This prospective trial found the use of epinephrine along with ropivacaine in pregnant women to effectively increase the safety of the posterior Quadratus Lumborum Block and offer postoperative pain relief after Cesarean Section. It also prolongs the duration of anesthesia of this block.

To determine the safety and efficacy of epinephrine plus ropivacaine for bilateral posterior Quadratus Lumborum Block (pQLB) compared with bilateral pQLB using ropivacaine alone in Cesarean Section (CS).

Fifty-two pregnant women were designated to either of the two groups:

• e-pQLB group: Ropivacaine 0.375% plus epinephrine 100 mcg, 20 ml each side
• pQLB group: Ropivacaine 0.375% alone, 20 ml each side

The efficacy and safety of use of epinephrine as an adjunct therapy to ropivacaine for pQLB were assessed.

The total mean morphine use statistically lower during the first 24 post-operative hours in the e-pQLB group compared to p-QLB group (5.08 ± 3.12, versus 9.11 ± 4.67 SD mg). The patients in the pQLB group had a statistically lower score of Numeric Rating Scale (NRS) values at 6 hours from block, at rest and with movement:

Table 1: NRS scores in e-pQLB group and p-QLB group

Also, a longer time between block and the first opioid request was observed in e-pQLB group (5.92±2.48 SD hrs) versus p-QLB group (3.78±2.68 SD hrs).

The venous concentrations of ropivacaine were considerably lower at any time of samples though at 2 hours in e-pQLB group than p-QLB group.

Use of epinephrine as an adjunct therapy to ropivacaine was increased the efficacy and length of pQLB. Furthermore, the block safety was increased, with decreased peak and mean venous concentration of ropivacaine.