Effects of positive end-expiratory pressure alone or an open-lung approach on recruited lung volumes and respiratory mechanics of mechanically ventilated horses

2019 ◽  
Vol 46 (6) ◽  
pp. 780-788
Author(s):  
Joaquin D. Araos ◽  
Luca Lacitignola ◽  
Tania Stripoli ◽  
Salvatore Grasso ◽  
Antonio Crovace ◽  
...  
Keyword(s):  
Respiratory Mechanics ◽  
Positive End Expiratory Pressure ◽  
Lung Volumes ◽  
Mechanically Ventilated ◽  
Open Lung ◽  
Open Lung Approach

Physiological Effects of the Open Lung Approach in Patients with Early, Mild, Diffuse Acute Respiratory Distress Syndrome

2015 ◽  
Vol 123 (5) ◽  
pp. 1113-1121 ◽  
Author(s):  
Gilda Cinnella ◽  
Salvatore Grasso ◽  
Pasquale Raimondo ◽  
Davide D’Antini ◽  
Lucia Mirabella ◽  
...  
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Tidal Volume ◽  
Distress Syndrome ◽  
Driving Pressure ◽  
Lung Mechanics ◽  
Positive End Expiratory Pressure ◽  
Open Lung ◽  
Open Lung Approach

Abstract Background To test the hypothesis that in early, mild, acute respiratory distress syndrome (ARDS) patients with diffuse loss of aeration, the application of the open lung approach (OLA) would improve homogeneity in lung aeration and lung mechanics, without affecting hemodynamics. Methods Patients were ventilated according to the ARDS Network protocol at baseline (pre-OLA). OLA consisted in a recruitment maneuver followed by a decremental positive end-expiratory pressure trial. Respiratory mechanics, gas exchange, electrical impedance tomography (EIT), cardiac index, and stroke volume variation were measured at baseline and 20 min after OLA implementation (post-OLA). Esophageal pressure was used for lung and chest wall elastance partitioning. The tomographic lung image obtained at the fifth intercostal space by EIT was divided in two ventral and two dorsal regions of interest (ROIventral and ROIDorsal). Results Fifteen consecutive patients were studied. The OLA increased arterial oxygen partial pressure/inspired oxygen fraction from 216 ± 13 to 311 ± 19 mmHg (P < 0.001) and decreased elastance of the respiratory system from 29.4 ± 3 cm H2O/l to 23.6 ± 1.7 cm H2O/l (P < 0.01). The driving pressure (airway opening plateau pressure − total positive end-expiratory pressure) decreased from 17.9 ± 1.5 cm H2O pre-OLA to 15.4 ± 2.1 post-OLA (P < 0.05). The tidal volume fraction reaching the dorsal ROIs increased, and consequently the ROIVentral/Dorsal impedance tidal variation decreased from 2.01 ± 0.36 to 1.19 ± 0.1 (P < 0.01). Conclusions The OLA decreases the driving pressure and improves the oxygenation and lung mechanics in patients with early, mild, diffuse ARDS. EIT is useful to assess the impact of OLA on regional tidal volume distribution.

scholarly journals Nonlinearity of respiratory mechanics during bronchoconstriction in mice with airway inflammation

2002 ◽  
Vol 92 (5) ◽  
pp. 1802-1807 ◽  
Author(s):  
Scott Wagers ◽  
Lennart Lundblad ◽  
Henrique T. Moriya ◽  
Jason H. T. Bates ◽  
Charles G. Irvin
Keyword(s):  
Respiratory System ◽  
Lung Volume ◽  
Respiratory Mechanics ◽  
Equation Of Motion ◽  
Model Fit ◽  
Airway Closure ◽  
Lung Volumes ◽  
Mechanically Ventilated ◽  
Respiratory System Resistance ◽  
The Impact

Respiratory system resistance (R) and elastance (E) are commonly estimated by fitting the linear equation of motion P = EV + RV˙ + P0 ( Eq. 1 ) to measurements of respiratory pressure (P), lung volume (V), and flow (V˙). However, the respiratory system is unlikely to behave linearly under many circumstances. We determined the importance of respiratory system nonlinearities in two groups of mechanically ventilated Balb/c mice [controls and mice with allergically inflamed airways (ova/ova)], by assessing the impact of the addition of nonlinear terms (E2V2 and R2V˙‖V˙‖) on the goodness of model fit seen with Eq. 1 . Significant improvement in fit (51.85 ± 4.19%) was only seen in the ova/ova mice during bronchoconstriction when the E2V2alone was added. An improvement was also observed with addition of the E2V2 term in mice with both low and high lung volumes ventilated at baseline, suggesting a volume-dependent nonlinearity of E. We speculate that airway closure in the constricted ova/ova mice accentuated the volume-dependent nonlinearity by decreasing lung volume and overdistending the remaining lung.

scholarly journals Effects of Positive End-Expiratory Pressure on Lung Recruitment, Respiratory Mechanics, and Intracranial Pressure in Mechanically Ventilated Brain-Injured Patients

2021 ◽  
Vol 12 ◽  
Author(s):  
Chiara Robba ◽  
Lorenzo Ball ◽  
Stefano Nogas ◽  
Denise Battaglini ◽  
Antonio Messina ◽  
...  
Keyword(s):  
Brain Injury ◽  
Intracranial Pressure ◽  
Respiratory Mechanics ◽  
Lung Recruitment ◽  
Positive End Expiratory Pressure ◽  
Mechanically Ventilated ◽  
Brain Injured ◽  
Injured Patients ◽  
Lung Ct ◽  
Increased Icp

