Magnesium as an adjuvant for caudal analgesia in children

Abstract

BACKGROUND: There is a need for an adjuvant agent of caudal block that prolongs

its duration and improves the analgesic efficacy to fasten functional recovery.

Magnesium is an N-methyl-D-aspartate receptor antagonist that functions as an

analgesic. This study was aimed to evaluate whether magnesium as an adjuvant for

caudal block in children can improve postoperative analgesia and functional

recovery. METHODS: Eighty children, 2-6 years of age, undergoing inguinal

herniorrhaphy, were included in this prospective, randomized, double-blinded

study. For caudal block, Group R received ropivacaine 1.5 mg.ml(-1), 1 ml.kg(-1)

and Group RM received the same dose of ropivacaine mixed with 50 mg of magnesium.

The Parents' Postoperative Pain Measure (PPPM) score, analgesic consumption,

functional recovery, and adverse effects were evaluated at 6, 24, 48, and 72 h

after surgery, as well as daily thereafter until the child showed full functional

recovery. RESULTS: The PPPM score after hospital discharge was significantly

lower for Group RM than for Group R at all times (P < 0.05). Children in Group RM

required less fentanyl for rescue analgesia in the recovery area (16.2% vs 39.5%,

P = 0.034) and less oral analgesics after discharge (20.5% vs 52.6%, P = 0.007).

The time to return of normal functional activity was shorter in Group RM (P <

0.05). The incidence of adverse effects did not differ between groups.

CONCLUSIONS: As an adjuvant for caudal analgesia, 50 mg magnesium provided

superior quality of analgesia and faster return of normal functional activity

than local anesthetic alone in children.