QLB vs mTLIP for Lumbar Spinal Surgery

The block procedure will be applied after the surgery and before extubation with patients in the prone position by using US (Vivid Q, GE Healthcare, US). Under aseptic conditions, the probe will be covered with a sterile sheath and a 22G, 80 mm block needle (Braun Stimuplex Ultra 360, Germany) will be used. After visualizing the abdominal muscles, the needle will be punctured and 5 ml of saline will be injected into the postero-lateral border of the quadratus lumborum muscle. After the block location is confirmed, 15 ml of 0.25% bupivacaine will be injected. The same process will be applied to the opposite side (30 ml totally).

US probe will be placed vertically at the L3 vertebrae level. After visualizing the hyperechoic shadow of the spinous process and interspinous muscles as an anatomical guide point, the probe will be moved forward to the lateral to visualize the longissimus and iliocostal muscles. Between these muscles, block needle will be inserted within in plane technique in a medial-to-lateral direction in the interfascial plane. Once the needle tip will be placed within the interfacial plane and after careful aspiration to rule out intravascular needle placement, 2 mL of saline will be injected to confirm the proper injection site, and then a dose of 0.25% bupivacaine 15 mL will be injected in each side (30 ml totally).