Caruana L R, Barnett A G, Tronstad O, Paratz J D, Chang A T, Fraser J F
Physiotherapist, The Critical Care Research Group, The Prince Charles Hospital, The University of Queensland School of Medicine, Brisbane, Queensland.
Associate Professor, The Critical Care Research Group, The Prince Charles Hospital, School of Public Health & Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland.
Anaesth Intensive Care. 2017 Mar;45(2):235-243. doi: 10.1177/0310057X1704500214.
The reproducibility of the regional distribution of ventilation and the timing of onset of regional filling as measured by electrical impedance tomography lacks evidence. This study investigated whether electrical impedance tomography measurements in healthy males were reproducible when electrodes were replaced between measurements. Part 1: Recordings of five volunteers lying supine were made using electrical impedance tomography and a pneumotachometer. Measurements were repeated at least three hours later. Skin marking ensured accurate replacement of electrodes. No stabilisation period was allowed. Part 2: Electrical impedance tomography recordings of ten volunteers; a 15 minute stabilisation period, extra skin markings, and time-averaging were incorporated to improve the reproducibility. Reproducibility was determined using the Bland-Altman method. To judge the transferability of the limits of agreement, a Pearson correlation was used for electrical impedance tomography tidal variation and tidal volume. Tidal variation was judged to be reproducible due to the significant correlation between tidal variation and tidal volume (r = 0.93). The ventilation distribution was not reproducible. A stabilisation period, extra skin markings and time-averaging did not improve the outcome. The timing of regional onset of filling was reproducible and could prove clinically valuable. The reproducibility of the tidal variation indicates that non-reproducibility of the ventilation distribution was probably a biological difference and not measurement error. Other causes of variability such as electrode placement variability or lack of stabilisation when accounted for did not improve the reproducibility of the ventilation distribution.
通过电阻抗断层扫描测量的通气区域分布的可重复性以及区域充盈开始时间缺乏证据。本研究调查了在测量之间更换电极时，健康男性的电阻抗断层扫描测量是否具有可重复性。第1部分：使用电阻抗断层扫描和呼吸流速仪对五名仰卧志愿者进行记录。至少三小时后重复测量。皮肤标记确保电极的准确更换。不允许有稳定期。第2部分：对十名志愿者进行电阻抗断层扫描记录；纳入15分钟的稳定期、额外的皮肤标记和时间平均以提高可重复性。使用Bland-Altman方法确定可重复性。为了判断一致性界限的可转移性，对电阻抗断层扫描潮气量变化和潮气量使用Pearson相关性。由于潮气量变化与潮气量之间存在显著相关性（r = 0.93），因此判断潮气量变化具有可重复性。通气分布不可重复。稳定期、额外的皮肤标记和时间平均并未改善结果。区域充盈开始时间具有可重复性，并且可能具有临床价值。潮气量变化的可重复性表明通气分布的不可重复性可能是生物学差异而非测量误差。当考虑到其他变异性原因，如电极放置变异性或缺乏稳定性时，并未改善通气分布的可重复性。
