscle relaxant effect
What is the important Benzodiazepine IV Anesthetic to know
midazolam (Versed)
What is important to know about the half life of midazolam (Versed)
Its half life is 2.5 hours meaning it takes 10 hours for 4 half lifes and to fully wear off
ADRs of midazolam (Versed)
RESPIRATORY DEPRESSION (EVEN ARREST) - do not give too quickly! (1-3 m push)
Decreased alertness and amensia (can last rest of day)
Hypotension
Hiccups
Laryngospasm
Loss of Dexterity
Muscle Tremors, Tachycardia, SOB
What is the amnesia like when taking midazolam
anterograde - meaning there is loss of memory about the proecdure and after until it wears off
May not remember what was said to them or even discharge instructions
Does allow decreased anxiety though
Examples of other Benzodiazepines
diazepam (Valium) and lorazepam (Ativan)
4 Types of IV Anesthetics
Hypnotics
Narcotics/Opioids
Ketamine
Benzodiazepines
Local Anesthetics
anesthesia drugs that vary in duration but change sensation transmission
All local anesthetics end in what suffix
-caine or -cain
What are the important prototype drugs for local anesthetics to know
- Short duration mepivacaine (Carbocaine)
- lidocaine (Xylocaine)
- Long duration Bupivacaine (Marcaine)
How does local anesthetics (what is the action) cause their effects
they stabilize or elevate threshold of excitation of nerve cell membrane preventing depolarization
so, NO SENSATION TRANSMISSION OCCURS BY ELEVATING THE THRESHOLD - cannot fire nerve impulses
What is important to know about the metabolism and excretion of local anesthetics
they will basically just stay in their location of absorption until removed/deleted
ADRs of Local Anesthetics
Overdosage or systemic absorption gives general body effects and excites (excitement, convulsion) or depresses the CNS (bradycardia, hypotension, cardiac arrest) - we want it staying local
NV, pallor, apprehension
What is important to know about the sensation loss with local anesthetics
loss of all sensation occurs but pain fibers are AFFECTED FIRST - can still feel pressure though
If local anesthetics become systemic…
they can cause serious reactions (especially heart and brain)
Why are local anesthetics often given with vasoconstrictors
something like EP is given to constrict blood vessels in the area in order to keep the anesthetic in that tissue so it does not go systemic
What sort of effect do we want with local anesthetics
numbing, but maintain awareness but lose pain (analgesia)
Skeletal Muscle Relaxants
Adjunct Anesthetics
Drug allows binding to ACh receptors to prevent further firing and relax muscles
2 Important Prototype Drugs for Skeletal Muscle Relaxants
rocuronium (Zemuron)
succinylcholine (Anectine)
rocuronium (Zemuron)
NON DEPOLARIZING AGENT - Skeletal Muscle Relaxant
A ACh competitive drug that will cause neuromuscular blocking to cause “paralytic” effects
Does so by taking the space on the receptor ACh would attempt to take (Competitive Antagonist)
succinylcholine (Anectine)
DEPOLARIZING NEUROMUSCULAR BLOCKING AGENT - Skeletal Muscle Relaxant
Also resembles ACh so it fits into thre receptors and causes depolarization like ACh would but its more twitchy and seizure like - but then it sits on the receptor and does not allow repolarization (reset) –> more prolonged depolarization occurs and it is slowly inactivated –> leads to flaccid muscles that cannot move (just like a non depolarizing agent)
What is important to keep in mind about the distribution and pharmacokinetics of recuronium (Zemuron)
- It works 20-40 minutes only so its good for only short procedures like intubation
- Only effects muscles so they can be conscious and terrified
Never use rocuronium unless…
it is given with a sedative as well to prevent trapping them in their body since it does not hinder pain perception or consciousness
Skeletal Muscle Relaxants should always be given with what
a sedative
ADRs of rocuronium (Zemuron)
Tachycardia, Muscle Weakness, Salivation, HTN - many from stress and awareness
Why can’t recuronium cross membranes
it is positively charged/ionized so it cannot cross membranes, BBB, or placenta
What can reverse the effect of recuronium and other non depolarizing agents
Anticholinesterases like neostigmine that allow ACh accumulation
Both recuronium and succinylcholine do what
thesame effect (flaccid muscles) but in different ways
ADRs of succinylcholine
Muscle weakness
Bronchospasm
Apnea
Bradycardia
Hypotension
Arrhythmias
Increased Salivation
Postop Muscle Pain
Hyperthemia!!!
Despite ADRs, succinylcholine…
has low level toxicity
Why is post op muscle pain unique to succinylcholine
because it causes initial seizure or twitching activity that is very intense and causes pain in the muscles similar to that of a post workout
Which person has an increased risk for adverse effects with isoflurane (Forane)?
A. A 70 yo man with COPD
B. 66 yo woman with hypothyroidism
C. 80 yo woman with Parkinsons disease
D. A 16 yo girl with anorexia nervosa
A. a 70 yo man with COPD
Reason: Do I want to use an anesthetic that is depressing the respiratory system on this guy
A local anesthetic like lidocaine is NOT useful during:
A. Suturing of a Deep Laceration
B. Regional Blocks
C. General Anesthesia
D. Opthalmic Anesthesia
C: General Anesthesia
We do not want local anesthetics going systemic
