scholarly journals Regional tidal lung strain in mechanically ventilated normal lungs

2016 ◽  
Vol 121 (6) ◽  
pp. 1335-1347 ◽  
Author(s):  
Luis Felipe Paula ◽  
Tyler J. Wellman ◽  
Tilo Winkler ◽  
Peter M. Spieth ◽  
Andreas Güldner ◽  
...  
Keyword(s):  
Lung Injury ◽  
Tidal Volume ◽  
Lung Volume ◽  
Mechanically Ventilated ◽  
Reference Volume ◽  
Ventilator Induced Lung Injury ◽  
Vertical Heterogeneity ◽  
Dorsal Axis ◽  
Lung Strain ◽  
Normal Lungs

Parenchymal strain is a key determinant of lung injury produced by mechanical ventilation. However, imaging estimates of volumetric tidal strain (ε = regional tidal volume/reference volume) present substantial conceptual differences in reference volume computation and consideration of tidally recruited lung. We compared current and new methods to estimate tidal volumetric strains with computed tomography, and quantified the effect of tidal volume (VT) and positive end-expiratory pressure (PEEP) on strain estimates. Eight supine pigs were ventilated with VT = 6 and 12 ml/kg and PEEP = 0, 6, and 12 cmH2O. End-expiratory and end-inspiratory scans were analyzed in eight regions of interest along the ventral-dorsal axis. Regional reference volumes were computed at end-expiration (with/without correction of regional VT for intratidal recruitment) and at resting lung volume (PEEP = 0) corrected for intratidal and PEEP-derived recruitment. All strain estimates demonstrated vertical heterogeneity with the largest tidal strains in middependent regions ( P < 0.01). Maximal strains for distinct estimates occurred at different lung regions and were differently affected by VT-PEEP conditions. Values consistent with lung injury and inflammation were reached regionally, even when global measurements were below critical levels. Strains increased with VT and were larger in middependent than in nondependent lung regions. PEEP reduced tidal-strain estimates referenced to end-expiratory lung volumes, although it did not affect strains referenced to resting lung volume. These estimates of tidal strains in normal lungs point to middependent lung regions as those at risk for ventilator-induced lung injury. The different conditions and topography at which maximal strain estimates occur allow for testing the importance of each estimate for lung injury.

Linking lung function and inflammatory responses in ventilator-induced lung injury

2011 ◽  
Vol 300 (1) ◽  
pp. L112-L120 ◽  
Author(s):  
Vincenzo Cannizzaro ◽  
Zoltan Hantos ◽  
Peter D. Sly ◽  
Graeme R. Zosky
Keyword(s):  
Lung Function ◽  
Lung Injury ◽  
Tidal Volume ◽  
Lung Volume ◽  
Inflammatory Responses ◽  
Lung Mechanics ◽  
Forced Oscillation Technique ◽  
Ventilation Strategy ◽  
Ventilator Induced Lung Injury ◽  
Tnf Α

Despite decades of research, the mechanisms of ventilator-induced lung injury are poorly understood. We used strain-dependent responses to mechanical ventilation in mice to identify associations between mechanical and inflammatory responses in the lung. BALB/c, C57BL/6, and 129/Sv mice were ventilated using a protective [low tidal volume and moderate positive end-expiratory pressure (PEEP) and recruitment maneuvers] or injurious (high tidal volume and zero PEEP) ventilation strategy. Lung mechanics and lung volume were monitored using the forced oscillation technique and plethysmography, respectively. Inflammation was assessed by measuring numbers of inflammatory cells, cytokine (IL-6, IL-1β, and TNF-α) levels, and protein content of the BAL. Principal components factor analysis was used to identify independent associations between lung function and inflammation. Mechanical and inflammatory responses in the lung were dependent on ventilation strategy and mouse strain. Three factors were identified linking 1) pulmonary edema, protein leak, and macrophages, 2) atelectasis, IL-6, and TNF-α, and 3) IL-1β and neutrophils, which were independent of responses in lung mechanics. This approach has allowed us to identify specific inflammatory responses that are independently associated with overstretch of the lung parenchyma and loss of lung volume. These data provide critical insight into the mechanical responses in the lung that drive local inflammation in ventilator-induced lung injury and the basis for future mechanistic studies in this field.

