Spinal or Intravenous Dexmedetomidine in Ambulatory Surgery

Study Overview
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Brief Summary
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The primary objective of this double blind randomized study is to determine the effect of dexmedetomidine on onset and duration of the sensory and motor block and on the influence on bladder function after spinal anesthesia with chloroprocaine. Our primary hypothesis is that sensory block will significantly be prolonged by dexmedetomidine administered by both the spinal and the intravenous route. The investigators do not expect a significant difference in motor block duration between intravenous or spinal administration. Secondary outcomes are micturition problems, duration of analgesia and the occurrence of side effects such as sedation and hypotension.

Detailed Description
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The study is designed as a multicenter study and randomization and inclusion of patients will be performed in three hospitals. Each hospital has its own randomisation sequence and coordinating investigator who will be responsible for appointing blinded and unblinded participators in the study. Patients scheduled for spinal anesthesia in ambulatory surgery will be randomized by sealed envelopes (computer generated sequence) into one of the following three study groups: spinal chloroprocaine 40 mg with spinal dexmedetomidine (5mcg) spinal chloroprocaine 40 mg with intravenous dexmedetomidine ( 0.5 mcg/kg) spinal chloroprocaine 40 mg alone (control group) All patients will receive the same amount of spinal solution, containing chloroprocaine 1% (4 ml) with dexmedetomidine (0.5 ml, 1 mcg/ml) or NaCl ( sodiumchloride) 0,9% (0.5 ml ) ( and 50 ml intravenous Nacl 0.9, containing dexmedetomidine (0.5 mcg/kg) or not depending on the study group. All solutions are prepared by an independent anesthesiologist and labelled as Intravenous study medication and spinal study medication. Spinal anesthesia and data registration will be done by a blinded anesthesist and/or study nurse on a data sheet designed for the study. Spinal anesthesia is performed in the lateral decubitus at L3-L4 vertebral interspace and standard monitoring for this procedure is applied. Insufficient analgesia will be treated with sufentanil increments. Hypotension and bradycardia will be treated with ephedrine and atropine. Patients will be discharged when the block is regressed, there is no sedation or nausea and nrs scores of pain are below 4. Patients will be contacted by telephone after one week to evaluate any postoperative complaints.Micturition will receive a score based on bladder volumes measured by bladder scanning and subjective complaints . This score system was used in two of our former studies (1,2) To calculate the power of this study, we used the mean L2 regression of a previous study after spinal chloroprocaine with its standard deviation (SD 20 min, mean 90 min) and compared it to a mean increase with 30 %. We calculated that we should include 7 patients in each group to obtain a power of 80%. To be sure to detect a possible difference in discharge time as well, we calculated a sample size of 48 patients for each group to detect a 30-minute difference. Statistical analysis will be done with ANOVA analysis , A kruskal-Wallis of Mann Whitney test depending on the distribution of the population and if the values are parametric or not. This will be done by spss.

Official Title
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Influence of Spinal or Intravenous Dexmedetomidine on Spinal Anesthesia With Chloroprocaine and Bladder Function in Day-case Surgery. A Double Blind Randomized Study.

Conditions
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Surgery Ambulatory

Intervention / Treatment
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* Drug: spinal dexmedetomidine 0.5 mcg
* Other: spinal chloroprocaine 40 mg
* Drug: IV dexmedetomidine 0.5 mcg/kg


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA (American Society of Anesthesiologists) class 1 & 2, undergoing day-case knee arthroscopy Exclusion Criteria: micturition problems, neurological history or previous lower abdominal surgery with an abnormal micturition

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: A chloro<br>spinal chloroprocaine 40 mg | Other: spinal chloroprocaine 40 mg<br>* spinal anesthesia with chloroprocaine 40 mg<br>* Other names: ampres;|
| Experimental: B chloro+ spin dexdor<br>Spinal chloroprocaine 40 mg spinal dexmedetomidine 0.5 mcg | Drug: spinal dexmedetomidine 0.5 mcg<br>* Administration of dexmedetomidine 0.5 mcg<br>* Other names: dexdor;Other: spinal chloroprocaine 40 mg<br>* spinal anesthesia with chloroprocaine 40 mg<br>* Other names: ampres;|
| Experimental: C chloro + IV dexdor<br>Spinal chloroprocaine 40 mg IV dexmedetomidine 0.5 mcg/kg | Other: spinal chloroprocaine 40 mg<br>* spinal anesthesia with chloroprocaine 40 mg<br>* Other names: ampres;Drug: IV dexmedetomidine 0.5 mcg/kg<br>* intravenous administration of dexmedetomidine 0.5 mcg/kg<br>* Other names: dexdor;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| sensory block regression L2 dermatome (minutes) (Time from injection until First time registration of loss of cold sensation) | Time from injection until First time registration of loss of cold sensation at the L2 dermatome during block regression. Loss of cold sensation will be regularly assessed from spinal injection until total regression of the sensory block | up to 360 minutes | 
| Motor block regression (minutes) (time from injection until achievement of active knee movement) | time from injection until achievement of active knee movement during block regression. Motor block will be assessed at regular intervals from spinal injection untill total regression of the motor block | up to 240 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| discharge time (minutes) | time from spinal injection until achievement of discharge criteria | up to 240 minutes | 
| time to micturition ( minutes) | time from injection until first voiding | up to 240 minutes | 
| blood pressure drop | percentage of drop blood pressure compared to base line ( measured before spinal injection) . Blood pressure will be measured at regular intervals from just prior to spinal injection until discharge | up to 240 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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spinal or intravenous dexmedetomidine