Dataset Information

Effect of Low Versus High Tidal-Volume Total Liquid Ventilation on Pulmonary Inflammation.

ABSTRACT: Animal experiments suggest that total liquid ventilation (TLV) induces less ventilator-induced lung injury (VILI) than conventional mechanical gas ventilation. However, TLV parameters that optimally minimize VILI in newborns remain unknown. Our objective was to compare lung inflammation between low (L-VT) and high (H-VT) liquid tidal volume and evaluate impacts on the weaning process. Sixteen anesthetized and paralyzed newborn lambs were randomized in an L-VT group (initial tidal volume of 10 mL/kg at 10/min) and an H-VT group (initial tidal volume of 20 mL/kg at 5/min). Five unventilated newborn lambs served as controls. After 4 h of TLV in the supine position, the lambs were weaned in the prone position for another 4 h. The levels of respiratory support needed during the 4 h post-TLV were compared. The anterior and posterior lung regions were assessed by a histological score and real-time quantitative PCR for IL1B, IL6, and TNF plus 12 other exploratory VILI-associated genes. All but one lamb were successfully extubated within 2 h post-TLV (72 ± 26 min vs. 63 ± 25 min, p = 0.5) with similar FiO2 at 4 h post-TLV (27 ± 6% vs. 33 ± 7%, p = 0.3) between the L-VT and H-VT lambs. No significant differences were measured in histological inflammation scores between L-VT and H-VT lambs, although lambs in both groups exhibited slightly higher scores than the control lambs. The L-VT group displayed higher IL1B mRNA expression than the H-VT group in both anterior (2.8 ± 1.5-fold increase vs. 1.3 ± 0.4-fold increase, p = 0.02) and posterior lung regions (3.0 ± 1.0-fold change increase vs. 1.1 ± 0.3-fold increase, p = 0.002), respectively. No significant differences were found in IL6 and TNF expression levels. Gene expression changes overall indicated that L-VT was associated with a qualitatively distinct inflammatory gene expression profiles compared to H-VT, which may indicate different clinical effects. In light of these findings, further mechanistic studies are warranted. In conclusion, we found no advantage of lower tidal volume use, which was in fact associated with a slightly unfavorable pattern of inflammatory gene expression.

SUBMITTER: Sage M

PROVIDER: S-EPMC7315809 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Effect of Low Versus High Tidal-Volume Total Liquid Ventilation on Pulmonary Inflammation.

Sage Michaël M See Wendy W Nault Stéphanie S Morin Christophe C Michalski Christina C Chabot Benoit B Marouan Sofia S Lavoie Pascal M PM Micheau Philippe P Praud Jean-Paul JP Fortin-Pellerin Étienne É

Frontiers in physiology 20200618

Animal experiments suggest that total liquid ventilation (TLV) induces less ventilator-induced lung injury (VILI) than conventional mechanical gas ventilation. However, TLV parameters that optimally minimize VILI in newborns remain unknown. Our objective was to compare lung inflammation between low (L-VT) and high (H-VT) liquid tidal volume and evaluate impacts on the weaning process. Sixteen anesthetized and paralyzed newborn lambs were randomized in an L-VT gro ...[more]

