Clinical effects of epidurally administered dexmedetomidine with or without lidocaine in sheep

Abstract

BackgroundThe aims of this study were evaluate cardiopulmonary, sedative and antinociceptive effects of dexmedetomidine–lidocaine combination via lumbosacral epidural injection in sheep.MethodsSix Santa Inês breed sheep, 16±6 months old and weighing 42.2 ± 5.7 kg were used. Sheep were subjected to epidural anaesthesia with three treatments: L, lidocaine (1.2 mg/kg), D, dexmedetomidine (2.5 μg/kg) or DL, dexmedetomidine plus lidocaine (2.5 μg/kg + 1.2 mg/kg). Drugs were injected via pre-placed lumbosacral epidural catheters. Cardiopulmonary, arterial blood gases, electrolytes, degree of sedation and antinociceptive aspects were measured before drug administration (T0) and then at 15, 30, 60 and 120 min after drug injection (T15–T120) in all treatments and at T0 to T240 in DL.ResultsThere were significantly increases in PaCO2 at times T60 and T120 in D, and at T30–T120 in DL, compared to baseline. The antinociceptive effects were observed up to 240 min in DL and 60 min in L, and were more intense in DL. Treatment D provided analgesia only in the perineal region, and only at T15.ConclusionThe combination of DEX with lidocaine produced similar cardiopulmonary changes compared with either drug alone, but with greater and more prolonged antinociceptive effects.

Pharmacokinetic and Pharmacodynamic Drug–Drug Interactions: Research Methods and Applications

“…The combination of narcotics and analgesics is commonly assessed using an in vivo approach. The feasibility of this combination is determined by comparison with results from a positive control group [ 81 , 82 ]. Stemmet et al compared a combination of anesthetics, analgesics, and sedatives with preferred etorphine and azaperone, using invasive blood pressure and blood gas analysis [ 83 ].…”