scholarly journals Interaction between regional lung volumes and ventilator-induced lung injury in the normal and endotoxemic lung

2020 ◽  
Vol 318 (3) ◽  
pp. L494-L499 ◽  
Author(s):  
Seiha Yen ◽  
Melissa Preissner ◽  
Ellen Bennett ◽  
Stephen Dubsky ◽  
Richard Carnibella ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Lung Injury ◽  
Tidal Volume ◽  
Lung Volumes ◽  
Mechanically Ventilated ◽  
Ventilator Induced Lung Injury ◽  
Computed Tomography Images ◽  
Gas Trapping ◽  
Regional Lung ◽  
The Relationship

Both overdistension and atelectasis contribute to lung injury and mortality during mechanical ventilation. It has been proposed that combinations of tidal volume and end-expiratory lung volume exist that minimize lung injury linked to mechanical ventilation. The aim of this study was to examine this at the regional level in the healthy and endotoxemic lung. Adult female BALB/c mice were injected intraperitoneally with 10 mg/kg lipopolysaccharide (LPS) in saline or with saline alone. Four hours later, mice were mechanically ventilated for 2 h. Regional specific end-expiratory volume (sEEV) and tidal volume (sVt) were measured at baseline and after 2 h of ventilation using dynamic high-resolution four-dimensional computed tomography images. The regional expression of inflammatory genes was quantified by quantitative PCR. There was a heterogenous response in regional sEEV whereby endotoxemia increased gas trapping at end-expiration in some lung regions. Within the healthy group, there was a relationship between sEEV, sVt, and the expression of Tnfa, where high Vt in combination with high EEV or very low EEV was associated with an increase in gene expression. In endotoxemia there was an association between low sEEV, particularly when this was combined with moderate sVt, and high expression of IL6. Our data suggest that preexisting systemic inflammation modifies the relationship between regional lung volumes and inflammation and that although optimum EEV-Vt combinations to minimize injury exist, further studies are required to identify the critical inflammatory mediators to assess and the effect of different injury types on the response.

scholarly journals Resolvin D1 Alleviates Ventilator-Induced Lung Injury in Mice by Activating PPARγ/NF-κB Signaling Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Haifa Xia ◽  
Jingxu Wang ◽  
Shujun Sun ◽  
Fuquan Wang ◽  
Yiyi Yang ◽  
...  
Keyword(s):  
Lung Injury ◽  
Protective Effect ◽  
Tidal Volume ◽  
Signaling Pathways ◽  
Lung Tissue ◽  
Fatty Acid Derivative ◽  
High Tidal Volume ◽  
Treatment Modalities ◽  
Resolvin D1 ◽  
Ventilator Induced Lung Injury

As one of the basic treatment modalities in the intensive care unit (ICU), mechanical ventilation can cause or aggravate acute lung injury or ventilator-induced lung injury (VILI). Resolvin D1 (RvD1) is an endogenous polyunsaturated fatty acid derivative with strong anti-inflammatory action. In this study, we explored if RvD1 possesses a protective effect on VILI. Mice were ventilated with high tidal volume (40 mL/kg, HVT) for 4 h and were then intraperitoneally administered RvD1 at the beginning of high tidal volume ventilation and given GW9662 (a PPAR-γ antagonist) intraperitoneally 30 min before ventilation. RvD1 attenuated VILI, as evidenced by improved oxygenation and reduced histological injury, compared with HVT -induced lung injury. Similarly, it could ameliorate neutrophil accumulation and production of proinflammatory cytokines in lung tissue. In contrast, the protective effect of RvD1 on lung tissue could be reversed by GW9662. RvD1 mitigated VILI by activating peroxisome proliferator-activated receptor gamma (PPAR-γ) and inhibiting nuclear factor-kappa B (NF-κB) signaling pathways in mice. In conclusion, RvD1 could reduce the inflammatory response in VILI by activating PPAR-γ and inhibiting NF-κB signaling pathways.