PMID: 32625110

Similar Datasets

Project description:OBJECTIVE:Low tidal volume ventilation lowers mortality in the acute respiratory distress syndrome. Previous studies reported poor low tidal volume ventilation implementation. We sought to determine the rate, quality, and predictors of low tidal volume ventilation use. DESIGN:Retrospective cross-sectional study. SETTING:One academic and three community hospitals in the Chicago region. PATIENTS:A total of 362 adults meeting the Berlin Definition of acute respiratory distress syndrome consecutively admitted between June and December 2013. MEASUREMENTS AND MAIN RESULTS:Seventy patients (19.3%) were treated with low tidal volume ventilation (tidal volume < 6.5?mL/kg predicted body weight) at some time during mechanical ventilation. In total, 22.2% of patients requiring an FIO2 greater than 40% and 37.3% of patients with FIO2 greater than 40% and plateau pressure greater than 30?cm H2O received low tidal volume ventilation. The entire cohort received low tidal volume ventilation 11.4% of the time patients had acute respiratory distress syndrome. Among patients who received low tidal volume ventilation, the mean (SD) percentage of acute respiratory distress syndrome time it was used was 59.1% (38.2%), and 34% waited more than 72 hours prior to low tidal volume ventilation initiation. Women were less likely to receive low tidal volume ventilation, whereas sepsis and FIO2 greater than 40% were associated with increased odds of low tidal volume ventilation use. Four attending physicians (6.2%) initiated low tidal volume ventilation within 1 day of acute respiratory distress syndrome onset for greater than or equal to 50% of their patients, whereas 34 physicians (52.3%) never initiated low tidal volume ventilation within 1 day of acute respiratory distress syndrome onset. In total, 54.4% of patients received a tidal volume less than 8?mL/kg predicted body weight, and the mean tidal volume during the first 72 hours after acute respiratory distress syndrome onset was never less than 8?mL/kg predicted body weight. CONCLUSIONS:More than 12 years after publication of the landmark low tidal volume ventilation study, use remains poor. Interventions that improve adoption of low tidal volume ventilation are needed.

Project description:BackgroundShedding of the endothelial glycocalyx can be observed regularly during sepsis. Moreover, sepsis may be associated with acute respiratory distress syndrome (ARDS), which requires lung protective ventilation with the two cornerstones of application of low tidal volume and positive end-expiratory pressure. This study investigated the effect of a lung protective ventilation on the integrity of the endothelial glycocalyx in comparison to a high tidal volume ventilation mode in a porcine model of sepsis-induced ARDS.MethodsAfter approval by the State and Institutional Animal Care Committee, 20 male pigs were anesthetized and received a continuous infusion of lipopolysaccharide to induce septic shock. The animals were randomly assigned to either low tidal volume ventilation, high tidal volume ventilation, or no-LPS-group groups and observed for 6 h. In addition to the gas exchange parameters and hematologic analyses, the serum hyaluronic acid concentrations were determined from central venous blood and from pre- and postpulmonary and pre- and postcerebral circulation. Post-mortem analysis included histopathological evaluation and determination of the pulmonary and cerebral wet-to-dry ratios.ResultsBoth sepsis groups developed ARDS within 6 h of the experiment and showed significantly increased serum levels of hyaluronic acid in comparison to the no-LPS-group. No significant differences in the hyaluronic acid concentrations were detected before and after pulmonary and cerebral circulation. There was also no significant difference in the serum hyaluronic acid concentrations between the two sepsis groups. Post-mortem analysis showed no significant difference between the two sepsis groups.ConclusionIn a porcine model of septic shock and ARDS, the serum hyaluronic acid levels were significantly elevated in both sepsis groups in comparison to the no-LPS-group. Intergroup comparison between lung protective ventilated and high tidal ventilated animals revealed no significant differences in the serum hyaluronic acid levels.

