1)     RECOMMENDATIONS

a)      General Approach

i)        Minimize overall systemic effect

b)      Pre-anesthetic Medications

i)        Dogs

(1)   Oxymorphone, hydromorphone, methadone, or fentanyl

(a)    Doses

(i)      Oxymorphone 0.05 mg/kg (0.025 mg/lb) IM

(ii)    Hydromorphone 0.1 mg/kg (0.05 mg/lb) IM

(iii)   Fentanyl 0.005 mg/kg (0.0025 mg/lb) IM

(2)   May be combined with midazolam or diazepam

(a)    Doses

(i)      Midazolam 0.1 to 0.2 mg/kg (0.05 to 0.1 mg/lb) IV or IM

(ii)    Diazepam 0.1 to 0.2 mg/kg (0.05 to 0.1 mg/lb) IV (IM use not recommended)

ii)       Cats

(1)   Pre-medicate with one of these combinations:

(a)    Hydromorphone 0.1 mg/kg (0.05 mg/lb) combined with midazolam 0.2 mg/kg (0.1 mg/lb) IM

(b)   Butorphanol 0.2 mg/kg (0.1 mg/lb) combined with midazolam 0.2 mg/kg (0.1 mg/lb) IM

(c)    Ketamine 2 to 6 mg/kg (1 to 3 mg/lb) with butorphanol 0.2 mg/kg (0.1 mg/lb) and midazolam 0.2 mg/kg (0.1 mg/lb) IM

(i)      Particularly useful for fractious debilitated cats

(ii)    Avoid ketamine if intracranial disease is suspected or if myocardial stress is a concern

c)      Induction

i)        Preoxygenate whenever possible if not overly stressful to the patient

ii)       Hydromorphone, oxymorphone, or fentanyl with diazepam IV

(a)    More suitable for dogs than cats

(b)   See induction section for details

iii)     Propofol

(1)   Dogs - use ultra-low-dose technique starting with 1.0 mg/kg (0.5 mg/lb) propofol slowly IV over 30 to 60 seconds followed by 2 mg/kg (1 mg/lb) lidocaine IV then 0.5 to 1.0 mg/kg (0.25 to 0.5 mg/lb) boluses of propofol given slowly IV to effect

(2)   Cats - use ultra-low-dose technique starting with 1.0 mg/kg (0.5 mg/lb) propofol slowly IV over 30 to 60 seconds followed by 0.5 to 1.0 mg/kg (0.25 to 0.5 mg/lb) boluses of propofol given slowly IV to effect

iv)     Ketamine & diazepam

(1)   An alternative choice for debilitated cats that can tolerate the myocardial effects of ketamine

(2)   Induction dose

(a)    1 cc/20 lb. of a 50/50 mix

(i)      Start with 1/4 to 1/2 of calculated dose, then small boluses to effect

d)      Maintenance

i)        Isoflurane or sevoflurane

ii)       Hydromorphone or oxymorphone & diazepam

(1)   Repeat hydromorphone or oxymorphone every 20 to 30 minutes and diazepam every 40 to 60 minutes for maintenance

(2)   This is primarily a canine appropriate protocol

(3)   See details in Anesthetic Maintenance Section

e)      Support

i)        Fluids

(1)   Maintenance of adequate hydration is very important

ii)       Colloids followed by dobutamine – if needed - for blood pressure management

(1)   See details in Blood Pressure Management section

2)     PRECAUTIONS

a)      Pre-anesthetic Medications

i)        Morphine Sulfate

(1)   Can cause nausea, transient hypotension

b)      Induction

i)        Avoid rapid propofol administration

(1)   Can cause apnea, myocardial depression and hypotension

ii)       Avoid ketamine if intracranial disease or if significant myocardial disease is suspected

c)      Maintenance

i)         If blood pressures are not stable under isoflurane or sevoflurane, consider intermittent hydromorphone or oxymorphone boluses with intermittent diazepam boluses

(1)   See Anesthetic Maintenance Section for details

d)      Support

i)         Focus on:

(1)   Blood pressure management

(2)   Body temperature maintenance

(a)    Coordinate warm water blanket with warm air patient warmer

(3)   Adequate ventilation

(a)    Monitoring ETCO2 is highly recommended