Addition of Nitrous Oxide and Its Effects on Depth of Anesthesia

Not Applicable

Completed

• Conditions: Deep Sedation; Anesthesia, General
• Interventions: Drug: Sevoflurane group; Drug: Propofol group

• Registration Number: NCT00717574
• Lead Sponsor: University of Oklahoma

Brief Summary

The study hypothesizes that adding 60% nitrous oxide to a steady state sevoflurance or propofol anesthetic will lead to a decrease in both BIS and Entropy indices during a constant level of surgical stimulus

Detailed Description

Nitrous oxide is a widely used general anesthetic pas. It is often used in addition to a second, more potent agent. BIS and Entropy are depth of anesthesia monitors in clinical use. There are conflicting reports about the usefulness of these monitors when nitrous oxide is used as a part of the anesthetic regimen. While some studies demonstrate a decrease in BIS and Entropy, this study aims to investigate the effects of adding nitrous oxide to a sevoflurane or a propofol based anesthetic on BIS and Entropy indices.

Study Timeline

• Study Start: 2008-03
• Study First Submitted: 2008-07-09
• Study First Submitted QC: 2008-07-16
• Study First Posted: 2008-07-17
• Primary Completion: 2010-10
• Study Completion: 2010-10
• Results First Submitted: 2017-04-07
• Results First Submitted QC: 2017-05-26
• Status Verified: 2017-06
• Results First Posted: 2017-06-28
• Last Update Submitted: 2017-06-29
• Last Update Posted: 2017-07-31

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 32

Inclusion Criteria

• Ages 18 to 55yrs
• ASA status less than and equal to 2

Exclusion Criteria

• Surgery on head and neck
• ASA greater than 3
• Contraindication to nitrous oxide
• Pregnant women
• History of dementia and stroke, or other organic brain disorder
• Prisoner
• Ear surgery

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Sevoflurane group	Sevoflurane group	Sevoflurane based general anesthesia
Propofol group	Propofol group	Propofol based general anesthesia

Primary Outcome Measures

Name	Time	Method
The Effect of Nitrous Oxide on Bispectral Index (BIS) and State Entropy Index (SE)	From baseline to 20 minutes after the addition of 60% nitrous oxide	We planned this study to compare the effect of adding N2O on BIS and SE during an intravenous or an inhalation anesthetic. We hypothesized that neither BIS nor SE would decrease in response to the addition of N2O to a Propofol anesthetic. We also hypothesized that neither BIS nor SE would decrease in participants under Sevoflurane anesthesia if the inspired concentration of Sevoflurane were carefully and continuously adjusted to maintain a constant end-tidal concentration during the addition and discontinuation of N2O.; BIS (0-100) and SE (0-92) are unitless, ordinal indices of anesthetic depth. Both indices are decreased when the depth of anesthesia is increased.

Trial Locations

Locations (1)

University of Oklahoma Health Sciences Center; 🇺🇸 Oklahoma City, Oklahoma, United States