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

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

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.

The clonidine group (groupC) received bupivacaine 10mg combined with 75 microgram clonidine preservative free intrathecally

The fentanyl group (groupF) received bupivacaine 10mg combined with 25 microgram clonidine preservative free intrathecally

The placebo group (group P) received bupivacaine 10mg combined with 0.5ml distilled water intrathecally .

The placebo group (group P) received bupivacaine 10mg combined with 0.5ml distilled water intrathecally .

The clonidine group (group C) received bupivacaine 10mg combined with 75 microgram clonidine intrathecally .

The Fentanyl group (group F) received bupivacaine 10mg combined with 25 microgram fentanyl intrathecally .

participants will be followed for the duration of 24 hours after intratechal injection (Time from the injection of intrathecal anesthetic solution to first requirement of analgesic supplement will be recorded.

postoperative analgesic requirements will be assessed by verbal rating scale (VRS) from 0 to 10 (0no pain, 10maximum imaginable pain).Each administration was initiated by patient request( VRS>4)

24 hours postoperative(Time from the injection of intrathecal anesthetic solution to 24 hours postoperative)

The onset of sensory block was defined as the time between the end of injection of the intrathecal anesthetic and the absence of pain at the T10 dermatome

The duration of sensory block was defined as the time for regression from the maximum block height sensory block to T10 dermatom will be assessed by pinprick test every 5 minuts following intrathecal injection

The onset of motor block was defined as the time between the end of injection of the intrathecal anesthetic to Bromage block 1

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. -

Khezri MB, Rezaei M, Delkhosh Reihany M, Haji Seid Javadi E. Comparison of postoperative analgesic effect of intrathecal clonidine and fentanyl added to bupivacaine in patients undergoing cesarean section: a prospective randomized double-blind study. Pain Res Treat. 2014;2014:513628. doi: 10.1155/2014/513628. Epub 2014 Feb 4.