Comparison of Postoperative Analgesic Effect of Intrathecal Clonidine and Fentanyl Added to Bupivacaine in Patients Undergoing Cesarean Section

Condition(s) targeted: Post Operative Pain

Intervention: distilled water (Drug); Clonidine (Drug); Fentanyl (Drug)

Phase: Phase 1/Phase 2

Status: Completed

Sponsored by: Qazvin University Of Medical Sciences

Objective :To compare the analgesic effect of intrathecal clonidine and fentanyl as an additive to bupivacaine in patients undergoing cesarean section . Methods: Following Ethics Committee approval and informed patients consent, Ninety patients 18-45 yr old ASA physical status I or II, scheduled for cesarean section under spinal anesthesia, were studied in a prospective, double-blinded, randomized way. The patients were randomly allocated to one of three groups of 30 each. The clonidine group (groupC) received bupivacaine 10mg combined with 75microgram clonidine preservative free ,the fentanyl group (group F) received bupivacaine 10mg combined with25microgram fentanyl and the placebo group (group P) received bupivacaine 10mg combined with 0. 5ml distilled water intrathecally . Time to first requirement of analgesic supplement, Sensory block onset time, maximum sensory level , onset of motor block, duration of blockade, hemodynamics variables, the incidence of hypotension, ephedrine requirements, bradycardia ,hypoxemia [Saturation of peripheral oxygen (SpO2)<90], postoperative analgesic requirements and Adverse events, such as sedation, dizziness , Pruritus and postoperative nausea and vomiting were recorded. Patients were instructed preoperatively in the use of the verbal rating scale (VRS) from 0 to 10 (0no pain, 10maximum imaginable pain) for pain assessment. If the VRS exceeded four and the patient requested a supplement analgesic, diclofenac Na supp 100 mg was to be given for post-operative pain relief as needed . For breakthrough pain(VRS >4) if time of administration of diclofenac Na less than 8h,Pethidine 25 mg IV was given.

Study design: Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Prevention

Primary outcome:

Time to first requirement of analgesic supplement

Postoperative analgesic requirements

Secondary outcome:

Sensory block onset time will be assessed by a pinprick test

duration of sensory block will be assessed by a pinprick test

the onset of motor block will be assessed by the modified Bromage score

duration of motor block will be assessed by the modified Bromage score

Minimum age: 18 Years. Maximum age: 45 Years. Gender(s): Female.

Criteria:

Inclusion Criteria:

- Patients with American Society of Anesthesiologists(ASA) physical status I and II,

undergoing elective cesarean section Exclusion Criteria:

- Significant coexisting disease such as hepato-renal and cardiovascular disease

- Any contraindication to regional anesthesia such as local infection or bleeding

disorders

- Allergy to ketamine or midazolam

- Long-term opioid use or a history of chronic pain. -

Qazvin university of medical science, Qazvin 34197/59811, Iran, Islamic Republic of

Starting date: August 2011
Last updated: May 16, 2012