Effect of Nitrous Oxide (N2O) on Intraocular Pressure in Healthy Volunteers

NCT00967694 | Completed Phase 4 Results

• 1 other identifier: IRB00005402
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to learn if breathing nitrous oxide (also known as "laughing gas") changes the pressure in a person's eyes. Some patients who need regular eye exams to measure their eye pressure often need to be put to sleep with medicine in order to complete the eye exam. Some of these medicines are known to cause changes in a person's eye pressure. Because of this, such medicines are avoided if the eye doctor needs to measure the patient's eye pressure. One medicine that is frequently used to put patients to sleep is nitrous oxide. No one really knows what effect nitrous oxide might have on a persons' eye pressure. The investigators are interested to see if nitrous oxide causes an increase, decrease, or no change in eye pressure. The investigators also want to investigate if there is a difference in the effects of nitrous oxide on eye pressure between males and females. Understanding these effects of nitrous oxide is important because during such eye exams, the eye doctor uses the pressure measurements to make important decisions about treatment and surgery options for the patient. The investigators hypothesize that the use of inhaled nitrous oxide (N2O) will result in a decrease in IOP in healthy volunteers. The investigators aim to determine the magnitude and duration of change, if any, in IOP caused by inhalation of N2O, and to assess if the gender of the patient has a role in this effect.

Conditions

Glaucoma; Sedation

Keywords

Glaucoma; Nitrous oxide

Outcome Measures

Primary Outcomes (1)

• Change in Intraocular Pressure During Nitrous Oxide Sedation

  Before, during and after administration of nitrous oxide (45 minutes total)

Study Arms (1)

Nitrous oxide administration

EXPERIMENTAL

All 20 healthy volunteers had their intraocular pressure (IOP) measured at baseline and then after 3, 6, 9, and 12 minutes of nitrous oxide administration, and then after 5, 10, and 15 minutes of breathing room air. There was therefore only one study arm, with each individual serving as their control for baseline and then intervention values of IOP measurement.

Drug: Nitrous oxide

Interventions

Nitrous oxide DRUG

Nitrous oxide sedation by inhalation

Also known as: N2O

Nitrous oxide administration

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Adults aged 18-40
• American Society of Anesthesiologists Physical Classification System (ASA) Status 1-2
• Nil per os (NPO) prior to study (2 hrs clear liquids, 4 hrs milk, 6 hrs light food, 8 hrs heavy/greasy food)

You may not qualify if:

• Lack of volunteer consent
• Pregnancy
• History of features suggestive of a difficult airway on pre-anesthetic evaluation and physical examination
• Active gastroesophageal reflux disease
• Active obstructive sleep apnea
• History of recent trauma
• History of pneumothorax or lung cyst
• History of Vitamin B12 deficiency
• History of recent middle ear surgery (\<3months)
• Current or recent (\<3 weeks) respiratory tract infection
• Any acute illness or exacerbation of chronic illness such as asthma, chronic lung disease etc.
• Any history of cardiac ischemia (angina), myocardial infarction, or cardiac dysrhythmia.
• Myopia greater than -3 spherical equivalents or hyperopia greater than +3 spherical equivalents
• History of eye surgery of any sort, including refractive surgery, cataracts, and vitrectomy
• History of any ocular disease or infection

Sponsors & Collaborators

• Oregon Health and Science University: lead
• Robert L. Bacon Medical Foundation: collaborator
• Research to Prevent Blindness: collaborator

Study Sites (1)

OHSU

Portland, Oregon, 97239, United States

Location

MeSH Terms

Conditions

Glaucoma

Interventions

Nitrous Oxide

Condition Hierarchy (Ancestors)

Ocular Hypertension; Eye Diseases

Intervention Hierarchy (Ancestors)

Nitrogen Oxides; Gases; Inorganic Chemicals; Nitrogen Compounds; Oxides; Oxygen Compounds

Results Point of Contact

• Title: Dr. Eric Fox
• Organization: University of Utah Department of Anesthesiology

ericbfox@yahoo.com

775-340-0219

Study Officials

• Kirk Lalwani, MD,FRCA,MCR

  Oregon Health and Science University

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: NA
• Masking: SINGLE
• Who Masked: INVESTIGATOR
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor, Anesthesiology and Pediatrics

Study Record Dates

• First Submitted: August 27, 2009
• First Posted: August 28, 2009
• Study Start: August 1, 2009
• Primary Completion: October 1, 2011
• Study Completion: October 1, 2011
• Last Updated: September 23, 2014
• Results First Posted: September 23, 2014

Record last verified: 2014-09

Locations

US (1)