scholarly journals Redox Balance and Cellular Inflammation in the Diaphragm, Limb Muscles, and Lungs of Mechanically Ventilated Rats

2010 ◽  
Vol 112 (2) ◽  
pp. 384-394 ◽  
Author(s):  
Judith Marín-Corral ◽  
Leticia Martínez-Caro ◽  
José A. Lorente ◽  
Marta de Paula ◽  
Lara Pijuan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mechanical Ventilation ◽  
Lung Injury ◽  
Protein Adducts ◽  
Organ Injury ◽  
Mechanically Ventilated ◽  
Ventilator Induced Lung Injury ◽  
Cellular Inflammation ◽  
Cell Counts ◽  
Limb Muscles

Background High tidal volume (VT) mechanical ventilation was shown to induce organ injury other than lung injury and systemic inflammation in animal models of ventilator-induced lung injury. The authors aimed to explore whether high VT mechanical ventilation per se induces early oxidative stress and inflammation in the diaphragm, limb muscles, and lungs of healthy rats exposed to ventilator-induced lung injury. Methods Protein carbonylation and nitration, antioxidants (immunoblotting), and inflammation (immunohistochemistry) were evaluated in the diaphragm, gastrocnemius, soleus, tibialis anterior, and lungs of mechanically ventilated healthy rats and in nonventilated control animals (n = 8/group) for 1 h, using two different strategies (moderate VT [VT = 9 ml/kg] and high VT [VT = 35 ml/kg]). Results The main findings are summarized as follows: compared with controls, (1) the diaphragms and gastrocnemius of high-VT rats exhibited a decrease in reactive carbonyls, (2) the soleus and tibialis of high- and moderate-VT rodents showed a reduction in reactive carbonyls and malondialdehyde-protein adducts, (3) the lungs of high-VT rats exhibited a significant rise in malondialdehyde-protein adducts, (4) the soleus and tibialis of both high- and moderate-VT rats showed a reduction in protein nitration, (5) the lungs of high- and moderate-VT rats showed a reduction in antioxidant enzyme levels, but not in the muscles, and (6) the diaphragms and gastrocnemius of all groups exhibited very low inflammatory cell counts, whereas the lungs of high-VT rats exhibited a significant increase in inflammatory infiltrates. Conclusions Although oxidative stress and inflammation increased in the lungs of rats exposed to high VT, the diaphragm and limb muscles exhibited a decline in oxidative stress markers and very low levels of cellular inflammation.

Inhibition of matrix metalloproteinase-9 prevents neutrophilic inflammation in ventilator-induced lung injury

2006 ◽  
Vol 291 (4) ◽  
pp. L580-L587 ◽  
Author(s):  
Je Hyeong Kim ◽  
Min Hyun Suk ◽  
Dae Wui Yoon ◽  
Seung Heon Lee ◽  
Gyu Young Hur ◽  
...  
Keyword(s):  
Lung Injury ◽  
Matrix Metalloproteinase ◽  
Tidal Volume ◽  
Weight Ratio ◽  
Dry Weight ◽  
Neutrophil Infiltration ◽  
Neutrophilic Inflammation ◽  
Ventilator Induced Lung Injury ◽  
Metalloproteinase 9 ◽  
Expression And Activity