Project description:ImportanceIn patients who undergo mechanical ventilation during surgery, the ideal tidal volume is unclear.ObjectiveTo determine whether low-tidal-volume ventilation compared with conventional ventilation during major surgery decreases postoperative pulmonary complications.Design, setting, and participantsSingle-center, assessor-blinded, randomized clinical trial of 1236 patients older than 40 years undergoing major noncardiothoracic, nonintracranial surgery under general anesthesia lasting more than 2 hours in a tertiary hospital in Melbourne, Australia, from February 2015 to February 2019. The last date of follow-up was February 17, 2019.InterventionsPatients were randomized to receive a tidal volume of 6 mL/kg predicted body weight (n = 614; low tidal volume group) or a tidal volume of 10 mL/kg predicted body weight (n = 592; conventional tidal volume group). All patients received positive end-expiratory pressure (PEEP) at 5 cm H2O.Main outcomes and measuresThe primary outcome was a composite of postoperative pulmonary complications within the first 7 postoperative days, including pneumonia, bronchospasm, atelectasis, pulmonary congestion, respiratory failure, pleural effusion, pneumothorax, or unplanned requirement for postoperative invasive or noninvasive ventilation. Secondary outcomes were postoperative pulmonary complications including development of pulmonary embolism, acute respiratory distress syndrome, systemic inflammatory response syndrome, sepsis, acute kidney injury, wound infection (superficial and deep), rate of intraoperative need for vasopressor, incidence of unplanned intensive care unit admission, rate of need for rapid response team call, intensive care unit length of stay, hospital length of stay, and in-hospital mortality.ResultsAmong 1236 patients who were randomized, 1206 (98.9%) completed the trial (mean age, 63.5 years; 494 [40.9%] women; 681 [56.4%] undergoing abdominal surgery). The primary outcome occurred in 231 of 608 patients (38%) in the low tidal volume group compared with 232 of 590 patients (39%) in the conventional tidal volume group (difference, -1.3% [95% CI, -6.8% to 4.2%]; risk ratio, 0.97 [95% CI, 0.84-1.11]; P = .64). There were no significant differences in any of the secondary outcomes.Conclusions and relevanceAmong adult patients undergoing major surgery, intraoperative ventilation with low tidal volume compared with conventional tidal volume, with PEEP applied equally between groups, did not significantly reduce pulmonary complications within the first 7 postoperative days.Trial registrationANZCTR Identifier: ACTRN12614000790640.

Project description:Introduction: The ideal ventilation strategy for patients with massive brain damage requires better elucidation. We hypothesized that in the presence of massive brain injury, a ventilation strategy using low (6 mL/kg) tidal volume (VT) ventilation with open lung positive end-expiratory pressure set according to the minimal static elastance of the respiratory system (LVT/OLPEEP), attenuate the impact of massive brain damage on gas-exchange, respiratory mechanics, lung histology and whole genome alterations compared with high (12 mL/kg) VT and low PEEP ventilation (HVT/LPEEP). Methods: Twenty-eight adult male Wistar rats were randomly assigned to one of four groups: 1) no brain damage (NBD) with LVT/OLPEEP; 2) NBD with HVT/LPEEP; 3) brain damage (BD) with LVT/OLPEEP; and 4) BD with HVT/LPEEP. All animals were mechanically ventilated for six hours. Brain damage was induced by an inflated balloon catheter into the epidural space. Hemodynamics was recorded and blood gas analysis was performed hourly. At the end of the experiment, respiratory system mechanics and lung histology were analysed. Whole genome analysis was performed using Affimetrix gene chips and confirmatory real-time PCR. Results: In NBD, both LVT/OLPEEP and HVT/LPEEP did not affect arterial blood gases, as well as whole genome expression changes and real-time PCR. In BD, LVT/OLPEEP, compared to HVT/LPEEP, reduced lung damage according to histology, genome analysis and real-time PCR with decreased interleukin (IL-6), cytokine-induced neutrophil chemoattractant (CINC)-1 and angiopoietin-4 expressions. LVT/OLPEEP compared to HVT/LPEEP improved overall survival. Conclusions: In BD, LVT/OLPEEP minimizes lung morpho-functional changes and inflammation compared to HVT/LPEEP. LVT/OLPEEP might represent a suitable ventilatory strategy in massive brain damage. 24 Wistar rats - lung samples, 4 groups, 1. non-braindamaged/braindead high tidal volume ventilation, 2. non-braindamaged/braindead best PEEP ventilation, 3. Braindamaged/braindead high tidal volume ventilation, 4. Braindamaged/braindead best PEEP ventilation

Dataset Information

Effect of Low Versus High Tidal-Volume Total Liquid Ventilation on Pulmonary Inflammation.

Publications

Effect of Low Versus High Tidal-Volume Total Liquid Ventilation on Pulmonary Inflammation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets