Lumbar Paravertebral in Hernia Surgery

An inguinal hernia is one of the most common disorders requiring surgical repair in pediatrics. The effective treatment of postoperative pain in infants and children is challenging. Although the use of opioid analgesics is generally safe, adverse effects occur frequently, so the use of alternative analgesic techniques when available to improve postoperative analgesia while limiting opioid-related adverse effects, that is why there is an increase in the use of regional anesthetic techniques in infants and children.

Different anesthetic regional techniques can be used for anesthesia and analgesia of the lower abdominal surgeries such as caudal, spinal, epidural, transversus abdominis plane block, ilioinguinal nerve block, lumbar plexus block, the field block and abdominal paravertebral block. The use of regional anesthesia with ultrasound guidance can help decrease complications of regional blocks.

In the lumbar area, the lumbar paravertebral space is a potential space formed by the vertebral bodies, intervertebral discs and intervertebral foramina medially, the psoas major muscle anterolaterally and the erector spinae muscles, the transverse process and intertransverse ligaments posteriorly. There is no costotransverse ligament in the lumbar region. The lumbar spinal nerve roots run through the paravertebral space then continue through the psoas major muscle where they form the lumbar plexus.The spinal nerves in this space are devoid of a fascial sheath making them exceptionally susceptible to local anesthetics. The diaphragm and psoas muscle separate the thoracic and lumbar paravertebral areas; however, communication may occur via the medial and lateral arcuate ligaments of the diaphragm.

Field block can be done by subcutaneous injection of a local anesthetic in an area bordering on the field to be anesthetized. It is safe, simple, effective, and economical, without post anesthesia side effects. Furthermore, local anesthesia administered before the incision produces longer postoperative analgesia because of local infiltration, theoretically, inhibits the build-up of local nociceptive molecules, and therefore, there is better pain control in the postoperative period.

The aim of this study is to compare the analgesic and autonomic effects of unilateral abdominal ultrasound guided paravertebral block with field block in pediatric inguinal hernia surgery.

This study hypothesizes that unilateral abdominal ultrasound guided paravertebral block may be more superior to field block in reducing intra and postoperative pain in the pediatric inguinal hernia. The analgesic efficacy and duration of ultrasound (US) guided unilateral lumbar paravertebral block and field block were compared when dexmedetomidine and epinephrine were added as adjuvants to bupivacaine.

Eligibility Criteria:
Inclusion Criteria:

1. Patients subjected to an elective unilateral inguinal hernia repair.
2. American Society for Anesthesiologists physical status grades I and II.

Exclusion Criteria:

1. Parental refusal. 2. Neuromuscular diseases (as myopathies, myasthenia gravies, etc.) 3. Hematological diseases, bleeding or coagulation abnormality. 4. Psychiatric diseases. 5. Local skin infection and sepsis at the site of the block. 6. Known intolerance to the study drugs.

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