Li Yang, Tang Rui, Huang Ying-Zi, Zhang Yun-Hang, Mao Zi-Ruo, Pan Chun, Liu Song-Qiao, Guo Feng-Mei, Yang Yi, Qiu Hai-Bo
Department of Critical Care Medicine, Zhongda Hospital and School of Clinical Medicine, Southeast University, Nanjing 210009, China.
Zhonghua Nei Ke Za Zhi. 2013 Apr;52(4):295-8.
To evaluate the precision and feasibility of nitrogen washout/washin method in assessing lung recruitment of acute lung injury (ALI) patients.
Fifteen ALI patients underwent mechanical ventilation were involved. Two positive end-expiratory pressure (PEEP) levels (high and low) were adjusted according to ARDSnet recommendations or measurement of transpulmonary pressure, each for 30 minutes. Tidal volume (Vt), plateau of airway pressure (Pplat), other respiratory mechanics, gas-exchange and hemodynamics were measured. End expiration lung volume (EELV) was measured at different PEEP levels through nitrogen washout/washin method, and formula (EELVhighPEEP-EELVlowPEEP)-VtlowPEEP/(PplatlowPEEP-PEEPlowPEEP)×(PEEPhigh-PEEPlow) was used as recruitment (Rec-N2). Alveolar recruitment was measured using pressure-volume (P-V) curves (Rec-mes). Correlation and consistency of Rec-N2 and Rec-mes were compared by correlation analysis and Bland-Altman technique.
PEEP titrated by ARDSnet recommendations or transpulmonary pressure were (7 ± 2) cm H2O (1 cm H2O = 0.098 kPa) vs (14 ± 5) cm H2O (P = 0.008); and there were significant differences in peak pressure (23 ± 5) cm H2O vs (28 ± 6) cm H2O, plateau of airway pressure (17 ± 4)cm H2O vs (22 ± 6) cm H2O, esophageal pressure, transpulmonary pressure and other respiratory mechanics between the two PEEP levels (P < 0.05). The P-V curve technique gave Rec-mes a value of 100 (-25 ∼ 185)ml. The nitrogen washout/washin technique gave Rec-N2 a value of 180 (-19 ∼ 255) ml, which showed a good correlation with a bias of 46 (8 ∼ 80) ml (R(2) = 0.755, P < 0.0001).
Nitrogen washout/washin technique can be used to determine lung recruitment volume of ALI patients.
评估氮洗出/洗入法在评估急性肺损伤（ALI）患者肺复张中的准确性和可行性。
纳入15例接受机械通气的ALI患者。根据ARDSnet推荐或跨肺压测量调整两个呼气末正压（PEEP）水平（高和低），每个水平持续30分钟。测量潮气量（Vt）、气道平台压（Pplat）、其他呼吸力学、气体交换和血流动力学。通过氮洗出/洗入法在不同PEEP水平测量呼气末肺容积（EELV），并使用公式（EELV高PEEP - EELV低PEEP）- Vt低PEEP /（Pplat低PEEP - PEEP低PEEP）×（PEEP高 - PEEP低）作为复张量（Rec - N2）。使用压力 - 容积（P - V）曲线测量肺泡复张量（Rec - mes）。通过相关性分析和Bland - Altman技术比较Rec - N2和Rec - mes的相关性和一致性。
根据ARDSnet推荐或跨肺压滴定的PEEP分别为（7±2）cm H2O（1 cm H2O = 0.098 kPa）与（14±5）cm H2O（P = 0.008）；两个PEEP水平之间的峰值压力（23±5）cm H2O与（28±6）cm H2O、气道平台压（17±4）cm H2O与（22±6）cm H2O、食管压力、跨肺压和其他呼吸力学存在显著差异（P < 0.05）。P - V曲线技术测得Rec - mes值为100（-25～185）ml。氮洗出/洗入技术测得Rec - N2值为180（-19～255）ml，两者显示出良好的相关性，偏差为46（8～80）ml（R(2)=0.755，P < 0.0001）。
氮洗出/洗入技术可用于确定ALI患者的肺复张量。
