Does pethidine affect the cardiovascular and sedative effects of dexmedetomidine in dogs?
OBJECTIVE
To investigate pethidine's effects on sedation and cardiovascular variables in dogs premedicated with dexmedetomidine.


METHODS
Sixty American Society of Anesthesiologists (ASA) I dogs were presented for routine neutering. Heart rate was measured at admission. Dogs were randomly assigned to one of the five groups to decide premedication; group D5+P (dexmedetomidine 5 microg/kg plus pethidine 5 mg/kg), D10+P (dexmedetomidine 10 microg/kg plus pethidine 5 mg/kg) with three control groups, D5 (dexmedetomidine 5 microg/kg), D10 (dexmedetomidine 10 microg/kg) or P (pethidine 5 mg/kg). Heart rate was measured at 3, 5, 10 and 20 minutes after preanaesthetic medication. Simple descriptive scores for sedation were assigned after 20 minutes. Anaesthesia was induced using propofol and maintained using isoflurane in oxygen. Heart rate was recorded throughout anaesthesia.


RESULTS
Sedation scores after preanaesthetic medication were significantly higher (P<0.001) in groups D5+P and D10+P compared with the other three groups. D5+P and D10+P groups tended to have lower heart rates in dogs at all time points after premedication compared with groups containing only pethidine or dexmedetomidine at the relevant dose.


CONCLUSIONS
Greater sedation is achieved using combinations of dexmedetomidine and pethidine compared with each drug alone. Pethidine does not attenuate the alpha-2 adrenergic-induced bradycardia.
Grint
N J
NJ
Division of Veterinary Anaesthesia and Division of Equine Studies, University of Liverpool, Leahurst, Neston, Wirral, CH64 7TE, UK.
Burford
J
J
Dugdale
A H A
AH
D000759:Adjuvants, Anesthesia / Q000008:administration & dosage* / Q000009:adverse effects; D000818:Animals; D002369:Castration / Q000662:veterinary; D054810:Deep Sedation / Q000379:methods / Q000662:veterinary*; D020927:Dexmedetomidine / Q000008:administration & dosage* / Q000009:adverse effects; D004285:Dogs; D004359:Drug Therapy, Combination; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006993:Hypnotics and Sedatives / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D008614:Meperidine / Q000008:administration & dosage* / Q000009:adverse effects; D011229:Preanesthetic Medication / Q000662:veterinary; D014581:Urticaria / Q000139:chemically induced
D000759:Adjuvants, Anesthesia; D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine; D008614:Meperidine