Project description:In the present study we seek to identify changes in lung gene expression under mechanical ventilation in uninjured as well as acutely and chronically injured lungs. A standard volume-controlled lung-protective ventilatory protocol is compared to a concept of mechanical ventilation using variable tidal volumes.
Project description:Addition of CO2 to the inspired gas can ameliorate lung injury during high tidal volume mechanical ventilation in animal models. Although some effects of hypercapnia on physiology and cell signaling have been characterized, we hypothesized that assessment of genome-wide gene expression patterns would reveal novel pathways of protection. We subjected male C57BL/6J mice to non-injurious low stretch (tidal vol = 10 mL/kg, PEEP = 2 cm H2O) or injurious high stretch (tidal volume approx 35 mL/kg, PEEP = 0 cm H2O) mechanical ventilation for 3 hours under normocapnia (FiCO2 = 0) or hypercapnia (FiCO2 = 0.12).
Project description:To assess the differences between male and female mice submitted to mechanical ventilation, RNA extracted from lung homogenates from mice was compared
Project description:Postoperative Pulmonary Complications (PPC) are very common. It severely affects postoperative recovery, particularly in the abdominal surgery. Patients with laparoscopic resection of colorectal cancer generally have a higher age and decreased lung function reserve. At the same time, they prone to developing atelectasis due to the effects of pneumoperitoneum pressure. Therefore, they are a high-risk group of respiratory insufficiency and PPC.
Mechanical ventilation with a low tidal volume is a routine in clinic nowadays. However, this conventional strategy will also result in atelectasis formation. Therefore, it may deteriorate the vulnerable lung function of patients undergoing laparoscopic resection of colorectal cancer. Patients with Acute Lung Injury or Acute Respiratory Distress Syndrome (ALI/ARDS) could benefit from the "open lung approach", including the use of positive end-expiratory pressure (PEEP) and recruitment maneuvers (RMs). Whether a lung protective mechanical ventilation strategy with medium levels of PEEP and repeated RMs, the "open lung approach", protects against respiratory insufficiency and PPC during laparoscopic resection of colorectal cancer is uncertain. The present study aims at comparing the effects of "open lung approach" mechanical ventilation strategy and conventional mechanical ventilation strategy in PPC, extra-pulmonary complications, length of hospital stay, biomarkers of lung injury and changes of respiratory function in patients undergoing general anesthesia for laparoscopic resection of colorectal cancer.
Project description:In 1967, the term "respirator lung" was coined to describe the diffuse alveolar infiltrates and hyaline membranes that were found on postmortem examination of patients who had undergone mechanical ventilation.This mechanical ventilation can aggravate damaged lungs and damage normal lungs. In recent years, Various ventilation strategies have been used to minimize lung injury, including low tide volume, higher PEEPs, recruitment maneuvers and high-frequency oscillatory ventilation. which have been proved to reduce the occurrence of lung injury.
In 2012,Needham et al. proposed a kind of lung protective mechanical ventilation, and their study showed that limited volume and pressure ventilation could significantly improve the 2-year survival rate of patients with acute lung injury.Volume controlled ventilation is the most commonly used method in clinical surgery at present.Volume controlled ventilation(VCV) is a time-cycled, volume targeted ventilation mode, ensures adequate gas exchange. Nevertheless, during VCV, airway pressure is not controlled.Pressure controlled ventilation(PCV) can ensure airway pressure,however minute ventilation is not guaranteed.Pressure controlled ventilation-volume guarantee(PCV-VG) is an innovative mode of ventilation utilizes a decelerating flow and constant pressure. Ventilator parameters are automatically changed with each patient breath to offer the target VT without increasing airway pressures. So PCV-VG has the advantages of both VCV and PCV to preserve the target minute ventilation whilst producing a low incidence of barotrauma pressure-targeted ventilation.
Current studies on PCV-VG mainly focus on thoracic surgery, bariatric surgery and urological surgery, and the research indicators mainly focus on changes in airway pressure and intraoperative oxygenation index.The age of patients undergoing laparoscopic colorectal cancer resection is generally higher, the cardiopulmonary reserve function is decreased, and the influence of intraoperative pneumoperitoneum pressure and low head position increases the incidence of intraoperative and postoperative pulmonary complications.Whether PCV-VG can reduce the incidence of intraoperative lung injury and postoperative pulmonary complications in elderly patients undergoing laparoscopic colorectal cancer resection, and thereby improve postoperative recovery of these patients is still unclear.
Project description:Gene expression profiling was performed in lung tissues from an animal model of sepsis challenged with injurious and non-injurious mechanical ventilation to unravel the molecular pathways involved in acute lung injury. Sepsis was induced in male Sprague Dawley rats by means of cecal ligation and puncture. Septic rats were randomly allocated to three distinct groups: spontaneous breathing, mechanically ventilated with high tidal volume with zero positive end expiratory pressure (PEEP) and with low tidal volume and 10 cmH2O of PEEP. Comparisons were performed against an unventilated control group.
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