Test of Chamber Pressure to Divers and Chamber Attendants: A Blinded Trial to Investigate if "Pressure-familiar" Individuals Can Determine Pressure
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 42
- 试验地点
- 2
- 主要终点
- Participants Indicating "I do Not Know" on Depth Questionnaire.
研究概览
简要总结
SCUBA divers and chamber inside attendants will undergo a brief hyperbaric chamber excursion and will be asked to what chamber pressure they were compressed and what gas they breathed.
详细描述
In clinical trials evaluating hyperbaric oxygen, blinding can be challenging. Options for participant blinding include offering regular air at a lower pressure than the hyperbaric oxygen intervention, or compressing all participants to the same pressure but providing different gas mixes to the active and sham arms.
In some trials of hyperbaric oxygen for brain injury, investigators offer a sham chamber session (regular air at 1.2 atmospheres absolute [atm abs]) compared to the active intervention, hyperbaric oxygen (100% oxygen at 1.5 atm abs). It is unknown whether individuals familiar with pressure changes, such as divers and hyperbaric chamber inside attendants, could discern the difference between these pressures and thereby become unblinded to study allocation.
In this study, 80 experienced divers and chamber inside attendants will be enrolled and randomly assigned to one of four possible chamber pressures and one of two breathing gases. After a brief hyperbaric chamber excursion, they will be asked to what chamber pressure they were compressed and what gas they breathed. If participants can accurately report chamber pressure or breathing gas, pressure-familiar individuals should be excluded from blinded clinical trials of hyperbaric oxygen.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Single Group
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Adult, age 18 - 65 years
- •Completion of medical history questionnaire without concerns identified for exposure to increased pressure
- •Familiarity with atmospheric pressure change:
- •Experienced and active hyperbaric chamber inside attendant: more than 50 hyperbaric compressions, with more than 4 have been in the last 4 months; or
- •Experienced and active SCUBA diver: more than 20 lifetime compressed gas open water (not swimming pool) dives, with more than 10 in the last 12 months
- •Able to equalize middle ear pressure easily
排除标准
- •Pregnancy
- •Known risk for barotrauma, as identified on the medical history questionnaire, such as:
- •Recent (within 12 months) inner ear or sinus surgery
- •Spontaneous pneumothorax
- •Pulmonary cysts
- •Emphysema
- •Bullous lung disease
- •Chronic obstructive pulmonary disease needing chronic active therapy
- •Inability to tolerate chamber confinement or pressure
- •Presence of heart failure
- •Presence of any implanted electrical device, except hyperbaric-approved pacemakers
- •Presence of middle-ear tympanostomy tubes
研究组 & 干预措施
Sea Level Equivalent 1.2 atm abs (air)
Sham Chamber Session
Sea Level Equivalent 1.2 atm abs (2.6 psig) breathing regular air 20-chamber excursion
干预措施: Sham Chamber Session (Drug)
Sea Level Equivalent 1.5 atm abs (O2)
Hyperbaric Oxygen (1.5 atm abs)
Sea Level Equivalent 1.5 atm abs (6.2 psig) breathing 100% oxygen 20-minute chamber excursion
干预措施: Hyperbaric Oxygen (1.5 atm abs) (Drug)
Altitude Equivalent 1.2 atm abs (air)
Sham Chamber Session
Altitude Equivalent 1.2 atm abs (5.1 psig) breathing regular air 20-minute chamber excursion
干预措施: Sham Chamber Session (Drug)
Altitude Equivalent 1.5 atm abs (O2)
Hyperbaric Oxygen (1.5 atm abs)
Altitude Equivalent 1.5 atm abs (9.6 psig) breathing 100% oxygen 20-minute chamber excursion
干预措施: Hyperbaric Oxygen (1.5 atm abs) (Drug)
结局指标
主要结局
Participants Indicating "I do Not Know" on Depth Questionnaire.
时间窗: Within 15 minutes of chamber excursion
Participants indicating "I do not know" on depth questionnaire instead of providing a free response guess.
Participant Perception of Depth
时间窗: Within 15 minutes of chamber excursion
Mean depth perception for participants providing a free response.
Participant Perception of Breathing Gas
时间窗: Within 15 minutes of chamber excursion
Percent of participants in each arm guessing that their breathing gas was 100% oxygen.
次要结局
未报告次要终点