Department of Pulmonology Medicine, Division of Intensive Care, Trakya University Faculty of Medicine, Edirne, Türkiye.
Department of Anaesthesiology, Division of Intensive Care, Atatürk State Hospital, Turkish Ministry of Health, Aydın, Türkiye.
Niger J Clin Pract. 2024 Aug 1;27(8):1033-1037. doi: 10.4103/njcp.njcp_103_24. Epub 2024 Aug 26.
Positive end-expiratory pressure (PEEP) is a crucial component of mechanical ventilation to improve oxygenation in critically ill patients with respiratory failure. The interaction between abdominal and thoracic compartment pressures is known well. Especially in intra-abdominal hypertension, lower PEEP may cause atelectotrauma by repetitive opening and closing of alveoli.
In this study, it was aimed to investigate the effect of PEEP adjustment according to the intra-abdominal pressure (IAP) on oxygenation and clarify possible harms.
Patients older than 18 were mechanically ventilated due to hypoxemic respiratory failure and had normal IAP (<15 mmHg) included in the study. Patients with severe cardiovascular dysfunction were excluded. The following PEEP levels were applied: PEEPzero of 0 cmH2O, PEEPIAP/2 = 50% of IAP, and PEEPIAP = 100% of IAP. After a 30-minute equilibration period, arterial blood gases and mean arterial pressures were measured.
One hundred thirty-eight patients (mean age 66.5 ± 15.9, 56.5% male) enrolled on the study. The mean IAP was 9.8 ± 3.4. Seventy-nine percent of the patients' PaO2/FiO2 ratio was under 300 mmHg. Figure 1 shows the change in PaO2/FiO2 ratio, PaCO2, PPlato, and MAP of the patients according to the PEEP levels. Overall increases were detected in the PaO2/FiO2 ratio (P < 0.001) and Pplato (P < 0.001), while PaCO2 and MAP did not change after increasing PEEP gradually. Pairwise analyses revealed differences in PaO2/FiO2 between PEEPzero (186.4 [85.7-265.8]) and PEEPIAP/2 (207.7 [101.7-292.9]) (t = -0.77, P < 0.001), between baseline and PEEPIAP (236.1 [121.4-351.0]) (t = -1.7, P < 0.001), and between PEEPIAP/2 and PEEPIAP (t = -1.0, P < 0.001). Plato pressures were in the safe range (<30 cmH2O) at all three PEEP levels (PEEPzero = 12 [10-15], PEEPIAP/2 = 15 [13-18], PEEPIAP = 17 [14-22]).
In patients with acute hypoxemic respiratory failure and mechanically ventilated, PEEP adjustment according to the IAB improves oxygenation, especially in the settings of the limited source where other PEEP titration methods are absent.
在机械通气中，呼气末正压（PEEP）是改善呼吸衰竭危重症患者氧合的关键组成部分。腹部和胸腔压力之间的相互作用已得到充分证实。特别是在腹内高压时，较低的 PEEP 可能会通过肺泡的反复开闭导致肺泡萎陷伤。
本研究旨在探讨根据腹内压（IAP）调整 PEEP 对氧合的影响，并阐明可能的危害。
纳入因低氧性呼吸衰竭而接受机械通气且 IAP 正常（<15mmHg）的 18 岁以上患者。排除严重心血管功能障碍的患者。应用以下 PEEP 水平：PEEPzero 为 0cmH2O、PEEPIAP/2 = IAP 的 50%、PEEPIAP = IAP 的 100%。在 30 分钟的平衡期后，测量动脉血气和平均动脉压。
共纳入 138 例患者（平均年龄 66.5±15.9 岁，56.5%为男性）。IAP 的平均值为 9.8±3.4mmHg。79%的患者 PaO2/FiO2 比值<300mmHg。图 1 显示了根据 PEEP 水平患者 PaO2/FiO2 比值、PaCO2、PPlato 和 MAP 的变化。逐渐增加 PEEP 后，PaO2/FiO2 比值（P<0.001）和 Pplato（P<0.001）均有升高，而 PaCO2 和 MAP 则无变化。两两分析显示，PEEPzero（186.4[85.7-265.8]）与 PEEPIAP/2（207.7[101.7-292.9]）（t=-0.77，P<0.001）、基础值与 PEEPIAP（236.1[121.4-351.0]）（t=-1.7，P<0.001）以及 PEEPIAP/2 与 PEEPIAP（t=-1.0，P<0.001）之间的 PaO2/FiO2 比值存在差异。在所有三种 PEEP 水平（PEEPzero=12[10-15]、PEEPIAP/2=15[13-18]、PEEPIAP=17[14-22]）下，Plato 压力均处于安全范围（<30cmH2O）。
在急性低氧性呼吸衰竭并接受机械通气的患者中，根据 IAB 调整 PEEP 可改善氧合，尤其是在没有其他 PEEP 滴定方法的有限资源环境下。
