Comparison of Plasma Concentrations of Levobupivacaine With and Without Epinephrine for Transversus Abdominis Plane Block Under Ultrasound.

Use of TAP blocks, decreases use of opioids and reduces pain scores during the postoperative period after surgeries involving the anterior abdominal wall. However, the information regarding the sensitive range of the blockade and its duration is still limited. Since that the area of administration is an intermuscular plane, it is possible to infer a large area of absorption. Knowing plasma concentrations is essential to balance the usefulness of this technique with potential systemic toxicity associated with its use.

As an additional effect, clinically, the use of vasoconstrictors may prolong the duration of the blockade significantly, depending on the drug used and site of administration. To date, no studies evaluating the effect of the addition of vasoconstrictor both in the plasma concentrations achieved, and the quality, extent and duration of the TAP block.