Active clinical trials for "Ventilator-Induced Lung Injury"

Background: Ventilator induced lung injury (VILI) remains a problem in neonatology. High frequency oscillatory ventilation (HFOV) provides effective gas exchange with minimal pressure fluctuation around a continuous distending pressure and therefore small tidal volume. Animal studies showed that recruitment and maintenance of functional residual capacity (FRC) during HFOV ("open lung concept") could reduce lung injury. "Open lung HFOV" is achieved by delivering a moderate high mean airway pressure (MAP) using oxygenation as a guide of lung recruitment. Some neonatologists suggest combining HFOV with recurrent sigh-breaths (HFOV-sigh) delivered as modified conventional ventilator-breaths at a rate of 3/min. The clinical observation is that HFOV-sigh leads to more stable oxygenation, quicker weaning and shorter ventilation. This may be related to improved lung recruitment. This has however to our knowledge not been tested in a clinical trial using modern ventilators. Purpose, aims: To compare HFOV-sigh with HFOV-only and determine if there is a difference in oxygenation expressed as a/A-ratio and/or stability of oxygenation expressed as percentage time with oxygen saturation outside the reference range. To provide information on feasibility and treatment effect of HFOV-sigh to assist planning larger studies. We hypothesize that oxygenation is better during HFOV-sigh. Methods: Infants at 24-36 weeks corrected gestational age already on HFOV are eligible. Patients will be randomly assigned to HFOV-sigh (3 breaths/min) followed by HFOV-only or vice versa for 4 alternating 1-hours periods (2-treatment, double crossover design, each patient being its own control). During HFOV-sigh set-pressure will be reduced to keep MAP constant, otherwise HFOV will remain at pretrial settings. Outcome will be calculated from normal clinical parameters including pulx-oximetry and transcutaneous monitoring of oxygen and carbon-dioxide partial pressures.

Mechanical ventilation can be a life-saving intervention for patients with respiratory failure, but the acutely injured lung is vulnerable to further damage if positive pressure ventilation is not employed judiciously. "Lung protective ventilation" encompasses a group of practices intended to minimize ventilator-induced lung injury (VILI) and includes the delivery of low tidal volumes (to minimize dynamic lung strain) and the prevention of injuriously high airway pressures (to minimize lung stress). The prone position, which compresses (or "loads") the chest wall, more evenly distributes volume and pressure, mitigates the damaging effects of stress/strain, and improves clinical outcomes in patients with severe respiratory failure from adult respiratory distress syndrome (ARDS). Chest wall loading would not be expected to produce these beneficial effects in the supine position-quite the opposite; it usually results in net volume loss and higher airway pressures in response to an unchanging tidal volume. A paradoxical response to chest wall loading, leading to decreased airway pressures, however, was recently reported in a group of patients with advanced lung disease secondary to COVID-19. In this cohort, a paradoxical decrease in airway pressures was elicited during a brief period of manual compression of the abdomen. This maneuver, which is non-invasive, free of cost, and gives real-time information, may have important diagnostic (and potentially therapeutic) implications for ventilator management in patients with respiratory failure.

Randomized controlled trial, comparing two groups of 40 patients each scheduled for open major abdominal surgery. The intervention group was ventilated with a protective strategy consisting on a low Tidal volume (Vt) (6ml/kg of predicted body weight (PBW)), positive end expiratory pressure (PEEP) = 10 cm H2O and recruitment manoeuvres (RM) after disconnection from the ventilator, the control group had classic ventilation (Vt = 8 ml/kg of PBW, PEEP = 4 cmH2O and no RM).

