The analgesic effects of ropivacaine in ilioinguinal-iliohypogastric nerve block in children--concentration or volume?

OBJECTIVES: The aim of the present study was to compare the analgesic effects of ripovacaine when used as high concentration/small volume, versus its use as high volume/low concentration, in ilioinguinal-iliohypogastric nerve block in children. METHODS: This is a prospective single-blind randomized study consisting of 72 children ASA I & II, 3-9 years of age, scheduled for outpatient elective surgery. Children were randomly assigned into two equal groups (36 each), to receive ropivacaine 0.8 mg.kg(-1), for ilioinguinal-iliohypogastsric block, either as: 1 mg.ml(-1) (0.8 ml.kg(-1)) G1 group, or 2 mg.ml(-1) (0.4 ml.kg(-1)) G2 group. The postoperative pain was assessed using the Children's Hospital of Eastern Ontario Pain Scale (CHEOPS), at the end of surgery (H0), at one (H1), tow (H2), four (H4) and six (H6) postoperative hours. Parents were requested to record their child's pain every 6 hours during the first 24 postoperative hours, using the postoperative pain measurement for Parent Scale. RESULTS: CHEOPS score H0 was significantly lower in G2 as compared to G1 group (p = 0.03). Only 2 children in G2 as compared to 8 children in G1 group, required i.v. paracetamol administration after surgery (p = 0.04). In group G1, two children required paracetamol at home and three developed a postoperative transitory femoral nerve block (p = 0.23). CONCLUSIONS: Ropivacaine when used with high concentration/small volume is more efficient than when used a high volume/low concentration, for ilioinguinal-iliohypogastric nerve block in children.