The Effect of Acute High Altitude Exposure on Rescuer Performance and Patient Care
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 20
- 试验地点
- 4
- 主要终点
- The effect of acute high altitude exposure on medical performance, measured by the CALM score
研究概览
简要总结
Rescue services in mountainous regions are frequently called to missions at altitudes >3000 m. Under the difficult conditions of acute exposure to altitude, the crews then have to undertake demanding medical and rescue measures. Previous studies in non-medical personnel, such as astronauts, aircraft pilots, and military helicopter pilots have found that the lack of oxygen associated with acute exposure to altitude may impair cognitive functions. No data exists on the effect this may have on the performance of medical staff in terms of patient examination, communication, decision-making, planning, and overall patient care. This study aims to close this knowledge gap. The investigators of this study aim to make rescue missions to high altitude safer for both the patients and the rescuers.
To assess the effect of high altitude on patient care, the investigators recruit highly trained medical specialists who will perform patient care in simulated scenarios both at high altitude and at low altitude. These scenarios will be recorded and the performance of the medical specialists judged by independent reviewers.
The medical specialists will also perform in simulated scenarios at high altitude two more times: once with supplementary oxygen, and once after spending a night at high altitude. the investigators do this to evaluate whether supplementary oxygen improves their performance, and whether symptoms of acute mountain sickness (which usually develop after spending the first night at high altitude) decreases their performance further.
详细描述
Rescue services in mountainous regions are frequently called to missions at altitudes >3000 m. Under the difficult conditions of acute exposure to altitude, the crews then have to undertake demanding medical and rescue measures, such as an emergency induction of anaesthesia, resuscitation, treatment of polytraumatized patients, or a winch manoeuvre by helicopter in exposed, fall-prone terrain.
The exponential decrease in barometric pressure at altitude results in hypobaric hypoxia (HH), leading to a reduction in the partial pressure of oxygen at every point along the oxygen transport chain from the ambient air to tissue mitochondria. If the body's adaptive mechanisms fail to compensate for the lack of oxygen, symptoms like headache, nausea, fatigue, and dizziness may occur. In addition, HH may impair higher cortical functions. Individuals affected by high altitude frequently do not recognise a decline in cognitive function and overall performance, which can lead to incidents and even fatal consequences.
Previous studies in non-medical personnel, such as astronauts, aircraft pilots, and military helicopter pilots have explored the influence of HH on multiple cognitive domains. Impairment of working memory was described during hypoxia awareness trainings and in pilots while others reported no effects. Some studies have reported reduced psychomotor vigilance, while others found no effects. To counteract these impairments, the European Union Aviation Safety Agency (EASA) mandates simulated hypoxia training for pilots flying rescue missions to above 4000 m.
Studies in medical personnel are few and mostly focused on the quality of cardiopulmonary resuscitation (CPR) at (simulated) high altitude. High-quality CPR, which can be physically demanding for rescuers even under normoxic conditions, leads to rescuer fatigue faster under HH. Two recent studies have shown that HH leads to a lower quality of CPR at simulated and natural high altitude. A smaller study found simulated altitude to have a negative effect on the quality of ventilation but not on chest compression. A recent study reported a slower reaction time in medical personnel at simulated high altitude. Particularly noteworthy is the fact that rescuers did neither notice the reduced cognitive function nor the decreased quality of CPR they provided under HH, even though they were highly trained helicopter emergency medical services personnel. To the investigators' knowledge, CPR at high altitude has only been studied as an isolated skill. No data exist on the performance of medical staff in terms of patient examination, communication, decision-making, planning, and overall patient care. This study aims to close this knowledge gap. The findings of this study may help to broaden the understanding of HH, and lay the ground for further research in high altitude rescue.
As the primary endpoint of this study, the investigators evaluate medical performance and patient care using validated scores for medical skills and non-technical skills (Modified Simulation Team Assessment Tool (STAT), Concise Assessment of Leader Management (CALM), Team Emergency Assessment Measure (TEAM). These three scores are averaged (25% STAT, 25% CALM, 50% TEAM) to form a composite score. Scores are assessed by an analysis of video recordings of the simulated scenarios by independent outside assessors.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Health Services Research
- 盲法
- Double (Participant, Outcomes Assessor)
盲法说明
Participants cannot be masked to whether they are at high or low altitude and whether they have spent a night at high altitude. However, they will not know whether they receive air (baseline, interventions 1 and 3) or supplementary oxygen nasally at the same flow rate (intervention 2).
Outcome Assessors will be fully blinded. They assess the medical performance on video recordings of the simulated scenarios, and will not know which time point a specific scenario has taken place (baseline, interventions 1-3) and whether participants receive air or supplementary oxygen.
