Optimum Concentration of Caudal Ropivacaine & Clonidine - A Satisfactory Analgesic Solution for Paediatric Infraumbilical Surgery Pain

Abstract

Introduction: Ropivacaine is amide local anaesthetic pure S(-)enantiomer of bupivacaine. Its duration of analgesia is similar to that of Bupivacaine (in equivalent doses) but the motor block is slower in onset, less intense, shorter in duration for a given level of sensory block with lesser cardiac side effects but addition of an adjuvant like clonidine which is an imidazoline derivative has been studied for its sedative, anxiolytic and analgesic properties.

Aim: This study was aimed to show the optimum concentrations of Ropivacaine and Clonidine to maximize analgesia without side effects by evaluating its safety and efficacy.

Materials and methods: Sixty children aged 2-10 years of ASA grade 1, scheduled to undergo infraumbilical surgeries were randomly allocated to Group A & Group B of 30 each. Group A received 0.2% Ropivacaine with normal saline and Group B received 0.2% Ropivacaine and preservative free Clonidine 1μg/kg, the total volume of solution being 1ml/kg haemodynamic changes were monitored intraoperatively and haemodynamic parameters along with motor blockade, pain score and sedation score were assessed postoperatively.

Statistical analysis: Done with unpaired student t and Mann-Whitney test.

Results: The groups were comparable regarding demographic characterstics. The mean duration of analgesia was prolonged in group B (12+2.22 hours) than in group A (6.53+1.16 hours) with p-value <0.001 leading to less rescue analgesia in former group. None of the children in the groups had a pain score of ≥ 4 at the end of 2 hours. A 6.6% and 60% of group A children had score of ≥ 4 at the end of 4(th) & 6(th) hour respectively. None in Group B had a score of ≥ 4. At the end of 8(th) hour, only 6.6% of the children in Group B had a pain score of ≥ 4 whereas it was 33.33% in Group A which is statistically significant. No bradycardia or hypotension and no significant sedation.

Conclusion: Combination of Ropivacaine and Clonidine in the concentration used (0.2% ropivacaine and 1μg/kg of clonidine) can be optimal for postoperative analgesia in paediatric population.

Keywords: Motor block; Pain score; Postoperative analgesia; Sedation.

[Table/Fig-6]:

Duration of absolute analgesia (hours) after caudal block.

[Table/Fig-7]:

Sedation score in the first 2 hours after surgery.

[Table/Fig-8]:

Mean heart rate and standard deviation.

[Table/Fig-9]:

Mean arterial pressure and standard deviation.

[Table/Fig-10]:

Mean oxygen saturation and standard deviation.