不同肺复张模式对急性呼吸窘迫综合征患者呼吸功能及血管外肺水指数的影响

Effects of Various Lung Recruitment Maneuvers on Respiratory Function and Extravascular Lung Water Index in Patients with ARDS

目的探讨控制性肺膨胀(SI)和压力控制(PCV)两种肺复张(RM)对急性呼吸窘迫综合征(ARDS)患者呼吸力学及血管外肺水指数(EVLWI)的影响。方法采用随机对照病例研究方法,选择30例ARDS患者,随机分为SI组和PCV组,每组15例。SI组:保护性肺通气稳定0.5h后呼吸机模式改为持续正压通气(3.92kPa),持续40s;PCV组:呼吸机模式改为PCV,吸气压力(Pessure above PEEP,1.96kPa),I∶E=1∶1,持续2min。肺复张结束后,2组均恢复呼吸机基础参数。每12h重复1次RM,连续3d。收集2组患者治疗前,治疗12、24、48、72h各时间点氧合指数(PaO2/FiO2)、气道峰压(PIP)、气道平台压(Pplat)、静态肺顺应性(Cst)及EVLWI;监测每次RM前后血流动力学变化。结果 1)治疗后2组患者PaO2/FiO2、Cst均呈上升趋势(P<0.05或P<0.01),PIP、Pplat值在治疗后均呈下降趋势,但在各时间点2组比较差异无统计学意义(P>0.05)。2)治疗后2组EVLWI均呈下降趋势(P<0.01),但各时间点2组比较差异无统计学意义(P>0.05)。3)2组患者在肺复张时平均动脉压、心脏指数下降,心率、中心静脉压升高,与复张前比较差异有统计学意义(P<0.01),PCV组上述指标波动幅度及持续时间均低于SI组,在肺复张时、复张后2min、复张后5min上述指标比较差异有统计学意义(P<0.01)。结论 SI与PCV两种肺复张均能改善肺氧合及肺顺应性,减少ARDS患者EVLWI,PCV肺复张对血流动力学影响低于SI。

Objective To investigate the effects of lung recruitment maneuvers（RMs） with sustained inflation（SI）and pressure control ventilation（PCV） on respiratory mechanics and extravascular lung water index（EVLWI） in patients with acute respiratory distress syndrome（ARDS）.Methods After 0.5 hours of stable lung protective ventilation,30 patients with ARDS were randomized to receive either continuous positive airway pressure（CPAP） of 3.92 kPa for 40 seconds（SI group,n=15） or positive-end expiratory pressure of 1.96 kPa（I∶E = 1∶1） for 2 minutes（PCV group,n=15）.RMs were performed once every 12 hours for 3 days.Oxygenation index（PaO2/FiO2）,peak inspiratory pressure（PIP）,plateau pressure（Pplat）,static pulmonary compliance（Cst） and EVLWI were measured before treatment and at 12,24,48 and 72 hours after treatment.In addition,changes in hemodynamics were monitored before and after RMs.Results The PaO2/FiO2 and Cst significantly increased after treatment in both groups（P0.05 orP0.01）.The PIP and Pplat showed downward trend after treatment,but the differences were not significant between the two groups（P0.05）.The EVLWI obviously decreased after treatment（P0.01）,but there were no significant differences between the two groups（P0.05）.Furthermore,mean arterial pressure and cardiac index decreased and heart rate and central venous pressure increased during RMs compared with the values before RMs（P0.01）.Compared with SI group,the amplitude and duration of these parameters significantly decreased in PCV group during RMs and at 2 and 5 minutes after RMs（P0.01）.Conclusion RMs with PCV and SI can reduce EVLWI and increase oxygenation and lung compliance in patients with ARDS.Moreover,SI RM has a greater effect than PCV RM on hemodynamics.