Anterior Quadratus Lumborum Block Versus Erector Spinae Plane Block After Elective Cesarean Section

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.

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

Eligibility Criteria:
Inclusion Criteria:

* full-term, singleton, pregnant women,
* aged 18-35 years,
* scheduled for elective cesarean delivery under spinal anesthesia

Exclusion Criteria:

* American Society of Anesthesiologists (ASA) physical class III or more
* multiple gestation.
* Patients with a history of allergy to any of the study drugs, ,
* coagulopathy,
* local infection,
* history of chronic pain or
* regular opioid use;
* inability to comprehend the numeric pain scale (NRS);
* and requirement for conversion to general anesthesia after spinal anesthesia