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Updated: Aug 19, 2026

Normothermic Negative Pressure Ventilation Ex Situ Lung Perfusion: Evaluation of Lung Function and Metabolism
Published on: February 14, 2022
Effects of positive end-expiratory pressure on ventilatory and oxygenation parameters during pressure-controlled
N Mert Sentürk1, Ahmet Dilek, Emre Camci
1Department of Anaesthesiology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey. senturkem@superonline.com
Objectives:
The purpose of this study was to investigate the effects of PEEP on oxygenation and airway pressures during PCV-OLV.
Design:
Randomized, crossover, clinical study.
Setting:
University hospital.
Participants:
Twenty-five patients undergoing thoracotomy.
Interventions:
During the first 5 minutes of OLV, all patients were ventilated with VCV (PEEP: 0) (VCV-ZEEP). Afterward, ventilation was changed to PCV with PEEP: 0 (PCV-ZEEP) or PEEP: 4 cmH2O (PCV-PEEP) for 20 minutes. In the following 20 minutes, PCV-PEEP and PCV-ZEEP were applied in reverse sequence.
Measurements And Main Results:
At the end of VCV-ZEEP airway pressures (peak airway pressure, plateau airway pressure, mean airway pressure, and pause airway pressure) were recorded. At the end of PCV-PEEP and PCV-ZEEP airway pressures, PaO2 and Qs/Qt were recorded. Ppeak and Pplat were significantly lower with PCV-PEEP compared with VCV-ZEEP (eg, Ppeak: 33.4+/-4.2, 28.3+/-4.1, and 28.9+/-3.7 cmH2O in VCV-ZEEP, PCV-ZEEP, and PCV-PEEP, respectively; p<0.05 for PCV-ZEEP v VCV-ZEEP and PCV-PEEP v VCV-ZEEP). PCV-PEEP was associated with an increased PaO2 (230.3+/-69.8 v 189.0+/-54.8 mmHg, p<0.05) and decreased Qs/Qt (33.4%+/-7.3% v 38.4%+/-5.7%, p<0.05) compared with PCV-ZEEP (mean+/-SD). Eighty-eight percent of the patients have benefited from PEEP.
Conclusion:
During OLV, PCV with a low level of PEEP leads to improved oxygenation with lower airway pressures.
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