Optimal Single Dose Intrathecal Dexmedetomidine for Postoperative Analgesia

Optimal Single-dose Intrathecal Dexmedetomidine for Postoperative Analgesia After Lower Limb Surgery

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.

Study Overview

• Status: Unknown
• Conditions: Lower Limb Surgery
• Intervention / Treatment: Drug: Intrathecal dexmedetomidine

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.

• Study Type: Interventional
• Enrollment (Anticipated): 15
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Samah Elkenany, MD; Phone Number: 00201002262557; Email: sk_20022000@yahoo.com

Study Locations

• Egypt
  • DK
    • Mansoura, DK, Egypt, 050
      • Recruiting
      • Mansoura University
      • Contact: Samah Elkenany, MD; Phone Number: 00201002262557; Email: sk_20022000@yahoo.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 63 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Intrathecal dexmedetomidine; Up-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	Drug: Intrathecal dexmedetomidine; 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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of analgesia	The duration of analgesia, defined as the time from administering of intrathecal study solution (T0) to the time for the first rescue analgesic request	For 13 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative pain score	Using visual analog scale	For 24 hours after surgery
Onset of sensory blockade	Onset of sensory block time defined as the time elapsed from T0 to achieve the adequate sensory level for the planned surgery.	For 1 hour after initiaion of spinal anesthesia
Onset of motor blockade	Onset of motor block time defined as the time elapsed from T0 to achieve the Bromage scale of 3	For 2 hours after initiation of spinal anesthesia
Highest dermatome level of sensory blockade	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	For 4 hours after initiation of spinal anesthesia
Time to motor regression	Time to motor regression to a Bromage scale of 2	For 6 hours after initiation of spinal anesthesia
Sedation score	Sedation scores will be assessed using a sedation scale (awake and alert= 0; quietly awake= 1; asleep but easily roused= 2; deep sleep= 3).	For 24 hours after initiation of spinal anesthesia
Postoperative nausea and vomiting	The degree of nausea and vomiting. Nausea will be measured using a numerical rating system (none= 0; mild= 1; moderate= 2; severe= 3)	For 24 hours after initiation of spinal anesthesia
Cumulative tramadol consumption		For 24 hours after surgery
Intraoperative bradycardia		For 4 hours after initiation of spinal anesthesia
Intraoperative use of ephedrine		For 4 hours after initiation of spinal anesthesia
Intraoperative use of atropine		For 4 hours after initiation of spinal anesthesia
Intraoperative use of supplemental fentanyl		For 4 hours after initiation of spinal anesthesia
Intraoperative use of midazolam		For 4 hours after initiation of spinal anesthesia

Collaborators and Investigators

• Sponsor: Mansoura University

Study record dates

Study Major Dates

• Study Start: January 1, 2016
• Primary Completion (Anticipated): May 1, 2017
• Study Completion (Anticipated): June 1, 2017

Study Registration Dates

• First Submitted: January 16, 2016
• First Submitted That Met QC Criteria: January 16, 2016
• First Posted (Estimate): January 21, 2016

Study Record Updates

• Last Update Posted (Actual): February 27, 2017
• Last Update Submitted That Met QC Criteria: February 24, 2017
• Last Verified: February 1, 2017

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Analgesics, Non-Narcotic; Adrenergic alpha-2 Receptor Agonists; Adrenergic alpha-Agonists; Adrenergic Agonists; Hypnotics and Sedatives; Dexmedetomidine
• Other Study ID Numbers: R ∕ 16.01.15

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided