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P
1)
PROPOFOL
a)
Classification
i)
A phenol in a hyperlipid emulsion
b)
General Information
i)
A very fast acting injectable without cumulative effect
c)
Advantages/Recommended use
i)
Generally for:
(1)
Cases when rapid recovery is desired
(2)
Diabetes Mellitus
(a)
Propofol is capable of providing a smooth and rapid return to a
comfortable state if premedications are appropriately utilized
(b)
Appetite appears increased in many patients for a short period of
time after recovery from propofol
(3)
Outpatient procedures
(4)
Sighthounds
(5)
C sections
(6)
Liver disease
(7)
Giant breed dogs when early ambulation is desired
ii)
Can be given as intermittent bolus or constant rate infusion (CRI)
for maintenance of anesthesia
iii)
Can be combined with 2% Thiopental in a 50/50 ratio
(1)
Improves stability/shelf life
(a)
This combined product should be handled carefully and refrigerated
for storage
(b)
It should be used within 24 to 48 hours of the propofol’s opening
(2)
Dose at same volume you would
calculate if using propofol alone
d)
Cautionary Information
i)
Predictable respiratory depression and hypotension if given rapidly
(1)
Should not be a major concern if given slowly
ii)
Hyperlipid emulsion easily promotes bacterial growth
(1)
Once opened, must use contents within 6 - 8 hours
iii)
When use in patients with hepatic dysfunction the clearance times
may be doubled
(1)
There is some pulmonary clearance
iv)
Use caution when dealing with ill cats
(1)
Phenol can induce Heinz body anemia
(2)
This is most concerning with ongoing administration: intermittent
bolus or CRI
e)
Dosage information
i)
Routine induction
(1)
Dogs
(a)
4 to 6 mg/kg (2 - 3 mg/lb) if not depressed or sedate
(i)
Effective premeds or pre-existing CNS depression or debilitation
can reduce the dose required for intubation to 1 to 4 mg/kg (0.5 to 2
mg/lb)
(2)
Cats
(a)
6 to 8 mg/kg (3 - 4 mg/lb) if not depressed or sedate
(ii)
Effective premeds or pre-existing CNS depression or debilitation
can reduce the dose required for intubation to 1 to 4 mg/kg (0.5 to 2
mg/lb) or less
(3)
25 % slowly IV every 60 seconds to effect
(a)
Rapid administration causes:
(i)
Apnea of short duration
(ii)
Hypotension
(iii)
Reduction in myocardial contractility
(4)
If, at any point, the canine patient is nearly, but not
quite, able to be intubated, the addition of 2 mg/kg (1 mg/lb) lidocaine
IV, may deepen the anesthetic effect and facilitate successful intubation
(a)
This strategy is useful when minimizing the induction agent for
more critical patients
(b)
Cats are more sensitive to the toxic effects of lidocaine (CNS
stimulation, seizures). Lidocaine is not recommended for use in cats at
this time.
(5)
Diazepam 0.2 to 0.4 mg/kg (0.1 to 0.2 mg/lb) IV can decrease
propofol need by 50%
(6)
Routes of administration
(a)
IV
(b)
Intraosseous
ii)
Routine maintenance
(1)
Dogs
(a)
Boluses of ¼ to 1/3 of the original induction dose as needed
(b)
CRI at 0.05 to 0.4 mg/kg/minute (0.025 to 0.2 mg/lb/minute)
(i)
If too light, give 0.5 to 1.0 mg/kg (0.25 to 0.5 mg/lb) IV then
increase CRI rate by 25%
(ii)
If too deep, stop propofol until suitable anesthetic level is
reached, then reinitiate CRI at 25% lower rate
(2)
Cats
(a)
Boluses of ¼ to 1/3 of the original induction dose as needed
(b)
CRI at 0.05 to 0.2 mg/kg/minute (0.025 to 0.1 mg/lb/minute)
(i)
If too light, give 0.5 mg/kg (0.25 mg/lb) IV then increase CRI rate
by 25%
(ii)
If too deep, stop propofol until suitable anesthetic level is
reached, then reinitiate CRI at 25% lower rate
(iii)
Feline patients do not clear phenols well, repetitive day to day
use not recommended
(c)
Subsequent boluses or ongoing CRI doses should be adjusted downward
over time
(d)
Recovery will be more prolonged than with dogs
f)
Cost
i)
Moderate
R
1)
Romazicon
a)
See Flumazenil
2)
Rompun
a)
See Xylazine |
