Comparison of caudal ropivacaine, ropivacaine plus ketamine and ropivacaine plus tramadol administration for postoperative analgesia in children

Abstract

Background: The aim of this study was to compare the effect of single-dose caudal ropivacaine, ropivacaine plus ketamine and ropivacaine plus tramadol in children for postoperative pain management.

Methods: Following ethics committee approval and informed parental consent, 99 ASA PS I or II children, between 1 and 10 years of age, scheduled for elective inguinal hernia repair with general anaesthesia, were recruited. After induction of anaesthesia and placement of a laryngeal mask airway (LMATM), the patients were randomly divided into three groups to receive either caudal ropivacaine alone (0.4%, 2 mg x kg(-1)) in group R (n = 32) or ropivacaine (0.2%, 1 mg x kg(-1)) plus ketamine (0.25 mg x kg(-1)) in group RK (n = 33) or ropivacaine (0.2%, 1 mg x kg(-1)) plus tramadol (1 mg x kg(-1)) in group RT (n = 34) with a total volume of 0.5 ml x kg(-1). Systemic blood pressure (SBP and DBP), heart rate (HR), peripheral O2 saturation (SpO2), respiratory rate (RR), sedation and pain scores were recorded at 5, 10, 15 and 30 min, 1, 3, 4 and 6 h following recovery from anaesthesia. Pain was evaluated by Children's Hospital of Eastern Ontario Pain Scale, and sedation with a five-point sedation test.

Results: No difference was found regarding age, weight and duration of operation between the groups (P > 0.05). No patient experienced hypotension, bradycardia or respiratory depression. Duration of analgesia was longer in group RT (1377 +/- 204 min) than group R (1006 +/- 506 min) (P = 0.001). In the tramadol group, fewer patients required supplementary analgesics in the first 24 h (P = 0.005). Sedation scores were below 2 in all groups. Incidence of postoperative nausea and vomiting was higher in group RT (eight patients) and group RK (seven patients) than group R (one patient, P = 0.032).

Conclusions: Ropivacaine (0.4%), ropivacaine (0.2%) plus ketamine (0.25 mg x kg(-1)) and ropivacaine (0.2%) plus tramadol (0.5 mg x kg(-1)) provided sufficient analgesia in children, but the duration of analgesia was longer in the RT group.