Effect of N2O on Intraocular Pressure in Healthy Volunteers
试验速览
- 阶段
- 4 期
- 状态
- 已完成
- 入组人数
- 20
- 试验地点
- 1
- 主要终点
- Change in Intraocular Pressure During Nitrous Oxide Sedation
研究概览
简要总结
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.
详细描述
An initial pre-anesthetic evaluation and physical examination will be performed by an attending anesthesiologist, and an eye exam will be performed by an attending ophthalmologist to determine suitability for inclusion according to the above criteria. Ideally the eye exam will take place immediately prior to conduction of the study. However, logistical restraints may require that the eye exam take place at a separate time/date prior to conduction of the study. IOPs will be measured by the attending ophthalmologist (B.E.) who will be blinded to the actual readings of the Tonopen by means of a small screen, and a single trained observer (E.F.) will record observations from the Tonopen. The nitrous oxide sedation will be managed by the attending anesthesiologist (K.L.). All patients will be monitored throughout using standardized monitoring (continuous EKG, non-invasive BP, and continuous pulse oximetry).
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Diagnostic
- 盲法
- Single (Investigator)
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •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)
排除标准
- •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
研究组 & 干预措施
Nitrous oxide administration
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.
干预措施: Nitrous oxide (Drug)
结局指标
主要结局
Change in Intraocular Pressure During Nitrous Oxide Sedation
时间窗: Before, during and after administration of nitrous oxide (45 minutes total)
次要结局
未报告次要终点
研究者
Kirk Lalwani
Associate Professor, Anesthesiology and Pediatrics
Oregon Health and Science University