Sedation practitioner, Rijnstate Hospital, Arnhem, The Netherlands.
Anaesthesiologist-Intensivist, Rijnstate Hospital, Arnhem, The Netherlands.
J Clin Monit Comput. 2024 Dec;38(6):1397-1404. doi: 10.1007/s10877-024-01185-8. Epub 2024 Jun 12.
This study tests if the pressure variation in the HFNC-system may allow for monitoring of respiratory rate and the pressure difference during breathing may be a marker of respiratory effort.
A HFNC system (Fisher & Paykel Optiflow Thrive 950) was modified by adding a GE Healthcare D-Lite spirometry sensor attached to a respiratory module and a pressure transducer. Participants were instructed to breathe regularly, quickly and slowly during 4 different conditions (HFNC flow 30 l/min and 70 l/min and with an open and closed mouth). Respiratory rate was counted based on pressure variation shown on the monitor graphs and compared with the count by observation of the participant. The pressure difference between inspiration and expiration was tested for correlation with the respiratory rate, as a surrogate marker for respiratory effort.
Twenty five participants were included in this study. False detection of apnea in pressure-based measurements occurred in 10% and 11% of the measurements with open mouth position at 30 l/min and 70 l/min HFNC-flow, respectively, but not with a closed mouth. The 95% Limits of Agreement were - 1.85;1.91, -13.72;9,88, -2.25;2.47, -30.32;19.93 for the conditions of 30 l/min -closed mouth, 30 l/min - open mouth, 70 l/min - closed mouth and 70 l/min - open mouth, respectively. There was a correlation between pressure difference and respiratory effort, except for the condition of 30 l/min with open mouth.
The pressure variation in the HFNC system allows for respiratory rate and effort monitoring, but requires further development to increase precision.
ClinicalTrials.gov (NCT05991843).
本研究旨在检验 HFNC 系统中的压力变化是否可用于监测呼吸频率，以及呼吸过程中的压力差是否可作为呼吸努力的标志物。
通过在 HFNC 系统（Fisher & Paykel Optiflow Thrive 950）上添加一个连接到呼吸模块和压力传感器的通用电气医疗 D-Lite 肺活量传感器，对其进行了改装。参与者被指示在 4 种不同条件下（HFNC 流量 30 l/min 和 70 l/min 以及口张开和闭合）进行有规律地、快速地和缓慢地呼吸。根据监测器图形上显示的压力变化计算呼吸频率，并与观察参与者呼吸的次数进行比较。测试了吸气和呼气之间的压力差与呼吸率的相关性，作为呼吸努力的替代标志物。
本研究共纳入 25 名参与者。在 HFNC 流量为 30 l/min 和 70 l/min 时口张开的情况下，压力测量分别有 10%和 11%出现了假阳性呼吸暂停，但口闭合时未出现这种情况。条件为 30 l/min 闭口、30 l/min 开口、70 l/min 闭口和 70 l/min 开口时，95%一致性界限分别为-1.85;1.91、-13.72;9、-2.25;2.47、-30.32;19.93。在 30 l/min 开口、70 l/min 闭口和 70 l/min 开口这三种条件下，压力差与呼吸努力之间存在相关性，但需要进一步开发以提高精度。
HFNC 系统中的压力变化可用于监测呼吸频率和努力程度，但需要进一步开发以提高精度。
ClinicalTrials.gov（NCT05991843）。
