Abstract：
BACKGROUND: High-flow tracheal oxygen (HFTO) is being used as supportive therapy during weaning in tracheostomized patients difficult to wean from invasive mechanical ventilation. There is, however, no clinical evidence for such a strategy. Therefore, we conducted a systematic review to summarize studies evaluating the physiologic effects of HFTO during tracheostomy-facilitated weaning and to identify potential areas for future research in this field.
METHODS: Observational and interventional studies on critically ill subjects weaning from mechanical ventilation via tracheostomy published until December 22, 2022, were eligible. Studies on high-flow oxygen, only in children, non-human models or animals, on clinical outcome only, abstracts without full-text availability, case reports, and reviews were excluded. Main outcomes were end-expiratory lung volume (EELV) and tidal volume using electrical impedance tomography, respiratory effort assessed by esophageal manometry, work of breathing and neuroventilatory drive as assessed by electrical activity of the diaphragm (EAdi) signal, airway pressure (Paw), oxygenation (PaO2 /FIO2 or SpO2 /FIO2 ), breathing frequency, tidal volume, and PaCO2 .
RESULTS: In total, 1,327 references were identified, of which 5 were included. In all studies, HFTO was administered with flow 50 L/min and compared to conventional O2 therapy in a crossover design. The total average duration of invasive ventilation at time of measurements ranged from 11-27 d. In two studies, PaO2 /FIO2 and mean Paw were higher with HFTO. EELV, tidal volumes, esophageal pressure swings, and EAdi were similar during high-flow tracheal oxygen and conventional O2 therapy.
CONCLUSIONS: The main physiological effect of HFTO as compared to conventional O2 therapy in tracheostomized subjects weaning from mechanical ventilation was improved oxygenation that is probably flow-dependent. Respiratory effort, lung aeration, neuroventilatory drive, and ventilation were similar for HFTO and conventional O2 therapy. Future studies on HFTO should be performed early in the weaning process and should evaluate its effect on sputum clearance and patient-centered outcomes like dyspnea.
METHODS: Observational and interventional studies on critically ill subjects weaning from mechanical ventilation via tracheostomy published until December 22, 2022, were eligible. Studies on high-flow oxygen, only in children, non-human models or animals, on clinical outcome only, abstracts without full-text availability, case reports, and reviews were excluded. Main outcomes were end-expiratory lung volume (EELV) and tidal volume using electrical impedance tomography, respiratory effort assessed by esophageal manometry, work of breathing and neuroventilatory drive as assessed by electrical activity of the diaphragm (EAdi) signal, airway pressure (Paw), oxygenation (PaO2 /FIO2 or SpO2 /FIO2 ), breathing frequency, tidal volume, and PaCO2 .
RESULTS: In total, 1,327 references were identified, of which 5 were included. In all studies, HFTO was administered with flow 50 L/min and compared to conventional O2 therapy in a crossover design. The total average duration of invasive ventilation at time of measurements ranged from 11-27 d. In two studies, PaO2 /FIO2 and mean Paw were higher with HFTO. EELV, tidal volumes, esophageal pressure swings, and EAdi were similar during high-flow tracheal oxygen and conventional O2 therapy.
CONCLUSIONS: The main physiological effect of HFTO as compared to conventional O2 therapy in tracheostomized subjects weaning from mechanical ventilation was improved oxygenation that is probably flow-dependent. Respiratory effort, lung aeration, neuroventilatory drive, and ventilation were similar for HFTO and conventional O2 therapy. Future studies on HFTO should be performed early in the weaning process and should evaluate its effect on sputum clearance and patient-centered outcomes like dyspnea.
摘要：
背景：高流量气管吸氧（HFTO）在气管造口术难以脱离有创机械通气的患者断奶期间被用作支持治疗。有,然而,没有这种策略的临床证据。因此,我们进行了系统综述,以总结评估HFTO在气管造口辅助断奶过程中的生理效应的研究,并确定该领域未来研究的潜在领域.
方法：在2022年12月22日之前发表的关于通过气管造口术从机械通气撤机的危重病受试者的观察性和介入性研究符合资格。高流量氧气的研究,只有在儿童中，非人类模型或动物，仅在临床结果上，没有全文可用性的摘要，病例报告,和评论被排除在外。主要结果为呼气末肺容积（EELV）和潮气量，使用电阻抗断层显像，通过食管测压评估呼吸努力，通过隔膜（EAdi）信号的电活动评估的呼吸和神经通气驱动工作，气道压力（Paw），氧合（PaO2/FIO2或SpO2/FIO2），呼吸频率,潮气量,PaCO2
结果：总计，确定了1,327个参考文献，其中包括5个。在所有研究中,HFTO以50升/分钟的流量给药，并以交叉设计与常规O2治疗进行比较。测量时有创通气的总平均持续时间为11-27d。在两项研究中，HFTO组PaO2/FIO2和平均Paw较高。EELV,潮气量,食管压力波动,在高流量气管吸氧和常规O2治疗期间，EAdi和EAdi相似。
结论：在脱离机械通气的气管造口术患者中，与常规O2治疗相比，HFTO的主要生理作用是改善氧合，这可能是流量依赖性的。呼吸努力，肺通气,神经通气驱动,HFTO和常规O2治疗的通气相似。未来对HFTO的研究应在断奶过程的早期进行，并应评估其对痰液清除和以患者为中心的预后如呼吸困难的影响。
方法：在2022年12月22日之前发表的关于通过气管造口术从机械通气撤机的危重病受试者的观察性和介入性研究符合资格。高流量氧气的研究,只有在儿童中，非人类模型或动物，仅在临床结果上，没有全文可用性的摘要，病例报告,和评论被排除在外。主要结果为呼气末肺容积（EELV）和潮气量，使用电阻抗断层显像，通过食管测压评估呼吸努力，通过隔膜（EAdi）信号的电活动评估的呼吸和神经通气驱动工作，气道压力（Paw），氧合（PaO2/FIO2或SpO2/FIO2），呼吸频率,潮气量,PaCO2
结果：总计，确定了1,327个参考文献，其中包括5个。在所有研究中,HFTO以50升/分钟的流量给药，并以交叉设计与常规O2治疗进行比较。测量时有创通气的总平均持续时间为11-27d。在两项研究中，HFTO组PaO2/FIO2和平均Paw较高。EELV,潮气量,食管压力波动,在高流量气管吸氧和常规O2治疗期间，EAdi和EAdi相似。
结论：在脱离机械通气的气管造口术患者中，与常规O2治疗相比，HFTO的主要生理作用是改善氧合，这可能是流量依赖性的。呼吸努力，肺通气,神经通气驱动,HFTO和常规O2治疗的通气相似。未来对HFTO的研究应在断奶过程的早期进行，并应评估其对痰液清除和以患者为中心的预后如呼吸困难的影响。
