Levobupivacaine versus ropivacaine in psoas compartment block and sciatic nerve block in orthopedic surgery of the lower extremity.

Aim: The aim of this study was to compare the clinical profiles of psoas block and sciatic nerve block performed with either 0.5% levobupivacaine or 0.75% ropivacaine.
Methods: With ethical committee approval and written informed consent 80 ASA physical status I-II patients, undergoing lower extremity surgery received intravenous premedication with midazolam (0.05 mg/kg) and atropine (0.01 mg/kg). Patients were randomly allocated to receive a lumbar plexus block with: Levobupivacaine Group (L) 30 ml of 0.5% levobupivacaine or Ropivacaine Group (R) 0.75% ropivacaine, and sciatic nerve block with: Group R 10 ml 0.75 ropivacaine or Group L 0.5% levobupivacaine. The onset time and duration of nerve block were evaluated.
Results: The motor onset time was shorter in Group L than in Group R. The motor offset time was similar in the 2 groups, the time being slightly greater for Group R. Group L presented a higher difference of resolution to motor-sensitive block compared to Group R.
Conclusions: The differences between Groups L and R were characterised by: a faster motor onset time in Group L with a longer time between motor and sensitive resolution determining a lower demand for analgesic drugs postoperatively and greater support for motor control recovery.