Does Perineural Dexmedetomidine Prolong the Duration of an Adductor Canal Block When Controlling for a Systemic Effect? - A Randomised Paired Trial in Healthy Volunteers.
Overview
- Phase
- Phase 2
- Intervention
- Dexmedetomidine
- Conditions
- Healthy
- Sponsor
- Zealand University Hospital
- Enrollment
- 21
- Locations
- 1
- Primary Endpoint
- Difference in duration of sensory block between dexmedetomidine and placebo assessed as cold sensation with an alcohol swab
- Status
- Completed
- Last Updated
- 10 years ago
Overview
Brief Summary
Brief Summary: The aim of this trial is to investigate if dexmedetomidine prolongs the duration of an adductor canal block. By using healthy volunteers the investigators can perform a bilateral adductor canal block and thereby control for a systemic effect to clarify if the effect is actually peripheral or systemic. The investigators hypothesis is that dexmedetomidine as an adjunct to a local anaesthetic prolongs the duration of a peripheral nerve block by a peripheral mechanism.
Detailed Description
Background: Efficient pain management promoting mobilization and convalescence is essential in an ideal perioperative course. Regional nerve blocks are a central element in postoperative regimes for many patients and it is therefore important that these nerve blocks are both long lasting and efficient. This trial will investigate whether it is possible to optimize the postoperative pain management when adding dexmedetomidine to the local anaesthetic ropivacaine in peripheral nerve blocks. The prolonging effect of using dexmedetomidine as adjunct in peripheral nerve blocks have been investigated in several studies. However, it remains uncertain whether the effect is mediated by a systemic-, a peripheral- or a combined systemic/peripheral mechanism. In this trial the adjuvating effect of dexmedetomidine will be investigated using the adductor canal block. This is a nerve block that besides being efficient as pain treatment after knee surgery, is primarily sensory, and therefore augments mobilization after total knee arthroplasty. Method: On the trial day the volunteers will receive bilateral adductor canal blocks. In one thigh they will receive the local anaesthetic ropivacaine 20ml 5mg/ml and placebo (saline) and in the other thigh ropivacaine 20ml 5mg/ml and dexmedetomidine 100μg. The allocation is blinded to volunteer and investigator. The duration of the nerve block will be measured by five different tests: Temperature test, Pinprick, Pain during tonic heat stimulation, Warmth detection threshold and pain detection threshold. All tests are validated within pain research.
Investigators
Jakob Hessel Andersen
Anesthesiologist, Staff Specialist
Zealand University Hospital
Eligibility Criteria
Inclusion Criteria
- •American Society of Anesthesiologists class 1
- •Body Mass Index 18-30
Exclusion Criteria
- •Allergy to study medication
- •Earlier trauma or surgery to lower limb
- •Diabetes Mellitus
- •Alcohol or drug abuse
- •Daily intake of opioids or steroids last 4 weeks
- •Daily intake of any analgesics last 48 hours Heart block Sick sinus node.
Arms & Interventions
Ropivacaine + Dexmedetomidine
Adductor Canal Block 20 ml Ropivacaine 5mg/ml + 1 ml Dexmedetomidine 100ug/ml
Intervention: Dexmedetomidine
Ropivacaine + Dexmedetomidine
Adductor Canal Block 20 ml Ropivacaine 5mg/ml + 1 ml Dexmedetomidine 100ug/ml
Intervention: Ropivacaine
Ropivacaine + Placebo
Adductor Canal Block 20 ml Ropivacaine 5mg/ml + 1 ml Saline
Intervention: Ropivacaine
Ropivacaine + Placebo
Adductor Canal Block 20 ml Ropivacaine 5mg/ml + 1 ml Saline
Intervention: Isotonic Saline
Outcomes
Primary Outcomes
Difference in duration of sensory block between dexmedetomidine and placebo assessed as cold sensation with an alcohol swab
Time Frame: 0-36 hours
Duration is defined as time from block performance until recovery of cold sensation to an alcohol swab, assessed every hour post-block (and every half hour when pain scores during the tonic heat stimulation test is above 0) Time for sleep will be provided.
Secondary Outcomes
- Difference between dexmedetomidine and placebo in the duration of a sensory block assessed by pin-prick(0-36 hours)
- Difference between dexmedetomidine and placebo in the duration of a sensory block assessed as maximum pain during a tonic heat stimulation test(0-36 hours)
- Difference between dexmedetomidine and placebo in the duration of a sensory block assessed as warmth detection threshold(0-36 hours)
- Difference between dexmedetomidine and placebo in the duration of a sensory block assessed as heat pain detection threshold(0-36 hours)
- Difference in maximum pain scores between dexmedetomidine and placebo during block and after recovery of normal sensation.(0-36 hours)