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.

Status

Terminated

Phases

Phase 4

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01103193

Enrollment

Registered

2010-04-14

Start date

2010-02-28

Completion date

2010-05-31

Last updated

2012-05-08

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

ASA Class I/II Patients Scheduled for Surgery Under General Anesthesia

Keywords

ASA class I/II patients, with surgery under general anesthesia

Brief summary

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.

Interventions

DRUGremifentanil 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.

DRUGsevoflurane 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.

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

BASIC_SCIENCE

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to 60 Years

Healthy volunteers

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

Design outcomes

Primary

Measure	Time frame	Description
To investigate the pharmacodynamic interaction between nitrous oxide, sevoflurane and remifentanil	Every 12 minutes during induction and maintenance of anesthesia	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

Countries

Belgium

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026