Positive end expiratory pressure titrated by transpulmonary pressure improved oxygenation and respiratory mechanics in acute respiratory distress syndrome patients with intra‐abdominal hypertension

Background Intra‐abdominal hypertension (IAH) is common in acute respiratory distress syndrome (ARDS) patients and when resulting in decrease of chest wall compliance will weaken the effect of positive end expiratory pressure (PEEP). We investigated the effect of PEEP titrated by transpulmonary pressure (Ptp) on oxygenation and respiratory mechanics in ARDS patients with IAH compared with PEEP titrated by ARDSnet protocol. Methods ARDS patients admitted to the intensive care unit (ICU) of the Zhongda Hospital were enrolled. Patients were ventilated with volume control mode with tidal volume of 6 ml/kg under two different PEEP levels titrated by Ptp method and ARDSnet protocol. Respiratory mechanics, gas exchange and haemodynamics were measured after 30 minutes of ventilation in each round. IAH was defined as intra‐abdominal pressure of 12 mmHg or more. Results Seven ARDS patients with IAH and 8 ARDS patients without IAH were enrolled. PEEP titrated by Ptp were significant higher than PEEP titrated by ARDSnet protocol in both ARDS patients with IAH ((17.3±2.6) cmH2O vs. (6.3±1.6) cmH2O and without IAH ((9.5±2.1) cmH2O vs. (7.8±1.9) cmH2O). Arterial pressure of O2/fraction of inspired oxygen (PaO2/FiO2) was much higher under PEEP titrated by Ptp when compared with PEEP titrated by ARDSnet protocol in ARDS patients with IAH ((27.2±4.0) cmHg vs. (20.9± 5.0) cmHg. But no significant difference of PaO2/FiO2 between the two methods was found in ARDS patients without IAH. In ARDS patients with IAH, static compliance of lung and respiratory system were higher under PEEP titrated by Ptp than by ARDSnet protocol. In ARDS patients with IAH, central venous pressure (CVP) was higher during PEEP titrated by Ptp than by ARDSnet protocol. Conclusion Positive end expiratory pressure titrated by transpulmonary pressure was higher than PEEP titrated by ARDSnet protocol and improved oxygenation and respiratory mechanics in ARDS patients with IAH.

背景 腹腔内高压（IAH）在急性呼吸窘迫综合征（ARDS）患者中很常见，当导致胸壁顺应性降低时，会削弱呼气末正压（PEEP）的效果。我们研究了通过跨肺压（Ptp）滴定的PEEP与通过ARDSnet方案滴定的PEEP相比，对伴有IAH的ARDS患者的氧合和呼吸力学的影响。 方法 招募入住中大医院重症监护病房（ICU）的ARDS患者。患者采用容量控制模式通气，潮气量为6 ml/kg，分别在通过Ptp方法和ARDSnet方案滴定的两种不同PEEP水平下进行。每轮通气30分钟后测量呼吸力学、气体交换和血流动力学。IAH定义为腹腔内压为12 mmHg或更高。 结果 招募了7例伴有IAH的ARDS患者和8例不伴有IAH的ARDS患者。在伴有IAH的ARDS患者中，通过Ptp滴定的PEEP显著高于通过ARDSnet方案滴定的PEEP[（17.3±2.6）cmH₂O对（6.3±1.6）cmH₂O]，在不伴有IAH的ARDS患者中也是如此[（9.5±2.1）cmH₂O对（7.8±1.9）cmH₂O]。在伴有IAH的ARDS患者中，与通过ARDSnet方案滴定的PEEP相比，通过Ptp滴定的PEEP下动脉血氧分压/吸入氧分数（PaO₂/FiO₂）高得多[（27.2±4.0）cmHg对（20.9±5.0）cmHg]。但在不伴有IAH的ARDS患者中，两种方法之间PaO₂/FiO₂无显著差异。在伴有IAH的ARDS患者中，通过Ptp滴定的PEEP下肺和呼吸系统的静态顺应性高于通过ARDSnet方案滴定的PEEP。在伴有IAH的ARDS患者中，通过Ptp滴定PEEP时中心静脉压（CVP）高于通过ARDSnet方案滴定PEEP时。 结论 通过跨肺压滴定的呼气末正压高于通过ARDSnet方案滴定的PEEP，并改善了伴有IAH的ARDS患者的氧合和呼吸力学。