Open AccessMechanical power thresholds during mechanical ventilation: An experimental study
Author(s) -
Romitti Federica,
Busana Mattia,
Palumbo Maria Michela,
Bonifazi Matteo,
Giosa Lorenzo,
Vassalli Francesco,
Gatta Alessandro,
Collino Francesca,
Steinberg Irene,
Gattarello Simone,
Lazzari Stefano,
Palermo Paola,
Nasr Ahmed,
Gersmann AnnKathrin,
Richter Annika,
Herrmann Peter,
Moerer Onnen,
Saager Leif,
Camporota Luigi,
Marini John J.,
Quintel Michael,
Meissner Konrad,
Gattii Luciano
Publication year - 2022
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.15225
Subject(s) - mechanical ventilation , ventilation (architecture) , medicine , lung , respiratory system , elastance , functional residual capacity , strain (injury) , perfusion , respiration , anesthesia , zoology , cardiology , lung volumes , biology , anatomy , physics , thermodynamics
Abstract The extent of ventilator‐induced lung injury may be related to the intensity of mechanical ventilation––expressed as mechanical power. In the present study, we investigated whether there is a safe threshold, below which lung damage is absent. Three groups of six healthy pigs (29.5 ± 2.5 kg) were ventilated prone for 48 h at mechanical power of 3, 7, or 12 J/min. Strain never exceeded 1.0. PEEP was set at 4 cmH 2 O. Lung volumes were measured every 12 h; respiratory, hemodynamics, and gas exchange variables every 6. End‐experiment histological findings were compared with a control group of eight pigs which did not undergo mechanical ventilation. Functional residual capacity decreased by 10.4% ± 10.6% and 8.1% ± 12.1% in the 7 J and 12 J groups ( p = 0.017, p < 0.001) but not in the 3 J group (+1.7% ± 17.7%, p = 0.941). In 3 J group, lung elastance, PaO 2 and PaCO 2 were worse compared to 7 J and 12 J groups (all p < 0.001), due to lower ventilation‐perfusion ratio (0.54 ± 0.13, 1.00 ± 0.25, 1.78 ± 0.36 respectively, p < 0.001). The lung weight was lower ( p < 0.001) in the controls (6.56 ± 0.90 g/kg) compared to 3, 7, and 12 J groups (12.9 ± 3.0, 16.5 ± 2.9, and 15.0 ± 4.1 g/kg, respectively). The wet‐to‐dry ratio was 5.38 ± 0.26 in controls, 5.73 ± 0.52 in 3 J, 5.99 ± 0.38 in 7 J, and 6.13 ± 0.59 in 12 J group ( p = 0.03). Vascular congestion was more extensive in the 7 J and 12 J compared to 3 J and control groups. Mechanical ventilation (with anesthesia/paralysis) increase lung weight, and worsen lung histology, regardless of the mechanical power. Ventilating at 3 J/min led to better anatomical variables than at 7 and 12 J/min but worsened the physiological values.