背景:无创通气(NIV)被广泛用作阻塞性肺疾病慢性急性加重(AECOPD)患者的初始治疗。然而,高流量鼻插管(HFNC)已被越来越多地使用和研究,以减轻与NIV相关的问题。在AECOPD恢复的受试者中,流速可能在膈肌功能中起重要作用。基于这些观察,我们进行了一项生理研究,以评估HFNC治疗对膈肌功能的影响,以美国衡量,呼吸频率(RR),气体交换,和病人的舒适在各种流量。
方法:一项前瞻性生理试验研究招募了诊断为AECOPD且需要NIV超过24小时的受试者。这些受试者在不同的连续流速(30~60L/min)下使用NIV和HFNC进行了30分钟试验.每次审判结束时,膈肌位移(DD,cm)和膈肌厚度分数(DTF,%)使用超声测量。此外,其他生理变量,如RR,气体交换,和病人的舒适,被记录下来。
结果:共20例患者纳入研究。试验中DD没有差异(p=0.753)。与HFNC-50和60L/min相比,HFNC-30L/min的DTF(%)显著更低(所有比较的p<0.001)。在停止NIV和HFNC试验结束时,动脉pH和PaCO2没有发现显着差异(p>0.050)。在HFNC试验期间,RR保持不变,无统计学差异(p=0.611)。然而,我们观察到,与NIV相比,HFNC改善了舒适度(所有比较p<0.001).有趣的是,30和40L/min的HFNC在试验期间显示出更大的舒适度。
结论:在从AECOPD恢复并接受HFNC的受试者中,流量超过40升/分钟可能不会提供额外的好处,在舒适和减少呼吸努力。在中断NIV期间,HFNC可能是COT的合适替代品。
BACKGROUND: Noninvasive ventilation (NIV) is widely employed as the initial treatment for patients with chronic acute exacerbation of obstructive pulmonary disease (AECOPD). Nevertheless, high-flow nasal cannula (HFNC) has been increasingly utilized and investigated to mitigate the issues associated with NIV. Flow rate may play a significant role in diaphragmatic function among subjects recovering from AECOPD. Based on these observations, we conducted a physiological study to assess the impact of HFNC therapy on diaphragmatic function, as measured by US, respiratory rate (RR), gas exchange, and patient comfort at various flow rates.
METHODS: A prospective physiological pilot study enrolled subjects with a diagnosis of AECOPD who required NIV for more than 24 h. After stabilization, these subjects underwent a 30-min trial using NIV and HFNC at different sequential flow rates (30-60 L/min). At the end of each trial, diaphragmatic displacement (DD, cm) and diaphragmatic thickness fraction (DTF, %) were measured using ultrasound. Additionally, other physiological variables, such as RR, gas exchange, and patient comfort, were recorded.
RESULTS: A total of 20 patients were included in the study. DD was no different among trials (p = 0.753). DTF (%) was significantly lower with HFNC-30 L/min compared to HFNC-50 and 60 L/min (p < 0.001 for all comparisons). No significant differences were found in arterial pH and PaCO2 at discontinuation of NIV and at the end of HFNC trials (p > 0.050). During HFNC trials, RR remained unchanged without statistically significant differences (p = 0.611). However, we observed that HFNC improved comfort compared to NIV (p < 0.001 for all comparisons). Interestingly, HFNC at 30 and 40 L/min showed greater comfort during trials.
CONCLUSIONS: In subjects recovering from AECOPD and receiving HFNC, flows above 40 L/min may not offer additional benefits in terms of comfort and decreased respiratory effort. HFNC could be a suitable alternative to COT during breaks off NIV.