Comparison of the effects of ketamine and fentanyl-midazolam-medetomidine for sedation of rhesus macaques (Macaca mulatta).
BACKGROUND
This study assessed the effects of sedation using a combination of fentanyl, midazolam and medetomidine in comparison to ketamine. Rhesus Macaques (Macaca mulatta), (n = 16, 5 males and 3 females randomly allocated to each treatment group) received either ketamine (KET) (10 mg.kg(-1)) or fentanyl-midazolam-medetomidine (FMM) (10 μg/kg(-1); 0.5 mg.kg(-1); 20 μg.kg(-1)) both IM. Oxygen (100%) was provided by mask and heart rate, blood pressure, respiratory rate, EtCO2 and depth of sedation were assessed every 5 min for 20 min. After the last time point, FMM monkeys were reversed with atipamezole-naloxone (0.2 mg.kg(-1); 10 μg.kg(-1)). Recovery was scored using clinical scoring scheme. Differences in physiological parameters and quality of sedation were compared using Area Under the Curve (AUC) method and either Mann-Witney or t-student tests.


RESULTS
Heart rate (beats/min) (Ket = 119 ± 18; FMM = 89 ± 17; p = 0.0066), systolic blood pressure (mmHg) (Ket = 109 ± 10; FMM = 97 ± 10; p = 0.0313), and respiratory rate (breaths/min) (Ket = 39 ± 9; FMM = 29 ± 10; p = 0.0416) were significantly lower in the FMM group. End-tidal CO2 (mmHg) did not differ between the groups (KET = 33 ± 8; FMM = 42 ± 11; p = 0.0462). Although some depression of physiological parameters was seen with FMM, the variables all remained within the normal ranges in both groups. Onset of a sufficient degree of sedation for safe handling was more rapid with ketamine (KET = 2.9 ± 1.4 min; FMM = 7.9 ± 1.2 min; p = 0.0009), but FMM recovery was faster (KET = 21.4 ± 13.4 min; FMM = 9.1 ± 3.6 min; p = 0.0379) and of better quality (KET = 1.3 ± 0.9; FMM = 7.4 ± 1.9; p = 0.0009) most probably because of the effectiveness of the reversal agents used.


CONCLUSIONS
FMM provides an easily reversible immobilization with a rapid and good recovery quality and may prove a useful alternative to ketamine.
Comparative Biology Centre, Newcastle University, Framlington Place, Newcastle Upon Tyne, NE2 4HH, UK. henri.bertrand@newcastle.ac.uk.|Faculty of Veterinary Medicine, University of Liège, Boulevard de Colonster, Liège, 4000, Belgium. henri.bertrand@newcastle.ac.uk.
Henri G M J
HG
Bertrand
Comparative Biology Centre, Newcastle University, Framlington Place, Newcastle Upon Tyne, NE2 4HH, UK.|School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK.
Yvette C
YC
Ellen
Comparative Biology Centre, Newcastle University, Framlington Place, Newcastle Upon Tyne, NE2 4HH, UK.
Stevie
S
O'Keefe
Comparative Biology Centre, Newcastle University, Framlington Place, Newcastle Upon Tyne, NE2 4HH, UK.|Institute of Neuroscience, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
Paul A
PA
Flecknell
D000762:Anesthesia Recovery Period; D000818:Animals; D054810:Deep Sedation / Q000662:veterinary; D004359:Drug Therapy, Combination; D005260:Female; D005283:Fentanyl / Q000494:pharmacology*; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D007649:Ketamine / Q000494:pharmacology*; D008253:Macaca mulatta; D008297:Male; D020926:Medetomidine / Q000494:pharmacology*; D008874:Midazolam / Q000494:pharmacology*
D006993:Hypnotics and Sedatives; D007649:Ketamine; D020926:Medetomidine; D008874:Midazolam; D005283:Fentanyl
Fentanyl; Ketamine; Medetomidine; Midazolam; Recovery macaque; Sedation