入排标准
- 年龄范围
- 18 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Medical doctors with certification and experience in preclinical emergency medicine, defined as (all must apply):
- •2 or more years of training in anaesthesiology
- •3 or more months of preclinical work
- •50 or more cases as the lead preclinical physician with potential danger to the patient's life (with a National Advisory Committee for Aeronautics score (NACA) of 4 or more)
- •A valid preclinical certification (Swiss "Notarztkurs" or similar)
- •Written informed consent to participate in the study
排除标准
- •(none must apply):
- •Any medical condition known to place the participant at higher risk for hypoxia-induced adverse events (cardiovascular, pulmonary, neurological, otherwise).
- •Pre-acclimatisation to high altitude, defined as travel to above 2500 m in the 4 weeks previous to the study
结局指标
主要结局
The effect of acute high altitude exposure on medical performance, measured by the CALM score
时间窗: Baseline, intervention 1 (30 minutes after arriving at high altitude)
The investigators asses the quality of patient care at low and high altitude exposure. The primary outcome of the study - a composite score comprising three previously validated scores (25% CALM, 25% TEAM, 50% STAT) - will be analysed by means of a linear mixed-effect regression model to account for the longitudinal study design. In particular, each of the four time points represents a fixed effect (implemented with a factor variable) and a random offset for each participants is included in the model allowing to represent the repeated measurements and associated covariance structure. The analysis of the primary endpoint - the difference in the composite score between baseline and after acute altitude exposure (intervention 1) - will be performed by assessing the pairwise contrast of the estimated marginal means of the linear mixed-effect regression model.
The effect of acute high altitude exposure on medical performance, measured by the STAT score
时间窗: Baseline, intervention 1 (30 minutes after arriving at high altitude)
The investigators asses the quality of patient care at low and high altitude exposure. The primary outcome of the study - a composite score comprising three previously validated scores (25% CALM, 25% TEAM, 50% STAT) - will be analysed by means of a linear mixed-effect regression model to account for the longitudinal study design. In particular, each of the four time points represents a fixed effect (implemented with a factor variable) and a random offset for each participants is included in the model allowing to represent the repeated measurements and associated covariance structure. The analysis of the primary endpoint - the difference in the composite score between baseline and after acute altitude exposure (intervention 1) - will be performed by assessing the pairwise contrast of the estimated marginal means of the linear mixed-effect regression model.
The effect of acute high altitude exposure on medical performance, measured by the TEAM score
时间窗: Baseline, intervention 1 (30 minutes after arriving at high altitude)
The investigators asses the quality of patient care at low and high altitude exposure. The primary outcome of the study - a composite score comprising three previously validated scores (25% CALM, 25% TEAM, 50% STAT) - will be analysed by means of a linear mixed-effect regression model to account for the longitudinal study design. In particular, each of the four time points represents a fixed effect (implemented with a factor variable) and a random offset for each participants is included in the model allowing to represent the repeated measurements and associated covariance structure. The analysis of the primary endpoint - the difference in the composite score between baseline and after acute altitude exposure (intervention 1) - will be performed by assessing the pairwise contrast of the estimated marginal means of the linear mixed-effect regression model.
次要结局
- The correlations between vital parameters (blood pressure, heart rate, peripheral blood oxygen saturation) and medical performance during low altitude, acute and subacute high altitude exposure, measured as a composite of STAT, CALM, and TEAM scores(Baseline, intervention 1 (30 minutes after arriving at high altitude), intervention 2 (4 hours after arriving at high altitude, with supplementary oxygen), intervention 3 (after having spent a night at high altitude))
- The effect of subacute high altitude exposure on medical performance, measured as a composite of STAT, CALM, and TEAM scores(Baseline, intervention 1 (30 minutes after arriving at high altitude), intervention 3 (after having spent a night at high altitude))
- The effect of gender and age on medical performance during low altitude, acute and subacute high altitude exposure, measured as a composite of STAT, CALM, and TEAM scores(Baseline, intervention 1 (30 minutes after arriving at high altitude), intervention 2 (4 hours after arriving at high altitude, with supplementary oxygen), intervention 3 (after having spent a night at high altitude))
- The effect of supplementary oxygen on medical performance during acute high altitude exposure, measured as a composite of STAT, CALM, and TEAM scores(Baseline, intervention 1 (30 minutes after arriving at high altitude), intervention 2 (4 hours after arriving at high altitude, with supplementary oxygen))
- The correlations between psychomotor test results (PVT, BART, DSST, self-assessment of cognitive function) and medical performance during low altitude, acute and subacute high altitude exposure, measured as a composite of STAT, CALM, and TEAM scores(Baseline, intervention 1 (30 minutes after arriving at high altitude), intervention 2 (4 hours after arriving at high altitude, with supplementary oxygen), intervention 3 (after having spent a night at high altitude))