Background and aims Erector spinae plane (ESP) block is a promising continuous postoperative analgesia method for lower extremity.^1,2 Our aim was to demonstrate the efficacy of ESB block for postoperative analgesia in knee replacement and report our preliminary results.

Methods We planned to randomly assign patients to two groups: ESP group and epidural group. An ESP catheter was planned to be placed in the ESP group and an epidural catheter in the Epidural group for continuous postoperative analgesia. After ethical board approval we performed a pilot study that we have included only the patients that ESP catheter was placed. The catheters have been withdrawn after 24 hours postoperatively. Pain was assessed by patients using numerical rating scale between 0 and 10 at 1st, 2nd, 4th, 6th, 12th and 24th postoperative hours (POH).

Results There were 23 patients of ESP catheterization who were operated under spinal anesthesia. First consecutive 10 patients received an initial bolus of bupivacaine 0.25% 32.5±12.07 ml and continued with 10 ml boluses of bupivacaine 0.25% 3 times a day. We increased bupivacaine concentration to 0.375% for the next consecutive 13 patients with 36.91±3.87 ml initial dose. No complications were observed. NRS scores are summarized in the table 1 below.

Conclusions Our pilot study showed that ESP catheterization for continuous postoperative analgesia is feasible and can provide sufficient analgesia when administered as a part of multimodal analgesia. Its superiority over the epidural technique and optimal dosing of local anesthetics needs further research.