Critical Care Unit, Royal Free Hospital, London, UK.
Division of Surgery and Interventional Science, Royal Free Hospital, University College London, London, UK.
BMJ Open. 2019 Jan 17;9(1):e021674. doi: 10.1136/bmjopen-2018-021674.
Oxygen is the most commonly administered drug to mechanically ventilated critically ill adults, yet little is known about the optimum oxygen saturation (SpO) target for these patients; the current standard of care is an SpO of 96% or above. Small pilot studies have demonstrated that permissive hypoxaemia (aiming for a lower SpO than normal by using a lower fractional inspired oxygen concentration (FIO)) can be achieved in the critically ill and appears to be safe. This approach has not been evaluated in a National Health Service setting. It is possible that permissive hypoxaemia may be beneficial to critically ill patients thus it requires robust evaluation.
Targeted OXygen therapY in Critical illness (TOXYC) is a feasibility randomised controlled trial (RCT) to evaluate whether recruiting patients to a study of permissive hypoxaemia is possible in the UK. It will also investigate biological mechanisms that may underlie the links between oxygenation and patient outcomes. Mechanically ventilated patients with respiratory failure will be recruited from critical care units at two sites and randomised (1:1 ratio) to an SpO target of either 88%-92% or ≥96% while intubated with an endotracheal tube. Clinical teams can adjust FIO and ventilator settings as they wish to achieve these targets. Clinical information will be collected before, during and after the intervention and blood samples taken to measure markers of systemic oxidative stress. The primary outcome of this study is feasibility, which will be assessed by recruitment rate, protocol adherence and withdrawal rates. Secondary outcomes will include a comparison of standard critical care outcome measures between the two intervention groups, and the measurement of biomarkers of systemic oxidative stress. The results will be used to calculate a sample size, likely number of sites and overall length of time required for a subsequent large multicentre RCT.
This study was approved by the London - Harrow Research Ethics Committee on 2 November 2017 (REC Reference 17/LO/1334) and received HRA approval on 13 November 2017. Results from this study will be disseminated in peer-reviewed journals, at medical and scientific meetings, in the NIHR Journals Library and patient information websites.
NCT03287466; Pre-results.
氧气是机械通气危重症成人最常用的药物，但人们对这些患者的最佳血氧饱和度（SpO2）目标知之甚少；目前的治疗标准是 SpO2 达到 96%或以上。小型试点研究表明，在危重病患者中可以实现允许性低氧血症（通过使用较低的吸入氧分数（FIO）来达到低于正常的 SpO2），并且似乎是安全的。这种方法尚未在国民保健服务体系中进行评估。允许性低氧血症可能对危重病患者有益，因此需要进行强有力的评估。
Targeted OXygen therapY in Critical illness（TOXYC）是一项可行性随机对照试验（RCT），旨在评估在英国招募患者参加允许性低氧血症研究是否可行。它还将研究可能存在于氧合与患者结局之间联系的生物学机制。呼吸衰竭的机械通气患者将从两个地点的重症监护病房招募，并随机（1:1 比例）分为 SpO2 目标为 88%-92%或≥96%，同时通过气管内插管进行插管。临床团队可以根据需要调整 FIO 和呼吸机设置以达到这些目标。将在干预前后收集临床信息，并采集血液样本以测量全身氧化应激标志物。该研究的主要结果是可行性，将通过招募率、方案依从性和退出率进行评估。次要结果将包括比较两组干预措施之间的标准重症监护结局测量值，以及测量全身氧化应激的生物标志物。结果将用于计算样本量、可能的站点数量和后续大规模多中心 RCT 所需的总时间。
该研究于 2017 年 11 月 2 日获得伦敦-哈罗研究伦理委员会的批准（REC 参考 17/LO/1334），并于 2017 年 11 月 13 日获得 HRA 批准。该研究的结果将发表在同行评议的期刊上，在医学和科学会议上，在 NIHR 期刊库和患者信息网站上。
NCT03287466；预结果。
