Evaluation of the Analgesic Effect of Midazolam and Ketamine as an Additive to Intrathecal Bupivacaine in Patients Undergoing Cesarean Section

Qazvin University Of Medical Sciences90 enrolled

Overview

Objective :To compare the analgesic effect of intrathecal midazolam and ketamine 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 ketamine group (groupK) received bupivacaine 10mg combined with 0.1 mg/kg ketamine preservative free ,the midazolam group (group M) received bupivacaine 10mg combined with0.02 mg/ kg midazolam 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 patients were randomly allocated to one of three groups of 30 each. The ketamine group (groupK) received bupivacaine 10mg combined with 0.1 mg/kg ketamine preservative free ,the midazolam group (group M) received bupivacaine 10mg combined with0.02 mg/ kg midazolam and the placebo group (group P) received bupivacaine 10mg combined with 0.5ml distilled water intrathecally .

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

Outcomes

Primary Outcomes

Time to first requirement of analgesic supplement

analgesic administration was initiated by patient request(verbal rating scale\[ VRS\]\>4)

Time frame: 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

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)

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

Secondary Outcomes

Sensory block onset time will be assessed by a pinprick test

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

Time frame: sensory block will be assessed by pinprick test every 10 seconds following intrathecal injection

duration of sensory block will be assessed by a pinprick test

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

Time frame: sensory block will be assessed by pinprick test every 5 minuts following intrathecal injection

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

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

Time frame: every10 seconds following intrathecal injection