Department of Adult Critical Care, Guy's and St Thomas' NHS Foundation Trust, King's Health Partners, London, UK.
Centre of Human & Applied Physiological Sciences, King's College London, London, UK.
Perfusion. 2020 May;35(1_suppl):57-64. doi: 10.1177/0267659120908115.
The criteria and process for liberation from extracorporeal membrane oxygenation in patients with severe acute respiratory distress syndrome are not standardized. The predictive accuracy of the oxygen challenge test as a diagnostic test in determining weaning and decannulation from venovenous extracorporeal membrane oxygenation was tested.
A single-centre, retrospective, observational cohort study.
Tertiary referral severe respiratory failure centre in a university hospital in the United Kingdom.
253 adults with severe acute respiratory distress syndrome requiring extracorporeal membrane oxygenation.
None.
Patients had median age: 43 years (interquartile range: 32-52) years, extracorporeal membrane oxygenation days: 9 (interquartile range: 6-14) and acute physiology and chronic health evaluation II score 17.5 (interquartile range: 15-20). Oxygen challenge test value (PaO) with best prediction was 31 kPa (232 mmHg; sensitivity 0.74; specificity 0.70; area under curve 0.77 (confidence interval: 0.73-0.81)). PaO did not perform well as a prospective test to identify readiness to decannulation. Only 24 patients (10%) were decannulated 48 hours after their first positive oxygen challenge test (true positive) and 73.4% patients were false positives (positive oxygen challenge test but not decannulated). True positives had higher tidal volume (541 ± 218 vs 368 mL ± 210; p < 0.05) and minute ventilation (9.34 ± 5.36 vs 6.33 L/min ± 4.43; p < 0.05). Blood flow (3.17 ± 0.23 vs 3.53 L/min ± 0.56; p < 0.05), sweep gas flow (1.42 ±1.83 vs 3.74 L/min ± 2.43; p < 0.05) and extracorporeal membrane oxygenation minute volume at time of first positive oxygen challenge test was lower in true positives (1.66 ± 2.26 vs 4.82 ± 3.43 L/min). This was a strong predictor for decannulation within 48 hours (area under curve: 0.88, confidence interval: 0.88-0.89).
In severe acute respiratory distress syndrome requiring venovenous extracorporeal membrane oxygenation, the PaO is a poor predictor of readiness to decannulate from extracorporeal membrane oxygenation. Additional factors involved in the control of respiratory drive and carbon dioxide clearance, particularly native lung dead space and total minute ventilation, should be assessed.
严重急性呼吸窘迫综合征患者脱离体外膜肺氧合的标准尚不明确。本研究旨在检验氧挑战试验作为一种诊断试验，在确定是否可从静脉-静脉体外膜肺氧合撤机和拔管方面的预测准确性。
单中心、回顾性、观察性队列研究。
英国一所大学附属医院的三级转诊严重呼吸衰竭中心。
253 例需要体外膜肺氧合的严重急性呼吸窘迫综合征成人患者。
无。
患者的中位年龄为 43 岁（四分位间距：32-52 岁），体外膜肺氧合时间为 9 天（四分位间距：6-14 天），急性生理学和慢性健康评估 II 评分 17.5 分（四分位间距：15-20 分）。氧挑战试验值（PaO）预测效果最佳，为 31 kPa（232 mmHg；敏感性 0.74；特异性 0.70；曲线下面积 0.77（置信区间：0.73-0.81））。PaO 并不能很好地作为预测拔管时机的前瞻性试验。只有 24 例患者（10%）在首次阳性氧挑战试验后 48 小时拔管（真阳性），73.4%的患者为假阳性（阳性氧挑战试验但未拔管）。真阳性患者的潮气量（541±218 比 368 mL±210；p<0.05）和分钟通气量（9.34±5.36 比 6.33 L/min±4.43；p<0.05）更高。真阳性患者的血流量（3.17±0.23 比 3.53 L/min±0.56；p<0.05）、扫气流量（1.42±1.83 比 3.74 L/min±2.43；p<0.05）和首次阳性氧挑战试验时的体外膜肺氧合分钟通气量更低。这是 48 小时内拔管的一个强预测因素（曲线下面积：0.88，置信区间：0.88-0.89）。
在需要静脉-静脉体外膜肺氧合的严重急性呼吸窘迫综合征患者中，PaO 是预测能否脱离体外膜肺氧合的一个较差指标。应评估与呼吸驱动和二氧化碳清除控制相关的其他因素，特别是肺内死腔和总分钟通气量。
