Related Experiment Video
Updated: Nov 6, 2025
Ex Vivo Porcine Experimental Model for Studying and Teaching Lung Mechanics
Published on: April 19, 2024
Effects of two stepwise lung recruitment strategies on respiratory function and haemodynamics in anaesthetised pigs:
Jakob Wittenstein1, Robert Huhle, Martin Scharffenberg
1From 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).
Background:
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.
Objectives:
To compare the effects of the PROVHILO strategy and the iPROVE strategy on respiratory and haemodynamic variables.
Design:
Randomised crossover study.
Setting:
University hospital research facility.
Animals:
A total of 20 juvenile anaesthetised pigs.
Interventions:
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).
Main Outcome Measures:
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.
Results:
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.
Conclusion:
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.
Trial Registration:
This study was registered and approved by the Landesdirektion Dresden, Germany (DD24-5131/338/28).
More Related Videos
08:58Development of a Neonatal Piglet Acute Lung Injury Model Recreating the Early Environment of Preterm Infant Lungs
Published on: October 31, 2025
06:22Surfactant Depletion Combined with Injurious Ventilation Results in a Reproducible Model of the Acute Respiratory Distress Syndrome ARDS
Published on: April 7, 2021