Anterior Quadratus Lumborum Block Versus Erector Spinae Plane Block After Elective Cesarean Section
Condition: Cesarean Section; Postoperative Analgesia
Study type: Interventional

Summary: 
      Cesarean section is the one of the most common surgical procedures. Inadequate pain
      management is associated with increased morbidity, costs, and maternal dissatisfaction.
      Furthermore, effective postoperative pain management enables mothers to care for their
      newborn infants. Systemic and neuraxial opioids are the cornerstone of postoperative pain
      management; however, opioids are associated with significant side effect such as respiratory
      depression, urine retention, constipation, and itching. To reduce the postoperative opioids
      requirement and subsequently their side effects, multimodal regimen is advice including
      neuraxial anesthesia, neuraxial morphine, regular administration of non-opioids analgesia
      (non-steroidal anti-inflammatory drugs and acetaminophen) and planned use of opioid for
      breakthrough pain.

      The addition of peripheral nerve blocks to the multimodal analgesic plan was found to reduced
      postoperative opioids requirement in non-obstetric procedures.

      Quadratus lumborum (QLB) and erector spinae plane (ESPB) blocks are relatively new techniques
      for peripheral nerve block and showed promising results in managing pain after Cesarean
      delivery.

      There are several types of QLB that had been described. Lateral (QLB1), posterior (QLB2), and
      anterior (QLB3) quadratus lumborum blocks been studied in cesarean delivery and were found to
      reduce opioids requirement when compared against placebo. Cadaver studies suggest that local
      anesthetic deposition at QLB1 diffuses mainly to the transversus abdominis muscle plane
      while, at QLB2, and at QLB3 spread may occur into the thoracic paravertebral space providing
      additional visceral pain control.

      ESPB can provide both visceral and somatic analgesia due to anterior spread to the
      paravertebral space. ESPB was found to reduce postoperative opioids requirement in comparison
      to transversus abdominis plane block and intrathecal morphine.

      To the best of our knowledge, there is no published data comparing the analgesic effect of
      QLB3 (anterior QL) and ESPB after elective cesarean delivery.
    

Detailed description: 
      Upon arrival to the operating room, routine monitors (electrocardiogram, pulse oximetry, and
      non-invasive blood pressure monitor) will be applied; intravenous line will be secured, and
      pre-medication drugs will be delivered (metoclopramide 10 mg, and ranitidine 50 mg). Lactated
      Ringer's co-load will be rapidly infused at a rate of 15 mL.Kg-1 over 10 minutes.

      Spinal anesthesia will be achieved by injecting 2.0 to 2.3 mg hyperbaric bupivacaine 0.5%
      plus 25 mcg fentanyl in L3-L4 or L4-L5 interspace.

      The spinal block will be performed in the sitting position using a 25G spinal needle through
      midline approach. The participant will be then positioned supine with left-lateral uterine
      tilt. Pinprick was used for evaluation of block success 5 minutes after intrathecal
      injection. Successful block was confirmed if sensory block level was at T4 at least.

      After skin closure and the covering of the wound with a dressing, patients received
      intravenous paracetamol (1 g) and ketorolac (30 mg).

      Spinal block height will be assessed at the end of surgery to ensure enough anesthesia at the
      site of block performance. If the site of needle entry was not anesthetized, a local
      infiltration with 2ml of 20% lidocaine will be injected prior to the block. Patients will be
      blinded to block allocation using the surgical drapes to occlude their view. The patient will
      be into the lateral position and the back will be prepared in an aseptic manner.

      after the end of the procedure the patients will receive their assigned intervention The
      blocks will be performed by experienced operator who will be informed of the patient group
      after patient positioning. The patient and the assessor of the block will be blinded to the
      study group.

      Postoperative care All patients will receive parenteral paracetamol 1 g/6hours and ketorolac
      30 mg/8hours postoperatively. Pain assessments using numerical rate scale (NRS) will be
      performed at rest and during movement (knee flexion) at 0.5, 1, 2, 4, 6, 18, 24 h after
      leaving the operating room. If NRS score is > 3 intravenous titration of 2 mg morphine given
      slowly to be repeated after 30 minutes if pain persisted. if other opioid given, the morphine
      equivalent dose will be calculated from the opioid conversion chart.

      All scores will be assigned by each patient with the assistance of an anesthesiologist not
      responsible for the surgical intervention.

      Intravenous ondansetron 4 mg will be given to treat nausea or vomiting. Complications:
      nausea, vomiting, itching, urine retention, sedation Age, weight, height and body mass index,
      duration of pregnancy, parity and gravity
    

Intervention name(s): Quadratus lumborum block; erector spinae plane block
Intervention type(s): Other; Other
Intervention description(s): quadratus lumborum block, anterior approach using a curvilinear (5-8MHz) transducer. The transducer will be positioned transverse above the iliac crest at the posterior axillary line and slided posteriorly till the Shamrock sign is identified (the transvers process represent the stem and the attached erector spinae, QL and Psoas major muscles represent the three leaves). A 22 G, 100 mm needle will be advanced in-plane from lateral to medial through the QL muscle to reach the inter-fascial plane between the QL and psoas major muscles, posterior to the transversalis fascia. After ensuring negative aspiration, the local anesthetic solution (20 ml of 0.25% isobaric bupivacaine) will be injected anterior to the QL muscle. The procedure will be repeated on the opposite side of the back; the block will be given at the level of the 9th thoracic transverse process using a linear 6-13 MHz ultrasound transducer. The transducer will be positioned vertically 3 cm to the side of the midline to visualize the muscles of the back, the transverse process, and the pleura between the two transverse processes. Then, a 22G 10-mm needle will be introduced in the cranial-caudal direction toward the transverse process (T9) using the in-plane method till the needle tip crosses all the muscles. The tip of needle should be in the plane between the transverse process and the erector spinae muscle. After ensuring negative aspiration, the local anesthetic solution (20 ml of 0.25% isobaric bupivacaine) will be injected below the muscle. The procedure will be repeated on the opposite side of the back
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary purpose: Prevention