Ropivacaine Plasma Concentration With or Without Epinephrine for Posterior Quadratus Lumborum Block

Introduction The posterior Quadratus Lumborum Block (pQLB) has been used in postoperative pain management after Cesarean Section (CS). However, there are no data about pQLB safety in pregnants, at increased risk of local anesthetic systemic toxicity (LAST). The purpose of the present study was to explore the efficacy and the safety of adding epinephrine to ropivacaine for bilateral pQLB vs. bilateral pQLB performed with ropivacaine alone in CS. Methods Fifty-two pregnants were consecutively allocated to one of 2 groups \[e-pQLB (0.375% ropivacaine+100 mcg epinephrine) or pQLB (0.375% ropivacaine)\] and the investigators evaluated if the adjunct of epinephrine to ropivacaine increases of efficacy (measured as opioid consumption during the first 24 postoperative hours, time for first request of opioid and pain values reported by patients) and the safety (measured as peak and plasmatic concentration of ropivacaine) of pQLB.