Lumbar ESPB in Hip Replacement Surgery

This is a prospective trial in patients undergoing elective hip replacement surgery.

Written informed consent will be obtained from each patient, and our study will be conducted following the tenets of the Declaration of Helsinki for medical research involving human subjects.

Before the surgery, preoperative pain severity, chronic pain severity, and ability to sit, stand, and walk will be assessed.

Each participant will be anesthetized with spinal technique and randomly allocated patients according to postoperative analgesia to the continuous epidural (Epidural) group and the continuous lumbar erector spinae plane block (ESPB) group. Both regional techniques will be continued during the first day. Investigators will measure postoperative oxycodone consumption with a patient-controlled analgesia (PCA) pump. At several points, the patients' pain at rest and during activity will be evaluated on the visual analog scale (VAS, 0-10), their quadriceps femoris muscle strength on the Lovett scale (0-5), and their ability to sit, stand upright, and walk on the Timed Up and Go test. Moreover, the patient's recovery will be assessed through the Quality of Recovery 40 (QoR-40) questionnaire on the first postoperative day.

After the patient's discharge, information regarding acute and chronic pain severity and quality of recovery will be collected during the phone interview.

• Spinal anesthesia (Procedure), also known as Subarachnoid anesthesia: Before the beginning of surgery, all patients will be anesthetized with 0.5 % hyperbaric bupivacaine (Marcaine Heavy), 1.5 - 2.5 mL solution. A pencil point spinal needle will be used.
• lumbar erector spinae plane block (Procedure), also known as ESPB: Investigators will perform the lumbar ESPB under ultrasound control at the L3 level on the ipsilateral site of the surgery. After dissection with 0.9 NaCl, we will leave a catheter in the ESP. Then, we used 0.25% bupivacaine with epinephrine (5mcg/mL), 0.4 mL per kg, up to 40 mL.
• Epidural analgesia (Procedure): After identifying the epidural space and spinal anesthesia (combined technique), a catheter will be placed in the epidural space. Investigators will give an epidural catheter a test dose of 2% lidocaine (2 mL). At the end of the surgery, the patient will receive 5 mL of a mixture containing 0.1% bupivacaine with fentanyl (2 mcg/mL).
• patient-controlled analgesia (Procedure), also known as PCA: Each participant will receive a pump with oxycodone (1mg/ml) using a patient-controlled analgesia (PCA) technique, a bolus of 1 mL, and a lockout of 5 minutes for the first postoperative day.
• Timed Up and Go test (Diagnostic test), also known as TUG: Investigators will measure the time the patient took to rise from a chair, walk three meters, turn around 180 degrees, walk back to the chair, and sit down while rotating 180 degrees. We will assess the patient before the surgery and 24 and 48 hours after hip replacement.
• neuropathic pain symptom inventory (Diagnostic test), also known as NPSI: The Neuropathic Pain Symptom Inventory (0-100; 0 denotes no pain, 100 the most severe pain) will be evaluated before the surgery and three and six months following the procedure.
• Lovett test (Diagnostic test): A physiotherapist will use the six-grade Lovett scale to measure muscle strength, in which 0 denotes no muscle contractility, and 5 denotes the complete range of motion against gravity, with full resistance. We will test this before the surgery, 24 and 48 hours after the operation.
• Visual analog scale (Diagnostic test), also known as VAS: Investigators will measure pain intensity with VAS (0-10; 0 denotes no pain, 10 maximal pain) before and after the surgery. Pain will be evaluated at rest and upon the activity.
• Quality of Recovery 40 (Diagnostic test), also known as QoR-40: Investigators will assess the quality of recovery with QoR-40 a day after the surgery, a month, and three months following the procedure. The minimal score is 40, and the maximal is 200. The higher the result, the better the quality of recovery is.
• Ability to sit, stand upright, and walk (Diagnostic test): A physiotherapist will evaluate the patient's ability to sit, stand upright, and walk at planned times.

Primary outcomes

• Opiod consumtion with PCA [From the admission to the postoperative care unit to the next postoperative day for 24 hours.]: Oxycodone consumtion used with a patient-controlled analgesia pump

Secondary outcomes

• Pain at rest [24 hours before the surgery, after the surgery immediately in the postoperative care unit, 4, 8, 24, and 48 hours following the operation]: Pain measured at rest on the VAS (0-10)
• Pain upon activity [24 hours before the surgery, after the surgery immediately in the postoperative care unit, 4, 8, 24, and 48 hours following the operation]: Pain measured upon activity on the VAS (0-10)
• Lovett test [24 hours before the surgery, 24 and 48 hours after the operation]: The quadriceps femori's muscle strength on the Lovett scale (0-5)
• TUG [24 hours before the surgery, 24 and 48 hours after the operation]: Timed Up and Go test in seconds
• QoR-40 [It will be measured 24 hours, 30 days, and three months following the surgery.]: quality of recovery 40
• NPSI [24 hours before the surgery and 3 and 6 months following the operation]: The Neuropathic Pain Symptom Inventory will be measured personally and after the discharge with a phone interview.

Sex: All, ages: 18 Years to 100 Years

Inclusion Criteria:

* primary hip replacement surgery due to coxarthrosis
* anesthetized with spinal technique
* able to use PCA pump
* having access to phone

Exclusion Criteria:

* patients taking painkillers not related to coxarthrosis;
* having active cancer,
* dementia or challenging contact with the patient;
* suffering from depression or other psychiatric disorders that required antidepressant treatment;
* consuming alcohol or recreational drug addiction;
* contraindications to the regional block.

• Hanych A, Kutnik P, Pasiak P, Zakrzewska-Szalak A, Wichowska O, Jednakiewicz M, Nogalski A, Piwowarczyk P, Borys M. Continuous lumbar erector spinae plane block as an alternative to epidural analgesia in pain treatment in patients undergoing hip replacement surgery - a prospective pilot study. Anaesthesiol Intensive Ther. 2023;55(4):272-276. doi: 10.5114/ait.2023.132517. PMID 38084571

• Paweł Piwowarczyk, M.D., Ph.D., Study chair, Medical University of Lublin