Analgesic Effects of Caudal S-ketamine for Supplementation of Ropivacaine Caudal Analgesia in Children With Hypospadias

Study Overview
=================
Brief Summary
-----------------
Caudal analgesia with ropivacaine is commonly used in sub-umbilical pediatric surgery. However, increasing the dosage of ropivacaine has not been found to prolong the action significantly while complications will be serious. Ketamine as an additive to caudal administration had been shown to prolong the duration of postoperative analgesia, while the analgesic effectiveness of S-ketamine, the S(+)-enantiomer of ketamine with less possibility to induce psychomotor disturbances, is not clear. In this prospective randomized double-blind clinical trial , the investigators aimed to study the effect of S-ketamine as additive on the duration of caudal analgesia.

Detailed Description
-----------------
Forty-four children scheduled for hypospadias randomize into 2 groups. Group E (n=22) (0.2% ropivacaine 0.7 ml／kg and S-ketamine 0.5 mg/kg), group C(n=22)( 0.2%ropivacaine 0.7ml／kg and equivalent saline) intraoperative and postoperative hemodynamics will be recorded. Postoperative pain is assessed using an established 6-item FLACC score at 1h,3h,6h,12h,24h,48h, or the time when children complain of pain after surgery. A score of more15μg/kg is administered.Investigators propose to compare the duration of caudal analgesia provided by plain ropivacaine and by a mixture of ropivacaine and S-ketamine.

Official Title
-----------------
Analgesic Effects of Caudal S-ketamine for Supplementation of Ropivacaine Caudal Analgesia in Children With Hypospadias

Conditions
-----------------
Postoperative Analgesia, S-ketamine, Pediatrics, Caudal Block, Hypospadias

Intervention / Treatment
-----------------
* Drug: S-ketamine & Ropivacaine
* Drug: Ropivacaine


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: informed parent consent, ASA I or II children, between 3months and 18 years of age,and weighing <28kg, scheduled for elective hypospadias surgery with general anesthesia will be recruited. Exclusion Criteria: Patients who have congenital abnormalities of lower spine and meninges. Patients with hypersensitivity to any local anesthetics Children with coagulation disorders Presence of Infections at puncture sites Preexisting neurological disease Refusal to consent by parent/guardian

Ages Eligible for Study
-----------------
Minimum Age: 3 Months
Maximum Age: 18 Years

Sexes Eligible for Study
-----------------
Male

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group E<br>the children are given a mixture of 0.2%ropivacaine 0.7 ml／kg and preservative-free S-ketamine 0.5 mg/kg for caudal analgesia. | Drug: S-ketamine & Ropivacaine<br>* The experiment group (Group E) will receive a mixture of ropivacaine 0.2% 0.7 ml／kg and preservative-free S-ketamine 0.5 mg/kg caudally for postoperative analgesia.<br>|
| Active Comparator: Group C<br>The children are given 0.2%ropivacaine 0.7 ml／kg and saline of equal volume caudally. | Drug: Ropivacaine<br>* The experiment group (Group C) will receive ropivacaine 0.2% 0.7 ml／kg plain and equial volume saline caudally for postoperative analgesia.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| duration of caudal analgesia | Duration of analgesia is defined as the time from caudal injection to the first need for systemic analgesia. | 48 hours after the caudal injection | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| morphine consumption | The Face, Legs, Activity, Cry, and Consolability (FLACC) scale at 1 hour (h), 3h,6h,12h,24h,48h or the time when children complain of pain after surgery. A score of more than 3 points is taken as an indication of inadequate analgesia and morphine 15ug/kg was administered . | 48 hours after caudal block | 
| FLACC score | The Face, Legs, Activity, Cry, and Consolability (FLACC) scale | 48 hours after the caudal block | 
| complication | the incidence of residual motor block, urinary retention, paraesthesia; the incidence of respiratory depression ,vomiting ,nystagmus ,pruritus，odd behavior;.the sedation scores etc. | 48 hours after the caudal block |