Additivazione all'anestesia generale di blocchi locoregionali sugli arti in corso di chirurgia ortopedica canina : effetto analgesico della ropivacaina

Aim of this study was to evaluate the analgesic effect of ropivacaine(RPV) and bupivacaine (BPV) used for regional limb blockade, in anaesthetised dogs undergoing orthopaedic procedures localised distally to the scapula or hip. For the forelimb, brachialis plexus blockade was performed at a level of ventral branches of C6-C7-C8-T1. For the rearlimb, lumbosacral plexus blockade was performed at a level of ventral branches of lateral cutaneous femoral, femoral and obturator nerves (L4-L5), ischiatic (L5-L6-L7-S1-S2), pudendal and caudal cutaneous femoral nerves (S1-S2). A nerve locator guided technique was used in all the procedures. Analgesic effect of RPV (2 mg kg-1) was evaluated in 10 dogs (RPV group). All physiological parameters (HR, RR, NIBP, T°, SpO2, ETCO2, ECG), and evaluation of acute postsurgical pain (modified from Melbourne scale) (Gaynor & Muir, 2002), were compared with those obtained by BPV (2 mg kg-1) in the other 10 dogs (BPV group). The data was statistically analysed by ANOVA and t test (P< 0.05). Results. Monitored parameters during anaesthesia did not show statistically significant differences between groups. Recovery time values in RPV group (10 ± 6.24; 18.20 ± 9.78; 34.50 ± 21.02) compared with those in BPV group (9.30 ± 5.14; 23.20 ± 17.13; 82.11 ± 70.19) resulted not to be statistically different. Pain scores in RPV group (0.2 ± 0.63; 0 ± 0; 0.25 ± 0.71) compared with those in BPV group (0.3 ± 0.67;0.3 ± 0.67; 1±1.07) did not show statistical differences. When using effect of regional limb blockade in dogs undergoing orthopaedic surgery ropivacaine seems to be as efficient as bupivacaine.