Influence of Sevoflurane and Propofol on Maximum Muscular Strength, Speed of Contraction and Relaxation

Study Overview
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Brief Summary
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Many drugs have an influence on neuromuscular transmission. In clinical practice, neuromuscular blocking agents are commonly used, but even in the absence of neuromuscular blocking agents, anesthetic drugs can influence neuromuscular transmission. Especially volatile anesthetic agents have a clinical impact on neuromuscular transmission, they have been shown to prolong and deepen the effect of neuromuscular blocking agents. But even in the absence of neuromuscular blocking agents, volatile anesthetics can impair neuromuscular transmission. One mechanism of action is the desensitization of the acetylcholine receptors by shifting them from a normal to a desensitized state. This effect can weaken neuromuscular transmission by reducing the margin of safety that normally exists at the neuromuscular junction, or can cause an apparent increase in the capacity of neuromuscular blocking agents to block transmission. In this study, the influence of sevoflurane and propofol on the maximum force, maximum speed of contraction and relaxation will be measured at the adductor pollicis in patients having general anesthesia without the use of neuromuscular blocking agents. Maximum force and speed of contraction and relaxation will be measured before and after anesthesia by either sevoflurane or propofol. Primary outcome is the influence of either anesthetic agent on maximum muscular force and speed of contraction - relaxation, and if this influence is greater for volatile anesthetic agents than for intravenous anesthetic agents.

Official Title
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Influence of Sevoflurane and Propofol on Maximum Muscular Strength, Speed of Contraction and Relaxation, in Humans: A Pilot Study

Conditions
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Anesthesia, General, Neuromuscular Transmission Disorders

Intervention / Treatment
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* Drug: Sevoflurane
* Drug: Propofol


Participation Criteria
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Eligibility Criteria
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Inclusion criteria Patients (male or female) from 18 - 80 years Scheduled for surgery without the use of neuromuscular blocking agents Health care insurance in Belgium Written informed consent Exclusion Criteria: Any pathology involving neuromuscular transmission Confirmed neuropathy of any origin Expected anesthesia duration < 30 min Renal insufficiency defined as a glomerular filtration rate < 40 mL/min/m2 Hepatic insufficiency defined as an increase > 1.5 * normal value of hepatic enzymes Confirmed or suspected pregnancy Language barrier Any patient which will receive unplanned neuromuscular blocking agents during surgery Any history of personal or familial suspected malignant hyperthermia

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sevoflurane arm<br>In this arm, anesthesia will be maintained by sevoflurane. | Drug: Sevoflurane<br>* Anesthesia will be maintained by sevoflurane.<br>|
| Experimental: Propofol arm<br>In this arm, anesthesia will be maintained by propofol. | Drug: Propofol<br>* Anesthesia will be maintained by propofol.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximum force at the adductor pollicis | Maximum force developed by a voluntary contraction of the adductor pollicis will be measured during isometric contraction. Maximum force developped before and after anesthesia will be compared. The difference in force (Newton) will be measured. | 3 hours | 
| Maximum speed of contraction at the adductor pollicis | Maximum speed of contraction developed by a voluntary contraction of the adductor pollicis will be measured during isometric contraction. Maximum speed of contraction developped before and after anesthesia will be compared. The difference in force (Newton/seconds) will be measured. | 3 hours | 
| Maximum speed of relaxation at the adductor pollicis | Maximum speed of relaxation developed by a voluntary contraction of the adductor pollicis will be measured during isometric contraction. Maximum speed of relaxation developped before and after anesthesia will be compared. The difference in force (Newton/seconds) will be measured. | 3 hours |