Dexmedetomidine Versus Clonidine in TAP Block

• Status: Completed
• Trial end date: 2019-08-01
• Target enrollment: 0
• Participant gender: Male

Summary

A laparoscopic approach offers several advantages over an open procedures; potentially reduces the surgical stress and fluid shifts that may accompany it; in addition there is less need for postoperative analgesia, reduction of postoperative respiratory and wound complications.

Despite the minimally invasive nature, pain can be moderate to severe in the immediate postoperative period that requires multimodal analgesia. Inadequate control of post-operative pain leads to several unwanted adverse events ranging from patients' discomfort and prolonged immobilization to thromboembolic phenomenon and pulmonary complications.

Transversus abdominis plane (TAP) block is a type of peripheral nerve block that involves innervation of the anterolateral abdominal wall. With the aid of ultrasound, local anesthetic (LA) is injected into the transversus abdominis fascial plane, where the nerves from T6 to L1 are located.

Ultrasound TAP block is accompanied by a good pain relief and reduced intraoperative and postoperative opioids requirements after laparoscopic surgery. In this case a bilateral TAP block is necessary because the abdominal skin incisions for the ports of laparoscopic procedure are performed on both sides.

Unfortunately, TAP block duration is limited to the effect of administered LA. Recently, adjuvant medications were added to LA to prolong the effect of TAP block. Dexmedetomidine is a selective alpha 2 (α2) adrenergic agonist with both analgesic and sedative properties. Its use with bupivacaine either epidurally or intrathecally is associated with prolongation of the LA effect. A major advantage of dexmedetomidine is its higher selectivity compared with clonidine for α2A receptors, responsible for the hypnotic and analgesic effects of such drugs.10 Clonidine action, similar to local anesthetic action, and its interaction with local anesthetics have been explained by three possible mechanisms. First, clonidine blocks Ad and C fibers. Secondly, clonidine may cause local vasoconstriction, thus decreasing local anesthetic spread and removal around neural structures. Thirdly, clonidine used in peripheral blocks intensifies and prolongs analgesia.

• Phase: Phase 2/Phase 3
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Assiut University
• Treatments: Bupivacaine; Clonidine; Dexmedetomidine; Levobupivacaine

Criteria

Inclusion Criteria:

• ASA I-II physical status patients.

• Age between 3 and 8 years.

• Children undergoing laparoscopic orcheopexy.

Exclusion Criteria:

• Parent refusal

• History of developmental delay or mental retardation, which will make observational pain intensity assessment difficult

• Hypersensitivity to any local anesthetics

• Bleeding diathesis

• History of renal, hepatic, cardiac, upper or lower airway or neurological diseases

• Any sign of infection at the puncture site of the proposed block

• History of sleep apnea with which postoperative ventilation may be required