膈肌紧张性电位指导急性呼吸窘迫综合征呼气末正压选择的实验研究

Adjustment of positive end-expiratory pressure during presence of tonic diaphragm electrical activity in rabbits with acute respiratory distress syndrome

目的探讨利用膈肌紧张性电位（tonic diaphragm electrical activity EAdi，TonicEAdi）选择急性呼吸窘迫综合征（ARDS）呼气末正压（PEEP）的可行性。方法盐酸吸入法复制兔ARDS模型，充分肺复张后随机（随机数字法）分为TonicEAdi组和氧合法组，分别利用TonicEAdi法或氧合法选择PEEP，观察TonicEAdi组与氧合法组PEEP及其对呼吸力学以及气体交换的影响。两独立样本的比较用t检验，以P〈0．05表示差异具有统计学意义。结果（1）PEEP：TonicEAdi组为（10．7±1．4）cmH2O（1cmH2O=0．098kPa），氧合法组为（10．0±2．8）cmH2O，组间比较差异无统计学意义（P〉0．05）；（2）呼吸力学：PEEP选择后，与氧合法组比较，TonicEAdi组在潮气量（VT）、气道峰压（Ppeak）、气道平均压（Pmean）方面差异均无统计学意义（均P〉0．05）；（3）气体交换：PEEP选择后，与氧合法组比较，Tonic EAdi组在氧合指数（PaO2／FiO2）、动脉血二氧化碳分压（PaCO2）方面差异无统计学意义（均P〉0．05）。结论Tonic EAdi可以用来指导ARDS PEEP的选择。

Objective To study the positive end-expiratory pressure （PEEP） adjustment after recruitment maneuvers during acute respiratory distress syndrome （ARDS） especially in the presence of tonic diaphragm electrical activity （Tonic EAdi） in order to obtain optimum PEEP and in turn to get successful oxygenation. Methods Rabbit model of ARDS was made by intratracheal instillation of hydrochloric acid. After sufficient recruitment maneuvers, the rabbits were randomly （random number） divided into two groups, namely Tonic EAdi group （ n = 5 ） and maximum oxygenation group （ n = 5 ）. In Tonic EAdi group, the regulation of PEEP was guided by Tonic EAdi. In maximum oxygenation group, PEEP was adjusted as per maximum oxygenation. The differences in magnitude of PEEP, pulmonary mechanics, gas exchange and hemodynamics were compared between two groups. The t-test was used to compare continuous variables between the two independent samples, and the difference was statistically significant when P 〈 0. 05. Results （1） PEEP： The PEEP was （10.7 ± 1.4） cm H2O （1 cm H2O =0.098 kPa） in Tonic EAdi group and （10.0 ± 2.8） cm H2O in maximum oxygenation group （P 〉 0.05）. （2） Pulmonary mechanics： After PEEP adjustment, there was no significant differeuce in tidal volume （ VT ） , peak pressure （ Ppeak ） and mean pressure （ Pmean ） between the two groups （ P 〉 0. 05 ）. （ 3 ） Gas exchange： After PEEP adjustment, there was no significant difference in oxygenation index （PaO2/FiO2 ） and partial pressure of arterial carbon dioxide （ PaCO2 ） between the two groups （ P 〉 0. 05 ）. Conclusions Tonh. EAdi couhl be a good indiicator for regulating PEEP in ARDS.