Neutrophils are considered to play a central role in ventilator-induced lung injury (VILI). However, the pulmonary consequences of neutrophil accumulation have not been fully elucidated. Matrix metalloproteinase-9 (MMP-9) had been postulated to participate in neutrophil transmigration. The purpose of this study was to investigate the role of MMP-9 in the neutrophilic inflammation of VILI. Male Sprague-Dawley rats were divided into three groups: 1) low tidal volume (LVT), 7 ml/kg of tidal volume (VT); 2) high tidal volume (HVT), 30 ml/kg of VT; and 3) HVT with MMP inhibitor (HVT+MMPI). As a MMPI, CMT-3 was administered daily from 3 days before mechanical ventilation. Degree of VILI was assessed by wet-to-dry weight ratio and acute lung injury (ALI) scores. Neutrophilic inflammation was determined from the neutrophil count in the lung tissue and myeloperoxidase (MPO) activity in the bronchoalveolar lavage fluid (BALF). MMP-9 expression and activity were examined by immunohistochemical staining and gelatinase zymography, respectively. The wet-to-dry weight ratio, ALI score, neutrophil infiltration, and MPO activity were increased significantly in the HVT group. However, in the HVT+MMPI group, pretreatment with MMPI decreased significantly the degree of VILI, as well as neutrophil infiltration and MPO activity. These changes correlated significantly with MMP-9 immunoreactivity and MMP-9 activity. Most outcomes were significantly worse in the HVT+MMPI group compared with the LVT group. In conclusion, VILI mediated by neutrophilic inflammation is closely related to MMP-9 expression and activity. The inhibition of MMP-9 protects against the development of VILI through the downregulation of neutrophil-mediated inflammation.

scholarly journals Desflurane Attenuates Ventilator-Induced Lung Injury in Rats with Acute Respiratory Distress Syndrome

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Xue Lin ◽  
Ying-nan Ju ◽  
Wei Gao ◽  
Dong-mei Li ◽  
Chang-chun Guo
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Lung Injury ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Tidal Volume ◽  
Lung Tissue ◽  
Rat Model ◽  
Distress Syndrome ◽  
Inflammatory Factors ◽  
Ventilator Induced Lung Injury

Ventilator-induced lung injury aggravates the existing lung injury. This study investigated the effect of desflurane on VILI in a rat model of acute respiratory distress syndrome. Forty-eight rats were randomized into a sham (S) group, control (C) group, lipopolysaccharide/ventilation (LV) group, lipopolysaccharide/ventilation/desflurane (LVD) group, or lipopolysaccharide/low ventilation with and without desflurane (LLV and LLVD) groups. Rats in the S group received anesthesia only. Rats in the LV and LVD groups received lipopolysaccharide and were ventilated with a high tidal volume. Rats in LLV and LLVD groups were treated as the LV and LVD groups and ventilated with a low tidal volume. PaO2/FiO2, lung wet-to-dry weight ratios, concentrations of inflammatory factors in serum and BALF, histopathologic analysis of lung tissue, and levels of nuclear factor- (NF-) κB protein in lung tissue were investigated. PaO2/FiO2 was significantly increased by desflurane. Total cell count, macrophages, and neutrophils in BALF and proinflammatory factors in BALF and serum were significantly decreased by desflurane, while IL-10 was increased. The histopathological changes and levels of NF-κB protein in lung tissue were decreased by desflurane. The results indicated that desflurane ameliorated VILI in a rat model of acute respiratory distress syndrome.

A Metabolomic Approach to the Pathogenesis of Ventilator-induced Lung Injury

2014 ◽  
Vol 120 (3) ◽  
pp. 694-702 ◽  
Author(s):  
José L. Izquierdo-García ◽  
Shama Naz ◽  
Nicolás Nin ◽  
Yeny Rojas ◽  
Marcela Erazo ◽  
...  
Keyword(s):  
Lung Injury ◽  
Bronchoalveolar Lavage ◽  
Tidal Volume ◽  
Lung Tissue ◽  
Metabolic Profiling ◽  
Metabolic Profile ◽  
Bronchoalveolar Lavage Fluid ◽  
Lavage Fluid ◽  
Positive End Expiratory Pressure ◽  
Ventilator Induced Lung Injury

