Transversus Abdominis Plane Block for Post-operative Analgesia Following Cesarean Section

Transversus Abdominis Plane Block: Ultra-sound Guided Versus the Modified Surgeon Assisted Approaches for Post-operative Analgesia Following Cesarean Section

Postpartum analgesia is a common concern after Cesarean Section (CS). The quality of postoperative recovery is improved by opioid sparing pain control approaches. The transversus abdominis plane block (TAPB) is an effective technique for postpartum analgesia after cesarean section. Pregnancy results in thinning of the internal oblique aponeurosis; with increased incidence of missing the second pop to reach the transversus abdominis plane (TAP). The classic blind approach to the TAP is associated with several complications; so, it has been largely replaced by the ultrasound-guided approach to the TAP. The ultrasound-guided approach to the TAPB was first described by Hebbart and his colleagues in 2007.Ultrasound-guided TAPB improves the success of the block, reduces the volume of local anesthetic used and prevents the potential injury of adjacent structures. Surgical approach to the TAPB was also described, it is a quick and easy approach of establishing a reliable block. The surgeon performs an intra-abdominal approach to the TAPB; by which asepsis is easily attained, visible and tactile confirmation of correct needle placement may be achieved with no risk of damage to the viscera but care must be given to avoid injury of the inferior epigastric vessels.

Compare the Transversus Abdominis Plane Block via the modified surgeon assisted approach (Study group), to the ultra-sound guided approach (Control group); as regards the post-operative analgesia following Cesarean Section.

The modified surgeon assisted approach for TAPB Before the closure of the peritoneum, TAPB will be performed; at the level of the umbilicus 8 to 10cms from the midline bilaterally. A sterile 100-mm 22-G insulated needle will be inserted perpendicular to the skin slightly directed towards the ipsilateral anterior superior iliac spine. After feeling the 2 pops of the external and the internal oblique aponeurosis by the anesthesiologist, the surgeon will confirm proper needle placement by his hand inside the abdominal cavity. The LA will be injected after negative aspiration and a bleb will be palpated by the surgeon as the injection continues. The same procedure will be repeated on the other side.

The ultra-sound guided approach for TAPB. After abdominal wall closure, the linear probe of the ultra- sound will be placed perpendicular to the skin at the mid-axillary line between the iliac crest and the costal margin; the TAP will be located between the internal oblique and the transversus abdominis muscle. A sterile 100-mm 22-G insulated needle will be inserted perpendicular to the skin and the 2 pops of the external and the internal oblique aponeurosis will be also felt. The LA will be injected after negative aspiration and its spread in the plane will be observed. The same procedure will be repeated on the other side.

TAPB will be given to parturients whether by the modified surgeon assisted approach or by the ultra-sound guided approach.

assessment of pain intensity at rest and on passive flexion of the hip and knee by the Numeric Pain Rating Score (NPRS) from 0 = no pain to 10 = worst pain. Assessment will be done at 2, 6, 12 and 24h postoperative.

parturients will be asked to report their satisfaction with pain management, assessed as 0 = weak, 1 = medium, 2 = good, 3 = very good, and 4 = excellent.

Inclusion Criteria: ASA physical status I and ∏ primigravidas aged 21-40 years BMI ˂ 40 body weight ˃ 60 kg singleton pregnancy gestational age of ≥37 weeks undergoing elective caesarean section under spinal anesthesia. Exclusion Criteria: Parturient refusal parturient with a BMI > 40 body weight < 60 kg ASA physical status ≥ III known local anesthetic (LA) allergy •contraindications to spinal anesthesia parturients who received analgesics in the past 24 hours infection at the site of the block.