Morphine as an Adjunct in Sonar Guided Transversus Abdominis Plane Block for Postoperative Analgesia in Patients Undergoing Abdominal Surgery.

The transversus abdominis plane (TAP) technique, originally described by involves injection of local anaesthetic in the plane between the internal oblique and transversus abdominis muscle layers, with the aim of anaesthetising the intercostal nerves supplying the abdominal wall. Initially, the block used surface landmarks of the triangle of Petit (latissimus dorsi posteriorly, external oblique superiorly, iliac crest inferiorly) and a double fascial 'pop' (loss of resistance) to guide placement of the local anaesthetic. More recently, ultrasonography has been used to guide the delivery of the injectate into the appropriate plane, thereby increasing the accuracy of the Technique.

The duration of the TAB is limited to effect of administered local anesthetics. To prolong the block's duration, adjuvant medications were added to LA to magnify the effect of TAP block . Opiates such as morphine and tramadol have peripheral and central analgesic effects. Opiate receptors are present at the terminals of afferent peripheral nerves; therefore, administration of opiates peripherally might provide a significant analgesic effect.