Abstract Background: Global metabolic profiling using quantitative nuclear magnetic resonance spectroscopy (MRS) and mass spectrometry (MS) is useful for biomarker discovery. The objective of this study was to discover biomarkers of acute lung injury induced by mechanical ventilation (ventilator-induced lung injury [VILI]), by using MRS and MS. Methods: Male Sprague–Dawley rats were subjected to two ventilatory strategies for 2.5 h: tidal volume 9 ml/kg, positive end-expiratory pressure 5 cm H2O (control, n = 14); and tidal volume 25 ml/kg and positive end-expiratory pressure 0 cm H2O (VILI, n = 10). Lung tissue, bronchoalveolar lavage fluid, and serum spectra were obtained by high-resolution magic angle spinning and 1H-MRS. Serum spectra were acquired by high-performance liquid chromatography coupled to quadupole-time of flight MS. Principal component and partial least squares analyses were performed. Results: Metabolic profiling discriminated characteristics between control and VILI animals. As compared with the controls, animals with VILI showed by MRS higher concentrations of lactate and lower concentration of glucose and glycine in lung tissue, accompanied by increased levels of glucose, lactate, acetate, 3-hydroxybutyrate, and creatine in bronchoalveolar lavage fluid. In serum, increased levels of phosphatidylcholine, oleamide, sphinganine, hexadecenal and lysine, and decreased levels of lyso-phosphatidylcholine and sphingosine were identified by MS. Conclusions: This pilot study suggests that VILI is characterized by a particular metabolic profile that can be identified by MRS and MS. The metabolic profile, though preliminary and pending confirmation in larger data sets, suggests alterations in energy and membrane lipids. SUPPLEMENTAL DIGITAL CONTENT IS AVAILABLE IN THE TEXT

scholarly journals Inhibition of Poly(Adenosine Diphosphate–Ribose) Polymerase Attenuates Ventilator-induced Lung Injury

2008 ◽  
Vol 108 (2) ◽  
pp. 261-268 ◽  
Author(s):  
Rosanna Vaschetto ◽  
Jan W. Kuiper ◽  
Shyh Ren Chiang ◽  
Jack J. Haitsma ◽  
Jonathan W. Juco ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Lung Injury ◽  
Tidal Volume ◽  
Interleukin 6 ◽  
Inflammatory Responses ◽  
Adenosine Diphosphate ◽  
High Tidal Volume ◽  
Positive End Expiratory Pressure ◽  
Ventilator Induced Lung Injury ◽  
Pharmacologic Inhibition

Background Mechanical ventilation can induce organ injury associated with overwhelming inflammatory responses. Excessive activation of poly(adenosine diphosphate-ribose) polymerase enzyme after massive DNA damage may aggravate inflammatory responses. Therefore, the authors hypothesized that the pharmacologic inhibition of poly(adenosine diphosphate-ribose) polymerase by PJ-34 would attenuate ventilator-induced lung injury. Methods Anesthetized rats were subjected to intratracheal instillation of lipopolysaccharide at a dose of 6 mg/kg. The animals were then randomly assigned to receive mechanical ventilation at either low tidal volume (6 ml/kg) with 5 cm H2O positive end-expiratory pressure or high tidal volume (15 ml/kg) with zero positive end-expiratory pressure, in the presence and absence of intravenous administration of PJ-34. Results The high-tidal-volume ventilation resulted in an increase in poly(adenosine diphosphate-ribose) polymerase activity in the lung. The treatment with PJ-34 maintained a greater oxygenation and a lower airway plateau pressure than the vehicle control group. This was associated with a decreased level of interleukin 6, active plasminogen activator inhibitor 1 in the lung, attenuated leukocyte lung transmigration, and reduced pulmonary edema and apoptosis. The administration of PJ-34 also decreased the systemic levels of tumor necrosis factor alpha and interleukin 6, and attenuated the degree of apoptosis in the kidney. Conclusion The pharmacologic inhibition of poly(adenosine diphosphate-ribose) polymerase reduces ventilator-induced lung injury and protects kidney function.

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