Dose–response of Ropivacaine Administered Caudally to Children Undergoing Surgical Procedures Under Sedation With Midazolam

Abstract

1. In a double-blind randomized controlled design, 50 children were allocated to receive bupivacaine 0.25% or ropivacaine 0.25%, 0.32%, 0.40% or 0.50% by caudal block. 2. Caudal block was performed after induction of anaesthesia with 2-5% sevoflurane, atropine 10 microg/kg and midazolam 100-300 microg/kg. During the surgical procedure, patients were maintained under spontaneous ventilation and no intravenous or inhalatory anaesthetic agent was administered. For transoperative sedation, midazolam 100-300 microg/kg was administered every 0.5-1.0 h. Transoperative cardiovascular response, postoperative analgesia and local and systemic complications were evaluated. 3. Groups were similar (P > 0.05) in sex, age, weight and in the time elapsed from caudal block to the beginning of the surgical procedure. The surgical time was significantly lower in the ropivacaine 0.25% group. The duration of analgesia was 24 h with ropivacaine 0.25% and approximately 10 h in the other four groups (P < 0.001). Linear regression analysis revealed a significant relationship between the postoperative analgesic period produced by ropivacaine and the surgical time (r = -0.48, two-sided P = 0.002). Systolic and diastolic blood pressures remained in the physiologically normal range for the duration of the transoperative period. Vomiting was present in only one patient receiving ropivacaine 0.50%. 4. In children, the duration of analgesia produced by caudal block with ropivacaine may be affected by surgical time. At surgical times of 0.5-1 h, ropivacaine 0.25% produced at least 24 h postoperative analgesia. At similar surgical times, ropivacaine 0.32%, 0.40% and 0.50% produced similar analgesic times to bupivacaine 0.25%.

New local anesthetics for pediatric anesthesia

“…In this group the postoperative pain management provided adequate analgesia and was well tolerated [15 ]. Ropivacaine 0.25% administered in children through the caudal route for various surgical procedures produced at least 24 h of postoperative analgesia [16]. For continuous peripheral nerve blocks (axillary, femoral and sciatic for major orthopedic surgery and trauma) a bolus dose of 0.5-1 ml kg À1 (depending on the nerve to be blocked) of ropivacaine 0.2% with clonidine 2 mg kg À1 has been used.…”

Evidence-based clinical update: Which local anesthetic drug for pediatric caudal block provides optimal efficacy with the fewest side effects?

“…Seventeen such RCTs were reviewed in detail using a structured methodology. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Two review articles were also identified. 18,19 The reference lists for all of these 19 publications were reviewed to identify any further RCTs that may have been missed with the initial search strategy; no such study was found.…”