Oral Sedation Flashcards
What is the active metabolite of Trazodone?
m-chlorophenylpiperazine
What 3 injectable agents can be given oral transmucosal for oral sedation? Why are they commonly given at high doses?
- Acepromazine
- Dexmedetomidine
- Buprenorphine
part of them are expected to be swallowed and undergo significant hepatic first-pass metabolism
What is the mechanism of action of Trazodone? What causes the sedation?
blocks serotonin reuptake into presynaptic neurons and enhances release norepinephrine from presynaptic neurons
blocks alpha-1 adrenergic activity and antihistamine activity
What occurs with moderate doses of Trazodone?
- blocks peripheral alpha-adrenergic activity
- blocks peripheral effects of serotonin, epinephrine, norepinephrine, and histamine
What adverse effects have been noted in Trazodone usage in dogs and cats?
DOGS - sedation, increased appetite, behavioral disinhibition, vomiting, increased excitement, hepatotoicosis
CATS - drowsiness, paradoxical agitation, vocalization, GI bleeding (NOT COMMONLY USED)
What drugs is it not recommended to use Trazodone with?
other antidepressant classes
- monoamine oxidase
- serotonin-norepinephrine reuptake inhibitors
- serotonin reuptake inhibitors
(one-time dose pre-hospital is safe)
What is the use of Trazodone and SNRIs/SRIs associated with?
serotonin syndrome - agitation, restlessness, panting, hyperthermia, tachycardia, hypertension
What is thought to be the mechanism of Gabapentin? What 3 effects does it have?
binds alpha-2 subunit of voltage-gated calcium channels, which influences glutamate, norepinephrine, and substance P
- seizure control
- neuropathic pain
- sedation
Why must liquid formulation of Gabapentin be used carefully?
may contain xylitol, which is toxic to dogs and birds
What is excretion of Gabapentin important in cats?
high amounts of renal excretion —> reduce doses or there will be prolonged effect of sedation
What are the 3 important aspects of the chill protocol for aggressive and fearful dogs?
- Gabapentin (20-25 mg/kg) and Trazodone night before
- Gabapentin, Melatonin, and Trazodone morning of, 2 hours before appointment
- Acepromazine OTM 30 mins before appointment
What medications are recommended for mild sedation?
- Butorphanol
- Midazolam (sicker/older)
- Acepromazine (healthy/younger)
observation a minimum —> may need O2 and monitors
What medications are recommended for moderate sedation?
- Butorphanol
- Acepromazine
- low dose Dexmedetomidine
requires monitoring: pulse ox, BP, face mask O2, ECG
What medications are recommended for profound sedation? In cats?
- Butorphanol
- increased Dexmedetomidine
CATS: add Ketamine or Alfaxalone
requires monitoring: pulse ox, BP, face mask O2, ECG
What are the 3 most common “recipes” for at home oral sedation in cats?
- 10-40 mg/kg of Gabapentin 2-3 hours before arrival or 2 hours before handling
- Buprenorphine OTM at 0.03 mg/kg 1-2 hours before
- Buprenorphine OTM + Acepromazine OTM 2 hours before arrival
What are the 4 most common “recipes” for at home oral sedation in dogs?
- Trazodone at 5-10 mg/kg 1-2 hours before arrival (lower dose for large dogs, higher dose for small dogs)
- Gabapentin 10-20 mg/kg 2-3 hours before arrival + Acepromazine OTM 30 min before travel
- Phenobarbital at 6-10 mg/kg 2 hours before travel
- Dexmedetomidine 10-30 ug/kg OTM 20 minutes before handling
How does time affect usage of oral sedation in-hospital?
TIME PERMITTING = same options as oral at home, but may not be effective due to in-hospital nervousness
SHORT ON TIME = rectal administration of Trazodone (Gabapentin capsules are not well absorbed)
What does oral sedation aim to avoid?
- anxiety, fear, stress, pain
- high levels of induction and maintenance drugs in patients that won’t stay asleep
- injury to patient or staff
What 5 things can stress before a procedure lead to?
- autonomic, metabolic, hormonal, immunological and neuroendocrine changes
- sympatho-adreno-medullary axis activation = fight or flight; increased HR, BP, RR, catecholamines, SNS activity, arrythmias
- increased anesthetic requirements
- hypothalamic-pituitary-adrenal axis activation = prolonged stress (increased glucocorticoids)
- increased morbidity and mortality
What 3 things does prolonged stress lead to?
- sensitization to pain
- longer post-surgery recovery
- delayed healing
What issues should be considered when using chemical restraint?
- What do you need to achieve?
- How long does it need to last?
- What are underlying important issues?
- What are the CNS, cardiovascular, respiratory, and hepato-renal consequences?
What is considered mild sedation?
patient is responsive to stimulus, but less excitable/anxious, commonly used for physical exams, nail trims, and blood draws
What is considered moderate sedation? What monitoring is commonly required?
patient is recumbent, but able to change positions and react to stimuli
mask administration of O2 and monitoring highly recommended
What is considered deep sedation? What monitoring is commonly required?
MOST COMMON level of sedation used in vet med where the patient is recumbent, responds to stimuli, but is not easily aroused - laceration repair, FB removal
mask administration of O2, monitoring required; if you can intubate, you should!
Why is multimodal anesthesia/analgesia recommended?
- can be catered to specific patient needs
- allows the use of lower doses of each drug, resulting in decreased side effects
