Comparison of Postoperative Analgesic Effect of Intrathecal Magnesium and Fentanyl Added to Bupivacaine in Patients Undergoing Lower Limb Orthopedic Surgery

Phase 2CompletedNCT01205997

Qazvin University Of Medical Sciences90 enrolled

Overview

Magnesium has been suggested that NMDA (N-methyl D-aspartate)receptor antagonists induce preemptive analgesia when administrated before tissue injury , thus decreasing the subsequent sensation of pain. Following Ethics Committee approval and informed patients consent, Ninety patients 20-60 yr old ASA physical status I or II, scheduled for femur surgery 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 magnesium group (groupM) received bupivacaine 15mg combined with 0.5ml magnesium 10%,the fentanyl group (group F) received bupivacaine 15mg combined with0.5 ml fentanyl\[25microgram\] and the placebo group (group P) received bupivacaine 15mg 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, methadon5 mg intravenously , was to be given for post-operative pain relief as needed .

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

QUADRUPLE

Enrollment

Conditions

Interventions

FentanylDRUG

Ninety patients 20-60 yr old American Society of Anesthesiologists ( ASA) physical status I or II, scheduled for femur surgery 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 magnesium group (groupM) received bupivacaine 15mg combined with 0.5ml magnesium 10%,The fentanyl group (group F) received bupivacaine 15mg combined with0.5 ml fentanyl\[25microgram\] and The placebo group (group P) received bupivacaine 15mg combined with 0.5ml distilled water(intrathecally) for each three groups 5 minutes prior to surgery)

placebo(distilled water)DRUG

magnesium sulphateDRUG

Outcomes

Primary Outcomes

Time to first requirement of analgesic supplement

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

Time frame: time to first requirement of analgesic supplement from the time of injection intrathecal anesthetic solution

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: 12 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 between the end of injection of the intrathecal anestheticthe time and regression of two segments from the maximum block height

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

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

duration of motor block was defined the time from intrathecal injection to Bromage score0

Time frame: every 5 minuts following intrathecal injection