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Optimal Single Dose Intrathecal Dexmedetomidine for Postoperative Analgesia

Not Applicable
Conditions
Lower Limb Surgery
Interventions
Registration Number
NCT02660658
Lead Sponsor
Mansoura University
Brief Summary

Spinal anesthesia is a commonly used technique for lower limb surgeries offering better quality of postoperative analgesia, lower incidence of side effects, and shorter post-anesthesia care unit stay than general anesthesia. However, the relatively short duration of action of the currently available local anesthetics (LAs) make these advantages short-lived.

The risk for local anesthetic toxicity (LAST) increases with the trials to use higher concentrations or volumes of intrathecal local anesthetics to increase the duration of analgesia.

Dexmedetomidine has the potential to prolong the duration of perioperative analgesia without the need for using high doses of local anesthetics and hence with decreasing the potential risk of local anesthetic, but the increased likelihood adverse effects such as short term bradycardia and prolonged duration of motor block may offset these benefits.

Detailed Description

The aim of this study is to determine the optimal single-dose of intrathecal dexmedetomidine that prolongs the analgesic duration with the least possible side effects.

With the patients in the sitting position and the use of complete aseptic technique, 25G Whitacre spinal needles will be introduced through L2-L4 interspaces and after observing free flow of the CSF, a 3ml volume including bupivacaine 12.5mg in conjunction with dexmedetomidine (3 µg) will be injected in the first case, then the patient will be turned supine.

The dose of intrathecal DEX given to the next patient will be guided by modified Dixon's up-and-down method using 1.5 mg as a step size, which assumed to be of clinical importance.

Recruitment & Eligibility

Status
UNKNOWN
Sex
All
Target Recruitment
15
Inclusion Criteria
  • American Society of Anesthesiologists physical class I to II.
  • Patients scheduled for elective lower limb surgeries.
Exclusion Criteria
  • Morbid obese patients.
  • Severe or uncompensated cardiovascular disease.
  • Significant renal disease.
  • Significant hepatic disease.
  • Pregnancy.
  • Lactating .
  • Heart block.
  • Bradyarrhythmias.
  • Receiving adrenergic receptor antagonist medications.
  • Receiving calcium channel blockers.
  • Patients with pacemakers.
  • Patients with implanted cardioverter defibrillator.
  • Allergy to the study medications.
  • Psychological disease.
  • Neurological disorders.
  • Communication barrier.
  • Mental disorders.
  • Epilepsy.
  • Drug or alcohol abuse.
  • Contraindications to spinal anaesthesia.
  • Receiving opioid analgesic medications within 24 h before the operation.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Intrathecal dexmedetomidineIntrathecal dexmedetomidineUp-down sequential allocation The dose of intrathecal DEX given to the next patient will be guided by modified Dixon's up-and-down method using 1.5 mg as a step size, which assumed to be of clinical importance
Primary Outcome Measures
NameTimeMethod
Duration of analgesiaFor 13 hours after surgery

The duration of analgesia, defined as the time from administering of intrathecal study solution (T0) to the time for the first rescue analgesic request

Secondary Outcome Measures
NameTimeMethod
Cumulative tramadol consumptionFor 24 hours after surgery
Onset of motor blockadeFor 2 hours after initiation of spinal anesthesia

Onset of motor block time defined as the time elapsed from T0 to achieve the Bromage scale of 3

Postoperative pain scoreFor 24 hours after surgery

Using visual analog scale

Onset of sensory blockadeFor 1 hour after initiaion of spinal anesthesia

Onset of sensory block time defined as the time elapsed from T0 to achieve the adequate sensory level for the planned surgery.

Highest dermatome level of sensory blockadeFor 4 hours after initiation of spinal anesthesia

The highest dermatome level of sensory blockade and the time needed to achieve this level from the time of injection as well as time to two segment sensory regression after T0 will be recorded

Time to motor regressionFor 6 hours after initiation of spinal anesthesia

Time to motor regression to a Bromage scale of 2

Sedation scoreFor 24 hours after initiation of spinal anesthesia

Sedation scores will be assessed using a sedation scale (awake and alert= 0; quietly awake= 1; asleep but easily roused= 2; deep sleep= 3).

Postoperative nausea and vomitingFor 24 hours after initiation of spinal anesthesia

The degree of nausea and vomiting. Nausea will be measured using a numerical rating system (none= 0; mild= 1; moderate= 2; severe= 3)

Intraoperative bradycardiaFor 4 hours after initiation of spinal anesthesia
Intraoperative use of supplemental fentanylFor 4 hours after initiation of spinal anesthesia
Intraoperative use of ephedrineFor 4 hours after initiation of spinal anesthesia
Intraoperative use of midazolamFor 4 hours after initiation of spinal anesthesia
Intraoperative use of atropineFor 4 hours after initiation of spinal anesthesia

Trial Locations

Locations (1)

Mansoura university

🇪🇬

Mansoura, DK, Egypt

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