Propofol-medetomidine-ketamine total intravenous anaesthesia in thiafentanil-medetomidine-immobilized impala (Aepyceros melampus).
OBJECTIVE
To characterize a propofol-medetomidine-ketamine total intravenous anaesthetic in impala (Aepyceros melampus).


METHODS
Prospective clinical study.


METHODS
Ten adult female impala.


METHODS
Impala were immobilized at 1253 m above sea level with 2.0 mg thiafentanil and 2.2 mg medetomidine via projectile darts. Propofol was given to effect (0.5 mg kg-1boluses) to allow endotracheal intubation, following which oxygen was supplemented at 2 L minute-1. Anaesthesia was maintained with a constant-rate infusion of medetomidine and ketamine at 5 μg kg-1hour-1and 1.5 mg kg-1hour-1, respectively, and propofol to effect (initially 0.2 mg kg-1minute-1) for 120 minutes. The propofol infusion was titrated according to reaction to nociceptive stimuli every 15 minutes. Cardiopulmonary parameters were monitored continuously and arterial blood gas samples were analysed intermittently. After 120 minutes' maintenance, the thiafentanil and medetomidine were antagonized using naltrexone (10:1 thiafentanil) and atipamezole (5:1 medetomidine), respectively.


RESULTS
All impala were successfully immobilized. The median dose [interquartile range (IQR)] of propofol required for intubation was 2.7 (1.9-3.3) mg kg-1. The propofol-medetomidine-ketamine combination abolished voluntary movement and ensured anaesthesia for the 120 minute period. Propofol titration showed a generally downward trend. Median (IQR) heart rate [57 (53-61) beats minute-1], respiratory rate [10 (9-12) breaths minute-1] and mean arterial blood pressure [101 (98-106) mmHg] were well maintained. Arterial blood gas analysis indicated hypoxaemia, hyper- capnia and acidaemia. Butorphanol (0.12 mg kg-1) was an essential rescue drug to counteract thiafentanil-induced respiratory depression. All impala regurgitated frequently during the maintenance period. Recovery was calm and rapid in all animals. Median (IQR) time to standing from antagonist administration was 4.4 (3.2-5.6) minutes.


CONCLUSIONS
A propofol-medetomidine-ketamine combination could provide adequate anaesthesia for invasive procedures in impala. The propofol infusion should begin at 0.2 mg kg-1minute-1and be titrated to clinical effect. Oxygen supplementation and airway protection with a cuffed endotracheal tube are essential.
Department of Companion Animal Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa. Electronic address: roxanne.buck@up.ac.za.
Roxanne K
RK
Buck
Department of Paraclinical Science, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa.
Leith R C
LRC
Meyer
Department of Companion Animal Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa.
George F
GF
Stegmann
Small Animal Clinic, University of Veterinary Medicine Hannover, Hannover, Germany.
Sabine B R
SBR
Kästner
Zoo Wuppertal, Wuppertal, Germany.
Maya
M
Kummrow
Small Animal Clinic, University of Veterinary Medicine Hannover, Hannover, Germany.
Christina
C
Gerlach
Department of Production Animal Science, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa.
Geoffrey T
GT
Fosgate
Department of Companion Animal Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa.
Gareth E
GE
Zeiler
D058669:Adrenergic alpha-2 Receptor Antagonists / Q000008:administration & dosage; D000771:Anesthesia, Intravenous / Q000379:methods / Q000662:veterinary*; D019162:Anesthetics, Combined / Q000008:administration & dosage*; D000818:Animals; D000866:Antelopes; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors; D006339:Heart Rate / Q000187:drug effects; D006993:Hypnotics and Sedatives / Q000008:administration & dosage* / Q000037:antagonists & inhibitors; D007093:Imidazoles / Q000008:administration & dosage; D007649:Ketamine / Q000008:administration & dosage*; D020926:Medetomidine / Q000008:administration & dosage* / Q000037:antagonists & inhibitors; D009271:Naltrexone / Q000008:administration & dosage; D009292:Narcotic Antagonists / Q000008:administration & dosage; D015742:Propofol / Q000008:administration & dosage*; D011446:Prospective Studies; D056152:Respiratory Rate / Q000187:drug effects
C447560:A3080; D058669:Adrenergic alpha-2 Receptor Antagonists; D019162:Anesthetics, Combined; D006993:Hypnotics and Sedatives; D007093:Imidazoles; D009292:Narcotic Antagonists; C050701:atipamezole; D009271:Naltrexone; D007649:Ketamine; D020926:Medetomidine; D005283:Fentanyl; D015742:Propofol
Aepyceros melampus, impala; ketamine; medetomidine; propofol; total intravenous anaesthetic