There is a strong rationale for proposing transpulmonary pressure-guided protective ventilation in acute respiratory distress syndrome. The reference esophageal balloon catheter method requires complex in vivo calibration, expertise and specific material order. A simple, inexpensive, accurate and reproducible method of measuring esophageal pressure would greatly facilitate the measure of transpulmonary pressure to individualize protective ventilation in the intensive care unit. We propose an air-filled esophageal catheter method without balloon, using a disposable catheter that allows reproducible esophageal pressure measurements. We use a 49-cm-long 10 Fr thin suction catheter, positioned in the lower-third of the esophagus and connected to an air-filled disposable blood pressure transducer bound to the monitor and pressurized by an air-filled infusion bag. Only simple calibration by zeroing the transducer to atmospheric pressure and unit conversion from mmHg to cmH2O are required. We compared our method with the reference balloon catheter both ex vivo, using pressure chambers, and in vivo, in 15 consecutive mechanically ventilated patients. Esophageal-to-airway pressure change ratios during the dynamic occlusion test were close to one (1.03 ± 0.19 and 1.00 ± 0.16 in the controlled and assisted modes, respectively), validating the proper esophageal positioning. The Bland–Altman analysis revealed no bias of our method compared with the reference and good precision for inspiratory, expiratory and delta esophageal pressure measurements in both the controlled (largest bias −0.5 cmH2O [95% confidence interval: −0.9; −0.1] cmH2O; largest limits of agreement −3.5 to 2.5 cmH2O) and assisted modes (largest bias −0.3 [−2.6; 2.0] cmH2O). We observed a good repeatability (intra-observer, intraclass correlation coefficient, ICC: 0.89 [0.79; 0.96]) and reproducibility (inter-observer ICC: 0.89 [0.76; 0.96]) of esophageal measurements. The direct comparison with pleural pressure in two patients and spectral analysis by Fourier transform confirmed the reliability of the air-filled catheter-derived esophageal pressure as an accurate surrogate of pleural pressure. A calculator for transpulmonary pressures is available online. We propose a simple, minimally invasive, inexpensive and reproducible method for esophageal pressure monitoring with an air-filled esophageal catheter without balloon. It holds the promise of widespread bedside use of transpulmonary pressure-guided protective ventilation in ICU patients.

中文翻译：

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用充气食管导管测量跨肺压的新方法

在急性呼吸窘迫综合征中提出跨肺压力引导的保护性通气是有充分理由的。参考食管球囊导管方法需要复杂的体内校准、专业知识和特定的材料顺序。一种简单、廉价、准确和可重复的食道压力测量方法将极大地促进跨肺压测量，以实现重症监护病房的个体化保护性通气。我们提出了一种没有球囊的充气食管导管方法，使用一次性导管，可重复测量食管压力。我们使用一根 49 厘米长的 10 Fr 细吸管，位于食道的下三分之一处，并连接到一个充气的一次性血压传感器，该传感器绑定在监测器上，并由充气输液袋加压。只需要通过将传感器归零到大气压和单位从 mmHg 到 cmH2O 的简单校准。我们在 15 名连续机械通气患者中将我们的方法与参考球囊导管进行了体外、使用压力室和体内的比较。动态闭塞试验期间食管与气道压力变化比接近 1（在控制和辅助模式下分别为 1.03 ± 0.19 和 1.00 ± 0.16），验证了正确的食管定位。Bland-Altman 分析显示，与参考文献相比，我们的方法没有偏差，并且吸气精度良好，在受控（最大偏差 -0.5 cmH2O [95% 置信区间：-0.9; -0.1] cmH2O；最大一致性限制 -3.5 至 2.5 cmH2O）和辅助模式（最大偏差 -0.3 [- 2.6；2.0] cmH2O)。我们观察到食管测量具有良好的可重复性（观察者内、组内相关系数、ICC：0.89 [0.79; 0.96]）和可重复性（观察者间 ICC：0.89 [0.76; 0.96]）。与两名患者胸膜压力的直接比较和傅立叶变换的频谱分析证实了充气导管衍生的食管压力作为胸膜压力的准确替代指标的可靠性。跨肺压计算器可在线获取。我们提出了一种简单、微创、一种使用不带球囊的充气食管导管进行食管压力监测的廉价且可重复的方法。它有望在 ICU 患者中广泛使用床边跨肺压力引导的保护性通气。