Abstract:

Objective　To investigate the impact of electrical impedance tomography (EIT) and the ARDSnet titration method for positive end-expiratory pressure (PEEP) on the short-term prognosis of moderate to severe acute respiratory distress syndrome (ARDS). Method　This study was a prospective investigation. A total of 100 patients with severe ARDS admitted to Xuzhou First People's Hospital from January 2022 to December 2023 were selected as study subjects. Patients were randomly assigned to the EIT group and the ARDSnet group using a computer-generated random number table, with 50 cases in each group. The EIT group included 30 males and 20 females, with an average age of (55.62±8.45) years and a body mass index (BMI) of (26.51±3.64) kg/m². The ARDSnet group included 28 males and 22 females, with an average age of (55.93±8.61) years and a BMI of (27.06±3.73) kg/m². Both groups received continuous invasive mechanical ventilation. The ARDSnet group set the PEEP value according to the oxygenation methods recommended by ARDSnet, aiming to maintain oxygen saturation (SpO₂) between 88%-95% and arterial oxygen partial pressure (PaO₂) between 55-80 mmHg. The EIT group underwent EIT measurements during the supine PEEP titration process, with EIT data recorded. Starting from an initial pressure of 5 cmH₂O, PEEP was gradually increased using an incremental method, raising it by 2 cmH₂O every 2 minutes until a plateau pressure of 30 cmH₂O was reached, ensuring it did not exceed this upper limit. Compare the levels of hemodynamics, pulmonary edema, arterial blood gas analysis, respiratory mechanics parameters, and treatment efficacy between two groups treated for 12 hours and on days 1, 2, 3, and 5. Statistical analysis was performed using χ² tests and t tests. Result　On day 5, the heart rate in the EIT group was lower, while the mean arterial pressure on days 3 and 5, and cardiac index, arterial oxygen partial pressure, oxygenation index, tidal volume, and compliance on days 2, 3, and 5 were higher than those in the ARDSnet group. At all-time points, extravascular lung water and the permeability index, flow rate, peak airway pressure, plateau airway pressure, transpulmonary pressure, and driving pressure on days 2, 3, and 5 were lower in the EIT group compared to the ARDSnet group, with statistically significant differences for all intergroup comparisons, time points, and interactions (all P<0.05). The 28-day mortality rate in the EIT group was 20.0% (10/50), while in the ARDSnet group it was 38.0% (19/50), with a statistically significant difference (χ²=3.934, P=0.047). The duration of invasive mechanical ventilation and the length of stay in the intensive care unit (ICU) were both shorter in the EIT group compared to the ARDSnet group [(14.25±5.63) d vs. (16.83±6.41) d, (21.52±8.76) d vs. (25.39±9.26) d], with statistically significant differences (all P<0.05). Conclusion　Severe ARDS patients are treated with EIT therapy, which effectively reduces mortality, shortens mechanical ventilation time, and ICU stay by improving lung compliance, reducing airway resistance, optimizing ventilation strategies, and implementing fine fluid management.

Key words: Acute respiratory distress syndrome, Severe, Electrical impedance tomography,  , Positive end-expiratory pressure,  , ADRSnet

摘要：

目的　探究电阻抗断层扫描（EIT）与ARDSnet滴定呼气末正压（PEEP）法对重度急性呼吸窘迫综合征（ARDS）短期预后的影响。方法　本研究为前瞻性研究。选取徐州市第一人民医院2022年1月至2023年12月期间收治的重度ARDS患者100例为研究对象，采用计算机生成的随机数字表法将患者分为EIT组和ARDSnet组，每组50例。EIT组中男30例、女20例，年龄（55.62±8.45）岁，体重指数（BMI）（26.51±3.64）kg/m²。ARDSnet组男28例、女22例，年龄（55.93±8.61）岁，BMI（27.06±3.73）kg/m²。两组患者均接受持续的有创机械通气治疗。ARDSnet组依据ARDSnet推荐的氧合法设定PEEP值，目标为维持血氧饱和度（SpO2）88%～95%、动脉血氧分压（PaO2）55～80 mmHg（1 mmHg=0.133 kPa）。EIT组进行EIT测量，在进行仰卧位PEEP滴定过程中记录EIT数据，在无自主呼吸的条件下，从5 cmH2O（1 cmH2O=0.098 kPa）初始压力开始，采用递增法逐步增加PEEP，每2 min提升2 cmH2O，直至平台压达到30 cmH2O，确保不超过此压力上限。比较两组治疗12 h和第1、2、3、5天的血流动力学、肺水肿、动脉血气分析、呼吸力学参数水平和治疗效果。统计分析采用χ2检验、t检验。结果　EIT组第5天心率较低，第3、5天平均动脉压和第2、3、5天心指数、动脉血氧分压、氧合指数、潮气量、顺应性均高于ARDSnet组，所有时间点血管外肺水和第2、3、5天血管通透性指数、流速、气道峰压、气道平台压、跨肺压、驱动压均低于ARDSnet组，上述指标组间、时间及交互比较，差异均有统计学意义（均P<0.05）。EIT组28 d病死率为20.0%（10/50），ARDSnet组为38.0%（19/50），差异有统计学意义（χ2=3.934，P=0.047）。EIT组有创机械通气时间、重症监护病房（ICU）住院时间均短于ARDSnet组［（14.25±5.63）d比（16.83±6.41）d、（21.52±8.76）d比（25.39±9.26）d），差异均有统计学意义（均P<0.05）。结论　重度ARDS患者采用EIT治疗方案，通过提升肺部顺应性、降低气道阻力、优化通气策略以及实施精细的液体管理，有效降低病死率，缩短机械通气时间和ICU住院天数。

关键词:

急性呼吸窘迫综合征, 重度, 电阻抗断层扫描, 呼气末正压, ARDSnet