Nitrous Oxide - Sevoflurane-Remifentanil Interaction

Nitrous Oxide - Sevoflurane-Remifentanil Interaction: Multiple Response Surfaces, Validation of Calibration Stimuli, Validation of the Intraoperative Isobole Concept and Investigating Remifentanil Induced Opioid Tolerance.

patients are allocated to one of the two study groups.

In both groups a mixture of 60% nitrous oxide and 40% oxygen is administered through a face mask. In the first group the patient receives a constant concentration of sevoflurane. In this group the remifentanil concentration will be injected via an intravenous line in a step up protocol. In the second group remifentanil is injected in a fixed rate and sevoflurane is administered in a step up concentration.

During the study, at predefined times, we will assess different levels of sedation (OAA/S score) and the reaction on tetanic stimulation of the ulnar nerve, insertion of a laryngeal mask airway and laryngoscopy. In addition heart rate, SpO2 and capnography will be recorded continuously and non invasive bloodpressure will be recorded using a 1 minute interval time. Spectral entropy and BIS derived from the frontal EEG will be used to monitor clinical cerebral drug effect.

The null hypothesis is that remifentanil lowers the concentration of sevoflurane dissolved in a mixture of 60% nitrous oxide and 40% oxygen to (1) tolerate a specific stimulation and to (2) obtain a certain electroencephalographic parameter value and vice versa. Additionally the results of this study will be compared with a former interaction study of the same study group that did not involve nitrous oxide, in order to depict the shift in the response surface evoked by nitrous oxide.

Study Overview

• Status: Terminated
• Conditions: ASA Class I/II Patients Scheduled for Surgery Under General Anesthesia
• Intervention / Treatment: Drug: remifentanil injected; Drug: sevoflurane in step up concentration

• Study Type: Interventional
• Enrollment (Actual): 4
• Phase: Phase 4

Contacts and Locations

Study Locations

• Belgium
  • Ghent, Belgium
    • University Hospital Ghent

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• American Society of Anesthesia class I and II patients
• aged 18-60 years
• scheduled for surgery under general anesthesia.

Exclusion Criteria:

• Weight less than 70% or more than 130% of ideal body weight
• neurological disorder
• diseases involving the cardiovascular system, pulmonary disease, gastric diseases, endocrinological diseases
• recent use of psycho-active medication, including alcohol

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: remifentanil injected; a mixture of 60% nitrous oxide and 40% oxygen is administered through a face mask. In the first group the patient receives a constant concentration of sevoflurane. In this group the remifentanil concentration will be injected via an intravenous line in a step up protocol.	Drug: remifentanil injected; mixture of 60% nitrous oxide and 40% oxygen is administered through a face mask. In the first group the patient receives a constant concentration of sevoflurane. In this group the remifentanil concentration will be injected via an intravenous line in a step up protocol.
Active Comparator: sevoflurane in step up concentration; a mixture of 60% nitrous oxide and 40% oxygen is administered through a face mask. remifentanil is injected in a fixed rate and sevoflurane is administered in a step up concentration.	Drug: sevoflurane in step up concentration; of 60% nitrous oxide and 40% oxygen is administered through a face mask.remifentanil is injected in a fixed rate and sevoflurane is administered in a step up concentration.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To investigate the pharmacodynamic interaction between nitrous oxide, sevoflurane and remifentanil	The interaction is studied on response surfaces including several clinical endpoints: the observer assessment of alertness and sedation scale, the heart rate, pulse oximetry, blood pressure, EEG and the derived parameters from it: spectral entropy and BIS	Every 12 minutes during induction and maintenance of anesthesia

Collaborators and Investigators

• Sponsor: University Hospital, Ghent
• Investigators: Principal Investigator: Hugo Vereecke, MD, PhD, University Hospital, Ghent

Publications and helpful links

Helpful Links

• website University Hospital Ghent

Study record dates

Study Major Dates

• Study Start: February 1, 2010
• Primary Completion (Actual): May 1, 2010
• Study Completion (Actual): May 1, 2010

Study Registration Dates

• First Submitted: March 19, 2010
• First Submitted That Met QC Criteria: April 12, 2010
• First Posted (Estimate): April 14, 2010

Study Record Updates

• Last Update Posted (Estimate): May 8, 2012
• Last Update Submitted That Met QC Criteria: May 7, 2012
• Last Verified: May 1, 2012

More Information

Terms related to this study

• Keywords: ASA class I/II patients, with surgery under general anesthesia
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Anesthetics, General; Anesthetics; Platelet Aggregation Inhibitors; Analgesics, Opioid; Narcotics; Anesthetics, Inhalation; Remifentanil; Sevoflurane
• Other Study ID Numbers: 2009/493