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

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

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

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.

Forty-four children scheduled for hypospadias randomize into 2 groups. Group S (n=22) (0.2% ropivacaine 1 ml／kg and S-ketamine 0.5 mg/kg), group C(n=22)( 0.2%ropivacaine 1ml／kg and equivalent saline) intraoperative and postoperative hemodynamics will be recorded. Postoperative pain is assessed using an established 15-item Parents' Postoperative Pain Measure (PPPM) at 1h,3h,6h,12h,24h,48h, or the time when children complain of pain after surgery. A score of more than 6 points is taken as an indication of inadequate analgesia and paracetamol 15 mg/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.

The Patients allocated to study groups using computer generates random list & group assignment is sealed in sequentially numbered opaque envelopes that open after induction of anesthesia.

the children are given a mixture of 0.2%ropivacaine 1 ml／kg and preservative-free S-ketamine 0.5 mg/kg for caudal analgesia.

The experiment group (Group S) will receive a mixture of ropivacaine 0.2% 1 ml／kg and preservative-free S-ketamine 0.5 mg/kg caudally for postoperative analgesia.

The experiment group (Group C) will receive ropivacaine 0.2% 1 ml／kg plain and equial volume saline caudally for postoperative analgesia.

Duration of analgesia is defined as the time from caudal injection to the first need for systemic analgesia.

Postoperative Pain Measure (PPPM) at 1 hour (h), 3h,6h,12h,24h,48h or the time when children complain of pain after surgery. A score of more than 6 points is taken as an indication of inadequate analgesia and paracetamol 15 mg/kg was administered .

the incidence of residual motor block, urinary retention, paraesthesia; the incidence of respiratory depression ,vomiting ,nystagmus ,odd behavior;.the sedation scores etc.

Inclusion Criteria: informed parent consent, ASA I or II children, between 3months and 6 years of age, 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

Gunes Y, Secen M, Ozcengiz D, Gunduz M, Balcioglu O, Isik G. Comparison of caudal ropivacaine, ropivacaine plus ketamine and ropivacaine plus tramadol administration for postoperative analgesia in children. Paediatr Anaesth. 2004 Jul;14(7):557-63. doi: 10.1111/j.1460-9592.2004.01220.x.

De Negri P, Ivani G, Visconti C, De Vivo P. How to prolong postoperative analgesia after caudal anaesthesia with ropivacaine in children: S-ketamine versus clonidine. Paediatr Anaesth. 2001 Nov;11(6):679-83. doi: 10.1046/j.1460-9592.2001.00742.x.

Weber F, Wulf H. Caudal bupivacaine and s(+)-ketamine for postoperative analgesia in children. Paediatr Anaesth. 2003 Mar;13(3):244-8. doi: 10.1046/j.1460-9592.2003.01018.x.

Martindale SJ, Dix P, Stoddart PA. Double-blind randomized controlled trial of caudal versus intravenous S(+)-ketamine for supplementation of caudal analgesia in children. Br J Anaesth. 2004 Mar;92(3):344-7. doi: 10.1093/bja/aeh076. Epub 2004 Jan 22.

Koinig H, Marhofer P, Krenn CG, Klimscha W, Wildling E, Erlacher W, Nikolic A, Turnheim K, Semsroth M. Analgesic effects of caudal and intramuscular S(+)-ketamine in children. Anesthesiology. 2000 Oct;93(4):976-80. doi: 10.1097/00000542-200010000-00017.