■为了确定不同的呼气末正压(PEEP)对右心室功能的影响,血流动力学,氧合,以及中度至重度急性呼吸窘迫综合征(ARDS)患者中急性肺心病(ACP)的发生率。
■这项前瞻性配对设计研究涉及ICU中重度ARDS患者。参与者接受肺保护性通气和血流动力学监测。在研究期间,机械通气采用5cmH2O的PEEP,10cmH2O,和15cmH2O,同时保持吸气平台压力≤30cmH2O。各种评估,包括经胸超声心动图,心输出量测量,和血气分析,在基线和每次PEEP通气1小时后进行。随后,通气氧合的变化,超声心动图参数,分析不同PEEP下的血流动力学指标,探讨PEEP对右心室功能和血流动力学的潜在影响,以及ACP的发病率。
■共筛查了317名ARDS患者。其中,104符合中度至重度ARDS的诊断标准,52人完成了这项研究。这52名参与者的基线PEEP,在开工前获得的,为11.5±1.7cmH2O,ACP发生率为25.0%(13/52)。重症监护病房死亡率,整体医院死亡率,28天死亡率为19.2%(10/52),21.2%(11/52),和32.7%(17/52),分别。在研究期间,PEEP的ACP发生率为5cmH2O,10cmH2O,15cmH2O为17.3%(9/52),21.2%(11/52),和38.5%(20/52),分别。同时,PaO2/FiO2比值随PEEP的增加而提高,达到162.0(140.9,174.0),171.0(144.0,182.0),和176.5(151.0,196)mmHg的PEEP为5cmH2O,10cmH2O,和15cmH2O,分别。此外,较高的PEEP与PaCO2的轻微增加相关,与中等和低PEEP相比,差异有统计学意义.与5cmH2O或10cmH2O的PEEP相比,右心室功能在15cmH2OPEEP时表现出实质性变化,表现为肺动脉收缩压升高,右心室舒张末期面积增大,三尖瓣环平面收缩期偏移减少,都有显著的差异。相反,左心室舒张末期面积和射血分数的变化无统计学意义.在血液动力学方面,PEEP增加导致心脏指数(CI)下降,不同PEEP之间的差异具有统计学意义。具体来说,与PEEP为5cmH2O时的值相比,PEEP为15cmH2O时的CI下降了14.3%(2.63[2.20,2.95]与3.07[2.69,3.67],p<0.001)。每搏量指数随PEEP的下降更为明显(22.1[18.4,27.1]vs.27.0[24.2,33.0],p<0.001),达到18.1%。此外,随着PEEP的增加,舒张末期容积指数和血管外肺水指数均显著下降,而肺血管通透性指数未受影响。
■不同的PEEP可影响中重度ARDS患者ACP的发生率。高PEEP可改善氧合并减少血管外肺水,而不会显着影响肺血管通透性指数和左心室收缩功能。然而,会导致右心室扩张,以及右心室收缩功能和CI的大幅下降,从而导致ACP。
UNASSIGNED: To determine the effects of varying positive end-expiratory pressures (PEEPs) on right ventricular function, hemodynamics, oxygenation, and the incidence of acute cor pulmonale (ACP) in patients with moderate-to-severe acute respiratory distress syndrome (ARDS).
UNASSIGNED: This prospective paired-design study involved patients with moderate-to-severe ARDS in the ICU. Participants received lung-protective ventilation and hemodynamic monitoring. During the study, mechanical ventilation was administered with PEEPs of 5 cmH2O, 10 cmH2O, and 15 cmH2O, while maintaining an end-inspiratory plateau pressure ≤ 30 cmH2O. Various assessments, including transthoracic echocardiography, cardiac output measurement, and blood gas analysis, were conducted at baseline and after 1 h of ventilation at each PEEP. Subsequently, variations in ventilation oxygenation, echocardiographic parameters, and hemodynamic indicators under different PEEPs were analyzed to explore the potential effects of PEEP on right ventricular function and hemodynamics, as well as the incidence of ACP.
UNASSIGNED: A total of 317 ARDS patients were screened. Among them, 104 met the diagnostic criteria for moderate-to-severe ARDS, and 52 completed the study. The baseline PEEP of these 52 participants, acquired before commencement, was 11.5 ± 1.7 cmH2O, and the incidence of ACP was 25.0% (13/52). Intensive care unit mortality, overall hospital mortality, and 28-day mortality rates were 19.2% (10/52), 21.2% (11/52), and 32.7% (17/52), respectively. During the study, ACP incidences at PEEPs of 5 cmH2O, 10 cmH2O, and 15 cmH2O were 17.3% (9/52), 21.2% (11/52), and 38.5% (20/52), respectively. Meanwhile, the PaO2/FiO2 ratio improved with increasing PEEP, reaching 162.0 (140.9, 174.0), 171.0 (144.0, 182.0), and 176.5 (151.0, 196) mmHg at PEEPs of 5 cmH2O, 10 cmH2O, and 15 cmH2O, respectively. In addition, higher PEEPs were associated with a slight increase in PaCO2, showing statistically significant differences compared to moderate and low PEEPs. Compared to a PEEP of 5 cmH2O or 10 cmH2O, right ventricular function exhibited substantial changes at 15 cmH2O PEEP, manifested as increased pulmonary artery systolic pressure, enlarged right ventricular end-diastolic area, and decreased tricuspid annular plane systolic excursion, all with significant differences. Conversely, variations in left ventricular end-diastolic area and ejection fraction were not statistically significant. In terms of hemodynamics, increasing PEEP resulted in a decline in cardiac index (CI), with statistically significant differences between different PEEPs. Specifically, compared to the value at a PEEP of 5 cmH2O, the CI at a PEEP of 15 cmH2O decreased by 14.3% (2.63 [2.20, 2.95] vs. 3.07 [2.69, 3.67], p < 0.001). The decline in the stroke volume index with PEEP was more obvious (22.1 [18.4, 27.1] vs. 27.0 [24.2, 33.0], p < 0.001), reaching 18.1%. Additionally, both end-diastolic volume index and extravascular lung water index decreased significantly with increasing PEEP, while the pulmonary vascular permeability index remained unaffected.
UNASSIGNED: Different PEEPs can affect the incidence of ACP in patients with moderate-to-severe ARDS. High PEEP improves oxygenation and reduces extravascular lung water without significantly affecting the pulmonary vascular permeability index and left ventricular systolic function. Nevertheless, it can cause right ventricular dilation, as well as substantial declines in right ventricular systolic function and CI, thereby causing ACP.