Comparison of the effects of ketamine and fentanyl-midazolam-medetomidine for sedation of rhesus macaques ( Macaca mulatta )

摘要

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. Conclusion FMM provides an easily reversible immobilization with a rapid and good recovery quality and may prove a useful alternative to ketamine.