The use of positive end-expiratory pressure (PEEP) has been shown to prevent the cycling end-expiratory collapse during mechanical ventilation and to maintain alveolar recruitment, keeping lung portions open, increasing the resting end-expiratory volume. On the other hand PEEP may also overdistend the already open lung, increasing stress and strain. Theoretically high frequency oscillatory ventilation (HFOV) could be considered an ideal strategy in patients with ARDS for the small tidal volumes, but the expected benefits have not been shown yet. PEEP and HFOV should be tailored on individual physiology. Assuming that the esophageal pressure is a good estimation of pleural pressure, transpulmonary pressure can be estimated by the difference between airway pressure and esophageal pressure (PL= Paw - Pes). A PL of 0 cmH2O at end-expiration should keep the airways open (even if distal zones are not certainly recruited) and a PL of 15 cmH2O should produce an overall increase of lung recruitment. The investigators want to determine whether the prevention of atelectrauma by setting PEEP and mPaw to obtain 0 cmH2O of transpulmonary pressure at end expiratory volume is less injurious than lung recruitment limiting tidal overdistension by setting PEEP and mPaw at a threshold of 15 cmH2O of transpulmonary pressure. The comparison between conventional ventilation with tidal volume of 6 ml/Kg and HFOV enables us to understand the role of different tidal volumes on preventing atelectrauma and inducing lung recruitment. The use of non-invasive bedside techniques such as lung ultrasound, electrical impedance tomography, and transthoracic echocardiography are becoming necessary in ICU and may allow us to distinguish between lung recruitment and tidal overdistension at different PEEP/mPaw settings, in order to limit pulmonary and hemodynamic complications during CMV and HFOV.

There is no accepted standard for the frequency of monitoring endotracheal tube cuff pressures (ETCP). the investigators plan on comparing two strategies for monitoring ETCP in mechanically ventilated patients. Nowadays ETCP is evaluated once every 24 hours. Next, the investigator want to conduct training for medical and nursing staff. After the training, ETCP will be measured every 8 hours. The aim of the study is to prove that more frequent pressure control (3 times a day) reduces the occurrence of abnormal ETCP.

The present pilot randomized controlled clinical trial will test the hypothesis that in patients with ARDS, fixing ventilator settings to the conventional protective ventilatory strategy (VT 6 ml/kg ideal body weight and Pplat ≤ 30 cmH2O, PEEP according the PEEP/FiO2 table), control modes of mechanical ventilation will be associated to a concentration of pulmonary and systemic inflammatory mediators lower than the concentration of inflammatory mediators observed during assisted modes of mechanical ventilation.

Mechanical ventilation is frequently used in the operating room and the intensive care settings. Although essential in many cases, mechanical ventilation can be responsible for ventilator-induced lung injury (VILI). The relationship between mechanical ventilation and VILI has been clearly demonstrated in animals and is highly suspected in humans. The putative mechanism responsible for VILI is excessive pulmonary strain or overdistension. Frequently observed in mechanically ventilated patients, the presence of a severe pre-existing pulmonary disease can increase the risk of overdistension. The development of a tool allowing early detection of pulmonary overdistension would represent a great asset in the prevention of VILI by allowing safer adjustments of mechanical ventilation parameters. Ultrasonographic imaging is a non-radiant, non-invasive technique already available in the intensive care setting. Already used for cardiac strain measurements, ultrasonography is a promising avenue to assess pulmonary strain. This pilot study will aim to create a small dataset of local pleural strain values assessed at predetermined pulmonary areas using ultrasound imaging in patients undergoing thoracic surgery requiring one-lung ventilation. This dataset will be used to help plan larger scale studies.

It is controversial as to which ventilation mode is better in one-lung ventilation(OLV), volume controlled ventilation(VCV) or pressure controlled ventilation(PCV). This study was designed to figure out if there was any difference between these two modes on oxygenation and postoperative complications under the condition of protective ventilation(PV).

Some ICU ventilated patients might present with large tidal volume despite very low or inexistant presser support. Patient-Self Inflicted Lung Injury (P-SILI) might appear related with large alveolar stretch an distension. Two clinical presentations are observed: patients with or without respiratory distress signs such as supra-clavicular depression and thoracic-abdominal asynchronies. The aim of this study is to compare the pulmonary physio(-patho)logical parameters of these two types of patients (eupneic or with respiratory distress signs), and presenting important TV in spite of a minimal adjustment of the ventilatory support, except for Acute Respiratory Distress Syndrome (ARDS).

Neuromuscular blockade (NMB) is proposed in patients with moderate to severe acute respiratory distress syndrome (ARDS). The supposed benefit of these muscle relaxants could be partly linked to their effects on respiratory mechanics by reducing ventilator induced lung injuries (VILI), especially the so called atelectrauma. Although its monitoring is recommended in clinical practice, data about the depth of NMB necessary for an effective relaxation of the thoracic and diaphragmatic muscles and, therefore, the reduction of the chest wall elastance, are scarce. The investigators hypothesised that complete versus partial NMB can modify respiratory mechanics and its partitioning.