Effects of temperature and different doses of flumazenil on sedation induced by midazolam in bearded dragons (Pogona vitticeps).

OBJECTIVE

To evaluate the effects of optimal versus suboptimal sedation/anesthesia temperature and two flumazenil doses, on sedation induced by subcutaneous (SC) midazolam in bearded dragons (Pogona vitticeps).

STUDY

DESIGN

Prospective, randomized, experimental, crossover study.

ANIMALS: A group of eight (five males and three females) bearded dragons.

METHODS

All bearded dragons (13-14 months old) received four treatments. All treatments involved SC midazolam (1 mg kg-1) injected cranial to a forelimb and occurred under optimal temperature (28-32 °C) (MO: midazolam + saline; MFL: midazolam + flumazenil 0.05 mg kg-1; MFH: midazolam + flumazenil 0.1 mg kg-1) or suboptimal temperature (18-20 °C) (MS: midazolam + saline). Animals were video-recorded before (T0) and for 180 minutes post-injection (T10-T180). A blinded observer scored sedation (scale 0-12). Scores were compared within treatments (Friedman and Dunn's test) and between treatments (Wilcoxon; Friedman with post hoc). Loss of righting reflex (LORR), heart rate (HR) and respiratory rate were reported descriptively.

RESULTS

A median difference of up to 3 was observed between MO and MS, but all p values were > 0.08, though LORR occurred in 6/8 animals only during MS. Flumazenil reduced sedation, but median difference between MFL and MFH scores did not exceed 1, with all p > 0.63. The lowest median HR (beats minute-1) observed were 34 for MO, 40 for MFL, 44 for MFH, and 19 for MS.

CONCLUSIONS AND CLINICAL RELEVANCE: Midazolam (1 mg kg-1 SC) induces moderate sedation in bearded dragons. Suboptimal sedation/anesthesia temperature does not produce clinically relevant difference in sedation scores compared with optimal temperature and exacerbates bradycardia. Flumazenil (0.05 mg kg-1) reduces sedation scores. Increasing flumazenil from 0.05 mg kg-1 to 0.1 mg kg-1 does not add any benefit.