The Effect of Local Anesthetic and Clonidine on the Cutaneous Silent Period During Spinal Anesthesia

The Effect of Local Anesthetic and Clonidine on the Cutaneous Silent Period During and After Spinal Anesthesia

The cutaneous silent period is a non-invasive technique that gives insight into the function of thin A delta fibers and as such can be a complement to conventional electrophysiological methods used to study the peripheral nerves. Clonidine is a selective partial agonist of the alpha-2 receptors which, added intrathecally to levobupivacaine, enhances the effect of a local anesthetic, prolongs sensory and motor block during local anesthesia and extends the length of post-operative analgesia. It is believed that clonidine achieves this effect by activating the postsynaptic alpha-2 receptors in the gelatine substance of the spinal cord and blocking the conduction of A-delta and C fibers. The aim of the study is to examine functional changes of Aδ - fibers during the application of spinal anesthesia by measuring the cutaneous slinet period and compare the effect of intrathecal administration of a combination of local anesthetic and clonidine in the quiet skin period in relation to the application of local anesthetic only.

Study Overview

• Status: Active, not recruiting
• Conditions: Inguinal Hernia; Spinal Anesthesia
• Intervention / Treatment: Drug: levobupivacaine; Drug: clonidine

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Phase 4

Contacts and Locations

Study Locations

• Croatia
  • Zagreb, Croatia, 10000
    • Clinical Hospital Dubrava

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

ASA one and two status BMI 18,5 to 24

Exclusion Criteria:

Coagulation disorders Polyneuropathy Diabetes mellitus Alcoholism Systemic inflammatory and malignant diseases Stroke

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 0.5% levobupivacaine with 0.015% clonidine; 0.5% levobupivacaine 15 mg with 0.015% clonidine 50 mcg and 40% glucose 0.5 ml will be preformed as subarachnoid block	Drug: levobupivacaine; Comparing: 0.5% levobupivacaine 15 milligrams (mg) , 0.015% clonidine 50 micrograms (mcg) and 40% glucose 0.5 milliliters (ml) with 0.5 levobupivacaine 15 mg , 0.9% saline 0.33 ml and 40% glucose 0.5 ml; Other Names: chirocaine; Drug: clonidine; Comparing: 0.5% levobupivacaine 15 mg , 0.015% clonidine 50 mcg and 40% glucose 0.5 ml with 0.5 levobupivacaine 15 mg , 0.9% saline 0.33 ml and 40% glucose 0.5 ml; Other Names: catapressan
Active Comparator: 0.5% levobupivacaine with 0.9% saline; 0.5% levobupivacaine 15 mg with 0.33 ml of 0.9% saline and 40% glucose 0.5 ml will be preformed as subarachnoid block	Drug: levobupivacaine; Comparing: 0.5% levobupivacaine 15 milligrams (mg) , 0.015% clonidine 50 micrograms (mcg) and 40% glucose 0.5 milliliters (ml) with 0.5 levobupivacaine 15 mg , 0.9% saline 0.33 ml and 40% glucose 0.5 ml; Other Names: chirocaine; Drug: clonidine; Comparing: 0.5% levobupivacaine 15 mg , 0.015% clonidine 50 mcg and 40% glucose 0.5 ml with 0.5 levobupivacaine 15 mg , 0.9% saline 0.33 ml and 40% glucose 0.5 ml; Other Names: catapressan

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
4 Item Duration of Latency and duration of the cutaneous silent period	Duration of latency and duration of the cutaneous silent (msec) period before subarahnoid block, after regression of motor block, sixth hour of intrathecal administration, 24 hours after intrathecal administration	24 hours perioperative

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of motor block	The duration of motor block and its regression will be monitored by Bromage scale:0- Bromage patient can perform movements in the hip, knee and foot. Bromage 1-patient can not perform movements in the hip, but can flexes the knee and move the foot, Bromage 2- patient can not perform movements in the hip and knee, but can move a foot. Bromage 3- patient can not perform movements in the hip, knee nor move the foot. The time of intrathecal levobupivacaine solution or levobupivacaine and clonidine solution is considered to be time zero.	24 hours perioperative
Duration of sensory block	The time needed for the regression of sensory block in two dermatome will be measured; the time (min) required for a regression in the S1 dermatome, the time required to restore motor functions in Bromage 0 and the duration of analgesia(min).	24 hours perioperative

Collaborators and Investigators

• Sponsor: University Hospital Dubrava

Publications and helpful links

General Publications

• Inghilleri M, Cruccu G, Argenta M, Polidori L, Manfredi M. Silent period in upper limb muscles after noxious cutaneous stimulation in man. Electroencephalogr Clin Neurophysiol. 1997 Apr;105(2):109-15. doi: 10.1016/s0924-980x(97)96579-6.
• Mota IA, Fernandes JB, Cardoso MN, Sala-Blanch X, Kofler M, Valls-Sole J. Temporal profile of the effects of regional anesthesia on the cutaneous reflexes of foot muscles. Exp Brain Res. 2015 Sep;233(9):2587-96. doi: 10.1007/s00221-015-4329-2. Epub 2015 May 30.
• Uncini A, Kujirai T, Gluck B, Pullman S. Silent period induced by cutaneous stimulation. Electroencephalogr Clin Neurophysiol. 1991 Oct;81(5):344-52. doi: 10.1016/0168-5597(91)90023-q.

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2017
• Primary Completion (Estimated): September 1, 2027
• Study Completion (Estimated): October 1, 2028

Study Registration Dates

• First Submitted: April 11, 2017
• First Submitted That Met QC Criteria: April 19, 2017
• First Posted (Actual): April 20, 2017

Study Record Updates

• Last Update Posted (Actual): May 4, 2026
• Last Update Submitted That Met QC Criteria: April 28, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: clonidine; levobupivacaine; nerve fibers
• Additional Relevant MeSH Terms: Pathological Conditions, Anatomical; Hernia; Hernia, Abdominal; Pathological Conditions, Signs and Symptoms; Hernia, Inguinal; Organic Chemicals; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Azoles; Imidazoles; Anilides; Amides; Aniline Compounds; Amines; Imidazolines; Bupivacaine; Levobupivacaine; Clonidine
• Other Study ID Numbers: 070219812014

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No