Background: The pathophysiological effects of positive end-expiratory pressure (PEEP) on respiratory mechanics, lung recruitment, and intracranial pressure (ICP) in acute brain-injured patients have not been completely elucidated. The primary aim of this study was to assess the effects of PEEP augmentation on respiratory mechanics, quantitative computed lung tomography (qCT) findings, and its relationship with ICP modifications. Secondary aims included the assessment of the correlations between different factors (respiratory mechanics and qCT features) with the changes of ICP and how these factors at baseline may predict ICP response after greater PEEP levels.Methods: A prospective, observational study included mechanically ventilated patients with acute brain injury requiring invasive ICP and who underwent two-PEEP levels lung CT scan. Respiratory system compliance (Crs), arterial partial pressure of carbon dioxide (PaCO2), mean arterial pressure (MAP), data from qCT and ICP were obtained at PEEP 5 and 15 cmH2O.Results: Sixteen examinations (double PEEP lung CT and neuromonitoring) in 15 patients were analyzed. The median age of the patients was 54 years (interquartile range, IQR = 39–65) and 53% were men. The median Glasgow Coma Scale (GCS) at intensive care unit (ICU) admission was 8 (IQR = 3–12). Median alveolar recruitment was 2.5% of total lung weight (−1.5 to 4.7). PEEP from 5 to 15 cmH2O increased ICP [median values from 14.0 (11.2–17.5) to 23.5 (19.5–26.8) mmHg, p < 0.001, respectively]. The amount of recruited lung tissue on CT was inversely correlated with the change (Δ) in ICP (rho = −0.78; p = 0.0006). Additionally, ΔCrs (rho = −0.77, p = 0.008), ΔPaCO2 (rho = 0.81, p = 0.0003), and ΔMAP (rho = −0.64, p = 0.009) were correlated with ΔICP. Baseline Crs was not predictive of ICP response to PEEP.Conclusions: The main factors associated with increased ICP after PEEP augmentation included reduced Crs, lower MAP and lung recruitment, and increased PaCO2, but none of these factors was able to predict, at baseline, ICP response to PEEP. To assess the potential benefits of increased PEEP in patients with acute brain injury, hemodynamic status, respiratory mechanics, and lung morphology should be taken into account.

Auto-PEEP effects on respiratory mechanics and blood gases in mechanically ventilated patients

1998 ◽  
Vol 74 (4) ◽  
pp. 275-83
Author(s):  
Antônio C. P. Ferreira ◽  
Benjamin I. Kopelman ◽  
Werther Brunow de Carvalho ◽  
Jorge Bonassa
Keyword(s):  
Respiratory Mechanics ◽  
Blood Gases ◽  
Mechanically Ventilated ◽  
Mechanically Ventilated Patients ◽  
Ventilated Patients

scholarly journals Effect of pressure-controlled ventilation-volume guaranteed mode combined with individualized positive end-expiratory pressure on respiratory mechanics, oxygenation and lung injury in patients undergoing laparoscopic surgery in Trendelenburg position

2021 ◽  
Author(s):  
Jianli Li ◽  
Saixian Ma ◽  
Xiujie Chang ◽  
Songxu Ju ◽  
Meng Zhang ◽  
...  
Keyword(s):  
Laparoscopic Surgery ◽  
Lung Injury ◽  
Respiratory Mechanics ◽  
Lung Mechanics ◽  
Trial Registry ◽  
Positive End Expiratory Pressure ◽  
Clinical Trial Registry ◽  
Trendelenburg Position ◽  
Pressure Controlled Ventilation ◽  
Pressure Controlled

AbstractThe study aimed to investigate the efficacy of PCV-VG combined with individual PEEP during laparoscopic surgery in the Trendelenburg position. 120 patients were randomly divided into four groups: VF group (VCV plus 5cmH2O PEEP), PF group (PCV-VG plus 5cmH2O PEEP), VI group (VCV plus individual PEEP), and PI group (PCV-VG plus individual PEEP). Pmean, Ppeak, Cdyn, PaO2/FiO2, VD/VT, A-aDO2 and Qs/Qt were recorded at T1 (15 min after the induction of anesthesia), T2 (60 min after pneumoperitoneum), and T3 (5 min at the end of anesthesia). The CC16 and IL-6 were measured at T1 and T3. Our results showed that the Pmean was increased in VI and PI group, and the Ppeak was lower in PI group at T2. At T2 and T3, the Cdyn of PI group was higher than that in other groups, and PaO2/FiO2 was increased in PI group compared with VF and VI group. At T2 and T3, A-aDO2 of PI and PF group was reduced than that in other groups. The Qs/Qt was decreased in PI group compared with VF and VI group at T2 and T3. At T2, VD/VT in PI group was decreased than other groups. At T3, the concentration of CC16 in PI group was lower compared with other groups, and IL-6 level of PI group was decreased than that in VF and VI group. In conclusion, the patients who underwent laparoscopic surgery, PCV-VG combined with individual PEEP produced favorable lung mechanics and oxygenation, and thus reducing inflammatory response and lung injury.Clinical Trial registry: chictr.org. identifier: ChiCTR-2100044928

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