Su Po-Lan, Lin Wei-Chieh, Ko Yen-Fen, Cheng Kuo-Sung, Chen Chang-Wen
Institute of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan.
Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng-Kung University, Tainan, 70403 Taiwan.
J Med Biol Eng. 2021;41(6):888-894. doi: 10.1007/s40846-021-00668-2. Epub 2021 Nov 16.
The positive end-expiratory pressure (PEEP) level with best respiratory system compliance (Crs) is frequently used for PEEP selection in acute respiratory distress syndrome (ARDS) patients. On occasion, two similar best Crs (where the difference between the Crs of two PEEP levels is < 1 ml/cm HO) may be identified during decremental PEEP titration. Selecting PEEP under such conditions is challenging. The aim of this study was to provide supplementary rationale for PEEP selection by assessing the global and regional ventilation distributions between two PEEP levels in this situation.
Eight ARDS cases with similar best Crs at two different PEEP levels were analyzed using examination-specific electrical impedance tomography (EIT) measures and airway stress index (SIaw). Five Crs were measured at PEEP values of 25 cm HO (PEEP), 20 cm HO (PEEP), 15 cm HO (PEEP), 11 cm HO (PEEP), and 7 cm HO (PEEP). The higher PEEP value of the two PEEPs with similar best Crs was designated as PEEP, while the lower designated as PEEP.
PEEP and PEEP shared the best Crs in two cases, while similar Crs was found at PEEP and PEEP in the remaining six cases. SIaw was higher with PEEP as compared to PEEP (1.06 ± 0.10 versus 0.99 ± 0.09, p = 0.05). Proportion of lung hyperdistension was significantly higher with PEEP than PEEP (7.0 ± 5.1% versus 0.3 ± 0.5%, p = 0.0002). In contrast, proportion of recruitable lung collapse was higher with PEEP than PEEP (18.6 ± 4.4% versus 5.9 ± 3.7%, p < 0.0001). Cyclic alveolar collapse and reopening during tidal breathing was higher at PEEP than PEEP (34.4 ± 19.3% versus 16.0 ± 9.1%, p = 0.046). The intratidal gas distribution (ITV) index was also significantly higher at PEEP than PEEP (2.6 ± 1.3 versus 1.8 ± 0.7, p = 0.042).
PEEP is a rational selection in ARDS cases with two similar best Crs. EIT provides additional information for the selection of PEEP in such circumstances.
The online version contains supplementary material available at 10.1007/s40846-021-00668-2.
呼气末正压（PEEP）水平达到最佳呼吸系统顺应性（Crs）时常用于急性呼吸窘迫综合征（ARDS）患者的PEEP选择。有时，在递减PEEP滴定过程中可能会发现两个相似的最佳Crs（两个PEEP水平的Crs之差<1 ml/cm H₂O）。在这种情况下选择PEEP具有挑战性。本研究的目的是通过评估这种情况下两个PEEP水平之间的整体和区域通气分布，为PEEP选择提供补充依据。
使用特定检查的电阻抗断层扫描（EIT）测量和气道应力指数（SIaw）分析8例在两个不同PEEP水平具有相似最佳Crs的ARDS病例。在25 cm H₂O（PEEP₁）、20 cm H₂O（PEEP₂）、15 cm H₂O（PEEP₃）、11 cm H₂O（PEEP₄）和7 cm H₂O（PEEP₅）的PEEP值下测量五个Crs。两个具有相似最佳Crs的PEEP中较高的PEEP值指定为PEEP₁，较低的指定为PEEP₂。
在2例中PEEP₁和PEEP₂具有相同的最佳Crs，而在其余6例中PEEP₁和PEEP₂的Crs相似。与PEEP₂相比，PEEP₁时的SIaw更高（1.06±0.10对0.99±0.09，p = 0.05）。PEEP₁时肺过度膨胀的比例显著高于PEEP₂（7.0±5.1%对0.3±0.5%，p = 0.0002）。相比之下，PEEP₁时可复张肺萎陷的比例高于PEEP₂（18.6±4.4%对5.9±3.7%，p < 0.0001）。潮气呼吸期间周期性肺泡萎陷和重新开放在PEEP₁时高于PEEP₂（34.4±19.3%对16.0±9.1%，p = 0.046）。潮气内气体分布（ITV）指数在PEEP₁时也显著高于PEEP₂（2.6±1.3对1.8±0.7，p = 0.042）。
在具有两个相似最佳Crs的ARDS病例中，PEEP₁是合理的选择。EIT在此类情况下为PEEP的选择提供了额外信息。
在线版本包含可在10.1007/s40846-021-00668-2获取的补充材料。
