From the Department of Anaesthesiology and Intensive Care Medicine, Pulmonary Engineering Group, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany (JW, RH, MS, TK, JH, LV, AB, MGdeA, TB), Department of Pathophysiology and Transplantation, University of Milan, Milan (LV), San Martino Hospital, IRCCS for Oncology, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy (AB, PP), Department of Intensive Care and Laboratory of Experimental Intensive Care and Anaesthesiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (MJS), Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy (PP) and Outcomes Research Consortium, Cleveland, Ohio, USA (MGdeA).
Eur J Anaesthesiol. 2021 Jun 1;38(6):634-643. doi: 10.1097/EJA.0000000000001480.
Lung recruitment manoeuvres and positive end-expiratory pressure (PEEP) can improve lung function during general anaesthesia. Different recruitment manoeuvre strategies have been described in large international trials: in the protective ventilation using high vs. low PEEP (PROVHILO) strategy, tidal volume (VT) was increased during volume-controlled ventilation; in the individualised peri-operative open-lung approach vs. standard protective ventilation in abdominal surgery (iPROVE) strategy, PEEP was increased during pressure-controlled ventilation.
To compare the effects of the PROVHILO strategy and the iPROVE strategy on respiratory and haemodynamic variables.
Randomised crossover study.
University hospital research facility.
A total of 20 juvenile anaesthetised pigs.
Animals were assigned randomly to one of two sequences: PROVHILO strategy followed by iPROVE strategy or vice-versa (n = 10/sequence). In the PROVHILO strategy, VT was increased stepwise by 4 ml kg-1 at a fixed PEEP of 12 cmH2O until a plateau pressure of 30 to 35 cmH2O was reached. In the iPROVE strategy, at fixed driving pressure of 20 cmH2O, PEEP was increased up to 20 cmH2O followed by PEEP titration according to the lowest elastance of the respiratory system (ERS).
We assessed regional transpulmonary pressure (Ptrans), respiratory system mechanics, gas exchange and haemodynamics, as well as the centre of ventilation (CoV) by electrical impedance tomography.
During recruitment manoeuvres with the PROVHILO strategy compared with the iPROV strategy, dorsal Ptrans was lower at end-inspiration (16.3 ± 2.7 vs. 18.6 ± 3.1 cmH2O, P = 0.001) and end-expiration (4.8 ± 2.6 vs. 8.8 ± 3.4 cmH2O, P < 0.001), and mean arterial pressure (MAP) was higher (77 ± 11 vs. 60 ± 14 mmHg, P < 0.001). At 1 and 15 min after recruitment manoeuvres, ERS was higher in the PROVHILO strategy than the iPROVE strategy (24.6 ± 3.9 vs. 21.5 ± 3.4 and 26.7 ± 4.3 vs. 24.0 ± 3.8 cmH2O l-1; P < 0.001, respectively). At 1 min, PaO2 was lower in PROVHILO compared with iPROVE strategy (57.1 ± 6.1 vs. 59.3 ± 5.1 kPa, P = 0.013), but at 15 min, values did not differ. CoV did not differ between strategies.
In anaesthetised pigs, the iPROVE strategy compared with the PROVHILO strategy increased dorsal Ptrans at the cost of lower MAP during recruitment manoeuvres, and decreased ERS thereafter, without consistent improvement of oxygenation or shift of the CoV.
This study was registered and approved by the Landesdirektion Dresden, Germany (DD24-5131/338/28).
在全身麻醉期间，肺复张手法和呼气末正压（PEEP）可以改善肺功能。在大型国际试验中已经描述了不同的募集策略：在保护性通气使用高 vs. 低 PEEP（PROVHILO）策略中，在容量控制通气期间增加潮气量（VT）；在个体化围手术期开肺法与腹部手术中的标准保护性通气（iPROVE）策略中，在压力控制通气期间增加 PEEP。
比较 PROVHILO 策略和 iPROVE 策略对呼吸和血流动力学变量的影响。
随机交叉研究。
大学医院研究设施。
总共 20 头麻醉的幼年猪。
动物随机分为两组之一：PROVHILO 策略 followed by iPROVE 策略或反之（n=10/sequence）。在 PROVHILO 策略中，以 4ml/kg 的增量逐步增加 VT，同时保持 12cmH2O 的固定 PEEP，直到达到 30 到 35cmH2O 的平台压力。在 iPROVE 策略中，在固定驱动压力为 20cmH2O 的情况下，增加 PEEP 至 20cmH2O，然后根据呼吸系统最低顺应性（ERS）进行 PEEP 滴定。
我们评估了区域跨肺压（Ptrans）、呼吸系统力学、气体交换和血流动力学，以及通过电阻抗断层成像术评估通气中心（CoV）。
与 iPROV 策略相比，在 PROVHILO 策略的募集手法中，吸气末和呼气末的背侧 Ptrans 较低（分别为 16.3±2.7 与 18.6±3.1cmH2O，P=0.001；4.8±2.6 与 8.8±3.4cmH2O，P<0.001），平均动脉压（MAP）较高（77±11 与 60±14mmHg，P<0.001）。在募集手法后 1 和 15 分钟，PROVHILO 策略的 ERS 高于 iPROVE 策略（分别为 24.6±3.9、21.5±3.4 和 26.7±4.3 与 24.0±3.8cmH2O l-1；P<0.001）。在 1 分钟时，PROVHILO 与 iPROVE 策略相比，PaO2 较低（分别为 57.1±6.1 与 59.3±5.1kPa，P=0.013），但在 15 分钟时，两者没有差异。CoV 在两种策略之间没有差异。
在麻醉猪中，与 PROVHILO 策略相比，iPROVE 策略在募集手法期间增加了背侧 Ptrans，但以较低的 MAP 为代价，并且此后 ERS 降低，而氧合或 CoV 没有明显改善。
本研究已在德国德累斯顿地区（DD24-5131/338/28）注册并获得批准。
