The Influence of Different Degrees of Temperature of Intrathecal Levobupivacaine on Spinal Block Characteristics in Orthopedic Surgeries: A Prospective Randomized Study.

Background And Aims: The temperature of the local anesthetics may affect the distribution of spinal anesthesia. The aim of the current study is to compare the effects of different degrees of intrathecal levobupivacaine 0.5% on the spinal anesthesia characteristics and shivering in orthopedic surgery.

Materials And Methods: A randomized, prospective, and controlled trial was conducted on 120 patients aged 40-70 years with American Society of Anesthesiologists Classes I and II and who scheduled for orthopedic surgery; they were randomly distributed into three groups: Group 1 (L 24°C) - levobupivacaine 0.5% warmed to 24°C; Group 2 (L 30°C) - levobupivacaine 0.5% warmed to 30°C; and Group 3 (L 37°C) - levobupivacaine 0.5% warmed to 37°C. Every patient had received 3 mL of 0.5% levobupivacaine intrathecally. Sensory blockade was tested using the loss of pinprick sensation, whereas the motor block was tested using the modified Bromage scale. The onset and grading of shivering after spinal anesthesia were recorded.

Results: The use of intrathecal levobupivacaine 0.5% warmed to either 30°C or 37°C resulted in a significant acceleration of the onset of either sensory or motor blockade with a significant prolongation in the duration in addition to significant delay in the onset of shivering and the time of the first analgesia requirement in comparison to those of spinal anesthesia with levobupivacaine at room temperature (24°C). Notably, a nonsignificant difference in the spinal block characteristics and shivering was observed between Group L 30°C and Group L 37°C.

Conclusion: The increasing the temperature of levobupivacaine 0.5% to 30 °C attains more rapid onset of sensory and motor blocks , with prolongation of the onset of shivering. It could be considered as effective equivalent to warming levobupivacaine 0.5%to 37°C in spinal anesthesia.