Cardiovascular effects of constant rate infusions of lidocaine, lidocaine and dexmedetomidine, and dexmedetomidine in dogs anesthetized at equipotent doses of sevoflurane

摘要

This study evaluated the cardiovascular effects of a constant rate infusion (CRI) of lidocaine, lidocaine and dexmedetomidine, and dexmedetomidine in dogs anesthetized with sevoflurane at equipotent doses. Treatments consisted of Tl-Lidocaine [loadingdose 2 mg/kg body weight (BW), IV, and CRI of 100 u,g/kg BW per min] at 1.4% end-tidal of sevoflutane (FESFV); T2-Dexmedetomidine (loading dose 2 u,g/kg BW, IV, and CRI of 2 |xg/kg BW per hour) and FESEV 1.1%; and T3-Lidocaine-Dexmedetomidine using thesame doses of Tl and T2 and FESFV 0.8%. Constant rate infusion of lidocaine did not induce any cardiovascular changes; lidocaine and dexmedetomidine resulted in cardiovascular effects similar to dexmedetomidine alone. These effects were characterized bya significant (P < 0.001) decrease in heart rate, cardiac output, cardiac index, oxygen delivery, and pulmonary vascular resistance index, and a significant (P < 0.001) increase in mean and diastolic arterial pressure, systemic vascular resistance index,pulmonary arterial occlusion pressure and oxygen extraction ratio, compared with baseline values. In conclusion, a CRI of lidocaine combined with dexmedetomidine produces significant cardiovascular changes similar to those observed with dexmedetomidinealone.