Study on the Effects of Intravenous Dexmedetomidine on Pain in Patients Undergoing Elective Spinal Surgery

Study Overview
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Brief Summary
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This is a randomized, prospective, double-blind , placebo-controlled trial examining the effects of intraoperative dexmedetomidine infusion on pain in patients undergoing lumbar spinal fusion surgery. One hundred ten subjects (55 in each arm) will be enrolled. Subjects, over the age of 18, undergoing lumbar spinal fusion will be considered eligible for enrollment. Subjects will receive either intraoperative dexmedetomidine or placebo of normal saline infusion. They will be followed for approximately six weeks postoperatively.

Official Title
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Randomized, Double-blind, Placebo-controlled Study on the Effects of Intravenous Dexmedetomidine on Pain in Patients Undergoing Elective Spinal Surgery

Conditions
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Chronic Pain

Intervention / Treatment
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* Drug: Dexmedetomidine
* Other: Placebo Saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults who will undergo lumbar spinal fusion, including surgeries extending into thoracic and sacral segments Subject is non-lactating and is either: Not of childbearing potential Of childbearing potential but is not pregnant at time of surgery as determined by pre-surgical pregnancy testing Subject is ASA physical status 1, 2, or 3. Exclusion Criteria: Subject is pregnant or breastfeeding Any subject whom the investigators deem unable to complete any/all research related tasks Subjects who are cognitively impaired (by history) Subject requires antipsychotic medications Subject has received treatment with alpha-2 agonists or antagonists within 2 weeks prior to surgery Subject has known allergy to dexmedetomidine Subjects with impaired renal or hepatic function Subjects with advanced heart block Subjects with severe ventricular dysfunction

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: IV dexmedetomidine<br>Dexmedetomidine is an alpha-2-adrenergic agonist. It is commonly used for sedation and as an adjunct to general anesthetics. | Drug: Dexmedetomidine<br>* The drug will be administered with a loading dose of 0.5 mcg/kg given over 20 min followed by an infusion at 0.6 mcg/kg/hr. The infusion will be stopped during closure of the fascia.<br>|
| Placebo Comparator: Placebo<br>saline placebo | Other: Placebo Saline<br>* Placebo will be administered with a loading dose of 0.5 mcg/kg given over 20 min followed by an infusion at 0.6 mcg/kg/hr. The infusion will be stopped during closure of the fascia.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Morphine Equivalents Used During the First 48 Hours Post-Surgery | Amount of morphine administered during the 48 hours following surgery. | Up to 48 Hours Post-Surgery (Day 2) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean Numeric Pain Rating Scale (NRS) Scores During the First 48 Hours Post-Surgery | The NPRS is a self-assessment of pain. Participants select a number between 0 and 10 that fits best to their pain intensity, where 0 represents 'no pain at all' and 10 represents 'the worst pain ever possible.' | 48 Hours Post-Surgery (Day 2) | 
| Numeric Pain Rating Scale (NPRS) Score at 6 Weeks Post-Surgery | The NPRS is a self-assessment of pain. Participants select a number between 0 and 10 that fits best to their pain intensity, where 0 represents 'no pain at all' and 10 represents 'the worst pain ever possible.' | Week 6 | 
| Morphine Equivalents Used at 6 Weeks Post-Surgery | Amount of morphine administered during the 6 weeks following surgery. | Up to Week 6 | 
| Number of Participants Requiring Pressor Use During Intraoperative Period | The intraoperative period begins when the patient is transferred to the operating room table and ends with the transfer of a patient to the Post Anesthesia Care Unit (PACU). | From beginning up to end of surgery (Day 0 - typically 1 to 3 hours) | 
| Number of Participants Requiring Pressor Use During First 48-Hours Post-Surgery |  | Up to 48 Hours Post-Surgery (Day 2) | 
| Length of PACU Stay |  | From PACU admission up to end of PACU stay (Day 0 - typically 1 to 3 hours) | 
| Length of Hospital Stay |  | From admission up to discharge (Up to 6 Weeks) | 
| Mean Quality of Recovery After Anesthesia (QoR-15) Scores During the First 48 Hours Post-Surgery | The QoR-15 is a 15-item self measurement of patients' overall satisfaction with postoperative recovery. Items are ranked on a Likert scale of 0 to 10, where: 0 = none of the time [poor] and 10 = all of the time [excellent]. Higher scores indicate greater satisfaction with postoperative recovery. The total score ranges from 0 to 150; higher scores indicate greater satisfaction with postoperative recovery. | 48 Hours Post-Surgery (Day 2) | 
| Quality of Recovery After Anesthesia (QoR-15) Score at 6 Weeks Post-Surgery | The QoR-15 is a 15-item self measurement of patients' overall satisfaction with postoperative recovery. Items are ranked on a Likert scale of 0 to 10, where: 0 = none of the time [poor] and 10 = all of the time [excellent]. Higher scores indicate greater satisfaction with postoperative recovery. The total score ranges from 0 to 150; higher scores indicate greater satisfaction with postoperative recovery. | Week 6 | 
| Mean Short-Form McGill Pain Questionnaire (SF-MPQ) Scores During First 48 Hours Post-Surgery | The SF-MPQ is a self-assessment of pain symptoms. The questionnaire includes 15 pain descriptor items that are ranked on a Likert scale from 0 (none) to 3 (severe); one Visual Analogue Scale (VAS) item on which participants rank pain on a 10 cm VAS; and one Present Pain Intensity item on which participants rank their present pain on a Likert scale from 0 (no pain) to 5 (excruciating). The total score is the sum of responses and ranges from 0-60; lower scores indicate less pain. The SF-MPQ is administered on postoperative days 1 and 2. | 48 Hours Post-Surgery (Day 2) | 
| Short-Form McGill Pain Questionnaire (SF-MPQ) Scores at 6 Weeks Post-Surgery | The SF-MPQ is a self-assessment of pain symptoms. The questionnaire includes 15 pain descriptor items that are ranked on a Likert scale from 0 (none) to 3 (severe); one Visual Analogue Scale item on which participants rank pain on a 10 cm VAS; and one Present Pain Intensity item on which participants rank their present pain on a Likert scale from 0 (no pain) to 5 (excruciating). The total score is the sum of responses and ranges from 0-60; lower scores indicate less pain. | Week 6 |