A/S - preanesthetics
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- Preanesthestics
- Preanesthetics
- Why are preanesthetics used?
- calm/sedate (smooth induction & recovery), reduce/eliminate adverse effects of general anesthetics, dec amt of general anesthetic required, decrease pain during & after sugery
- What are anticholinergics used for?
- decrease parasypathetic responses produced by anesthetic drugs
- What is the autonomic nervous system?
- Part of nervous system that controls involuntary bodily functions
- What are the two division of the autonomic nervous system?
- sympathetic and parasympathetic
- Define synapse
- space between nerve ending and receptor
- Define receptor
- site stimulated to respond when it recs neurotransmitter from nerve ending
- Define neurotransmitter
- chemical that is released from nerve ending & travels across synapse, stimulating receptor
- Define parasympathetic nervous system
- stimulation produces response for "all OK - relax" situations
- Define sympathetic nervous system
- stimulation produces responses for "fight or flight" situations
- What is the neurotransmitter that stimulates parasympathetic responses?
- Acetylcholine
- What is the neurotransmitter that stimulates sympathetic responses?
- Norepineprhine
- What are some parasympathetic responses?
- increased saliva & tear production, HR slows, pupils contract, blood pressure dec, bronchi constrict, incr GI motility & secretions
- What are some sympathetic responses?
- inc saliva & tear production, pupils dilate, inc HR, inc blood pressure, bronchi dilate, dec GI motility & secretions
- What does suffix ergic mean?
- does the work of, stimulates
- What does the suffix mimetic mean?
- mimics, has similar effect
- What does the suffix lytic mean?
- prevents, tears down the effects of
- What are anticholineric drugs used for?
- prevent hypersalivation, prevent bradycardia
- What are two examples of anticholinergics?
- Atropine and Glycopyrrolate
- Atropine and Glycopyrrolate are what kind of drugs
- anticholinergics
- Do anticholinergics have sedative effects?
- Not at therapeutic doses
- Atropine is derived from what deadly plant?
- Nightshade
- Is Atropine expensive?
- No, cheap
- What is the onset of Atropine SC? IM?
- SC - 20 min, IM - 10-15 min
- What is the duration of Atropine?
- 60 min after SC admin
- What are some precautions w/ Atropine
- Markedly reduces tear secretion (use artificial tears), avoid in pts w/ pre-ex rapid HR, produces thick mucous airway secretions, reduces GI activity, crosses placental barrier
- What are some signs of Atropine overdose?
- tachycardia, peripheral vasodilation, dry MM, thirst, hyperthermia, excitment, dilated pupils
- Glycopyrrolate has effects similar to ___ but costs __, has ___ duration, milder effects, and does not cross the placental barrier
- similar to Atropine but costs more, has longer duration (2-3 hrs), milder effects, and does not cross placental barrier
- Why are sedatives/tranquilizers used?
- calming effect, smooth induction & recovery, dec amt of general anesthetic reqd, prev excitatory of some anesthetics in some species
- Define sedative
- drug that causes reduced mental activity and sleepiness
- Define tranquilizer
- drug that reduces anxiety but does not necessarily decrease awareness & wakefulness
- What effects do phenothiazines have?
- sedation, antiemetic, antiarrhythmic, antihistamine, peripheral vasodilation, personality effects, penile prolapse, LACK OF ANALGESIA
- What is an example of a phenothiazine drug?
- Acepromazine
- Acepromazine is what kind of drug?
- phenothiazine
- Is Ace a controlled drug?
- No
- How long is the sedation provided by Acepromazine given IM?
- 2-8 hours
- What are some benefits of Acepromazine?
- not controlled, long sedation effect, antiemetic, antiarrhythmic
- Do phenothiazines (Acepromazine) provide analgesia?
- NO!!
- What are some precautions w/ Acepromazine?
- no analgesia, prolapse of third eyelid, vasodilation(avoid in hypotensive pts), lower seizure threshold
- What is the onset of Acepromazine given IM?
- 15 mins
- How can Ace be given?
- IM, SC, Oral, IV - with caution
- Acepromazine, Diazepam, Midazolam, Zolazepam, Xylazine, and Medetomidine are all what?
- sedatives/tranquilizers
- Diazepam, Midazolam, and Zolazepam are what kind of drug?
- Benzodiazepines
- What are the advantages of Benzodiazepines?
- antianxiety/calming effect, excellent muscle relaxation, anticonvulsant, minimal cardiac and respiratory depression
- Name three Benzodiazepines
- Diazepam, Midazolam, Zolazepam
- Are Benzodiazepines controlled?
- YES!
- What is a precaution of Benzodiazepines?
- may cause excitement when used alone
- What is the most commonly used preanesthetic sedative in veterinary medicine?
- Acepromazine
- What is the "big feature" of Diazepam?
- prevents seizures
- Diazepam is ___ sensitive
- light
- Diazepam is painful if given IM so it is usually given __ or ___
- IV or orally
- The only anesthetic agent that is physically compatible w/ Diazepam is ___
- Ketamine
- When drawing up Diazepam and Ketamine in the same syringe ___ is drawn up first. Why?
- Diazepam - do not want to get Ketamine into anything!
- Midazolam is expensive but is watersoluable so it can be administered ___.
- IM
- Zolazepam is most commonly seen as part of Telazol® - what is the other component?
- tiletamine
- Alpha 2 Agonists are also called what?
- Thiazine derivatives
- Thiazine derivatives are also called what?
- Alpha 2 Agonists
- What are 2 examples of Alpha 2 Agonists?
- Xylazine & Medetomidine
- Xylazine and Medetomidine are examples of what kind of drug?
- Alpha 2 Agonists/thiazine derivatives
- What are some advantages of Alpha 2 Agonists?
- Potent sedation, good muscle relaxation, effective analgesia, reversible, and not controlled
- Are Alpha 2 Agonists (xylazine & medetomidine) controlled?
- No
- Why are Alpha 2 Agonists only used in young, healthy patients?
- Can have potent cardiovasular effects
- Why is Atropine used w/ Alpha 2 Agonists?
- prevent bradycardia
- What are some other precautions of Alpha 2 Agonists (Xylazine & Medetomidine)?
- can be absorbed through skin and MM, analgesia wears off before sedation, emesis in 50% of dogs and 90% of cats, poss bloat - avoid in GDV risk pt
- What kind of drug causes emesis in 50% of dogs and 90% of cats?
- Alpha 2 Agonists (Xylazine & Medetomidine)
- What is the reversing agent for Xylazine? How is it administered?
- Yohimbine, given IV
- What are some contraindications for Alpha 2 Agonists?
- pediatric, geriatric, pregnant, sick, diabetic, cardiovasular or resp dz, GI obstruction
- How is Xylazine administered?
- IM or IV
- How long is the period of analgesia provided by Xylazine? The sedation?
- 20 minutes for anagesia, up to several hours for sedation
- With Medetomidine there is a longer period of duration, but sudden ___ has been reported
- arousal
- What is the reversing agent for Medetomidine? How is is given?
- Atipamezole, given IM
- Reversing Alpha 2 Agonists do/do not reverse other drug that were given simultaneously
- do not
- When reversing an Alpha 2 Agonist, addtl pain med may be needed - why?
- It is the Alpha 2 Agonist that is providing the analgesia in many cases - if reversed you need to administer something to take over that function
- What are opioids derived from?
- opium poppy
- Opioids are a common component of preanesthetic protocols - why?
- safe for high risk pts and provide excellent analgesia for painful surgeries
- What are the most effective analgesics known?
- Opioids
- An opioid mixed w/ a tranquilizer for arousable but profound sedation/analgesia is an example of what?
- Neuroleptanalgesia
- What are three common uses for opioids
- preanesthetic, postoperative pain, and neuroleptanalgesia
- What are some advantages of opioids?
- most eff analgesia known, potent sedation, reversible, wide margin of safety
- With opioids, they are given IV w/ caution in dogs, but you should avoid IV route in ___
- cats
- What are the four types of opioid receptors?
- Kappa, Mu, Sigma, Delta
- What effects does the opioid receptor Kappa control?
- Analgesia & cardiovascular stimulation
- What effects does the opioid receptor Mu control?
- Analgesia, euphoria, and CV depression
- What effects does the opioid receptor Sigma control?
- Analgesia & dysphoria
- What effects does the opioid receptor Delta control
- Analgesia & motor dysfunction
- What do pure agonists do? Examples of?
- Stimulate all 4 types of receptors - morphine, oxymorphone, fentanyl
- What do mixed agonists do? Examples of?
- Stimulate some types or receptors, block others - Butorphanol
- What do pure antagonists do? Examples of?
- Block all types of receptors - Nalaxone
- What are some signs of opioid overdose?
- Profound resp depression, bradycardia, extreme sedation or excitement, pinpoint pupils in dogs, dilated pupils in cats, facial swelling &/or hypotension due to histamine release excessive salivation
- Are opioids controlled?
- Yes
- How is morphine administered?
- SC, PO, slow IV (dogs only), IM
- What is the duration of morphine?
- about 2 hours
- ___ is the standard by which other opioids are compared
- Morphine
- Is morphine expensive?
- No
- How is Oxymorphone administered?
- IV, IM, SC(cats), epidural
- Hydromorphone is more or less expensive than Morphine? Than Oxymorphone?
- More expensive than Morphine but less expensive than Oxymorphone
- What are some benefits of Oxymorphone over Morphine? Disadvantage?
-
Adv - longer duration (~4 hrs), more potent sedation & analgesia, fewer side effects
Disadv - more expensive - Hydromorphone is more/less potent than oxymorphone, more/less expensive, and has duration and side effects similar to morphine
- slightly less potent, less expensive
- Butorphanol provides minimal sedation, analgesia for ____ hours, has a __ safety index, but is ___
- analgesia for 1-2 hours, high safety index, is expensive
- How are opioid reversants administered?
- IV, sublingual for neonates
- The reversant Nalorphine is __% antagonistic
- 90%
- The reversant Naloxone is __% antagonistic
- 100%
- The opioid Fentanyl is administered how? For what?
- By transdermal patch for postoperative pain