Clinical Research Directory

PRophylaxis Against Early VENTilator-associated Infections in Acute Brain Injury

This research is about whether treatment with a commonly used antibiotic can prevent infections in airway and lungs and improves the chance of surviving, if it is given soon after patients commence mechanical ventilation when they have been admitted to hospital with an acute severe brain injury. An acute severe brain injury can occur as a result of a stroke, a traumatic injury or due to lack of oxygen to the brain that happens as a result of a cardiac arrest. Patients who are unconscious after an acute severe brain injury often need assistance to breath adequately, and this assistance is given by a breathing tube, connected to a mechanical ventilator. This treatment is an emergency medical treatment. The breathing tube is inserted into the patients' airway by either their mouth or neck. For patients who need assistance with their breathing from a mechanical ventilator, infections in the airways and lungs, known as pneumonia, are a common complication. Everyone naturally has bacteria in their mouth, esophagus and stomach. Clinicians think that during the process of inserting the breathing tube, small amounts of these bacteria can be introduced into the airways and lung when people are unconscious following an acute severe brain injury, or during the process of placing the breathing tube into the airways. These bacteria are now in a place they aren't meant to be and can cause an infections in the airways and lungs known as pneumonia. The purpose of this research is to see if giving one dose of a common antibiotic can prevent patients developing pneumonia, which is associated with having a breathing tube inserted and being on a ventilator, improving the chance of recovery following the acute severe brain injury and ultimately improving the chance of surviving. When patients have a known infection, current guidelines are to treat them with antibiotics. Antibiotics work to kill the bacteria causing the infection. When a patient has an infection in their lungs, they often need to stay on the mechanical ventilator for longer. While current practice is to give patients with a proven infection in their airways and lungs (pneumonia) antibiotics, it is unknown if giving an antibiotic to patients to prevent these infections before they show signs of pneumonia may lead to better outcomes.

Association Between EIT and CT During PEEP Titration in Patients With Acute Respiratory Failure

This observational study will analyze data already collected by the investigators as part of their routine clinical practice from patients with acute respiratory failure (ARF) treated with mechanical ventilation. The study itself does not require any specific intervention. Mechanical ventilation can save the lives of patients with ARF. However, if used improperly, it can exacerbate lung disease and worsen outcomes (Slutsky et al.). Despite decades of animal and clinical research, it remains unclear how to establish the positive end-expiratory pressure (PEEP) during mechanical ventilation to reduce the risk of lung damage. Several methods have been suggested, but none have consistently proven superior to the others (Sahetya et al.). As part of their routine clinical practice, the investigators study the responses to different PEEP levels of patients with ARF undergoing mechanical ventilation by integrating information from various techniques, each examining different aspects of lung morphology and physiology. The methods the investigators use include lung computed tomography (CT) and electrical impedance tomography (EIT). Lung CT is the reference technique for measuring the morphological response to PEEP (Gattinoni et al.). It quantifies the volume of the hyperinflated and non-aerated lung, both of which are related to the risk of mechanical ventilation causing damage (Slutsky et al.). Lung EIT monitors the functional response to PEEP in terms of changes in regional compliance across different PEEP levels. Allegedly, an increase in compliance when PEEP is decreased reveals overdistention, the functional correlate of (worrisome) hyperinflation, at the higher PEEP. A decrease in compliance when PEEP is decreased signals new collapse, the functional correlate of (worrisome) loss of aeration (Franchineau et al.). In the Unit where the investigators work, patients with ARF treated with mechanical ventilation are routinely studied as follows. First, a lung CT with a PEEP of 20 cmH2O and then of 5 cmH2O is obtained. Thereafter, a decremental PEEP test is performed with the EIT, where PEEP is decreased from 20 cmH2O down to 5 cmH2O in steps of 2 or 3 cmH2O. Finally, results are analyzed and compared offline. At the lung CT, decreasing PEEP from 20 to 5 cmH2O is always associated with some decrease in the volume of the hyperinflated lung and some increase in the volume of the non-aerated lung. However, the magnitude of these two effects varies among individuals, and the net response may be defined as the difference between those two competing effects. If the decrease in the volume of the hyperinflated lung is greater than the increase in the volume of the non-aerated lung, the overall response (i.e., less hyperinflation) can be considered positive. PEEP should then be set closer to 5 than to 20 cmH2O. Diversely, if the decrease in the volume of the hyperinflated lung is smaller than the increase in the volume of the non-aerated lung, the overall response (i.e., more loss of aeration) can be considered negative. PEEP should then be set closer to 20 cmH2O (Protti et al.). Similarly, at the lung EIT, decreasing PEEP from 20 to 5 cmH2O is always associated with compliance improvement in some regions (i.e., less overdistension) and worsening in others (i.e., more collapse). Again, the magnitude of these two opposite effects varies among individuals. According to most experts on lung EIT, PEEP should be set at the level where both overdistension and collapse are minimized (the so-called "best" PEEP) (Jonkman et al.). Lung CT requires transfer to the radiology unit, exposure of the patient to radiation, and complex analysis offline. By contrast, lung EIT is virtually risk-free, and analysis can be performed using an automatic algorithm. Nevertheless, lung EIT is less well validated than lung CT. For instance, the assumption that a decrease in compliance in response to a decrease in PEEP is due to new collapse has been questioned (Protti et al., Chiumello et al., Menga et al.). So far, lung CT remains the reference technique for studying individual responses to PEEP, while lung EIT requires further validation. This study aims to verify whether the "best" PEEP identified using lung EIT is strongly associated with the net response assessed using lung CT, when PEEP is decreased from 20 to 5 cmH2O in patients with ARF treated with mechanical ventilation. If so, this would strengthen the rationale for using the lung EIT (which is safer and simpler than the lung CT) to set PEEP.

Pleural Strain by Speckle-Tracking Ultrasound: Feasibility and Driving Pressure Associations

What is this study about? This research aims to test a new ultrasound technology called "speckle tracking" to measure how much the lining of your lungs (pleura) stretches during breathing, especially if you're on a breathing machine (ventilator). Doctors want to see if this technology can help them adjust ventilator settings more safely, reducing the risk of lung damage. Why is this important? Lung protection: Patients on ventilators, especially those with severe lung problems (like ARDS or pneumonia), need careful settings. Too much pressure from the ventilator can harm the lungs. Better monitoring: Current tools can't easily measure lung stretching at the bedside. This ultrasound method might offer a simple, painless way to check lung health in real time. Who can join? Included: Adults (18+ years) in the ICU with serious illness (assessed by a standard score called APACHE II \>8), whether on a ventilator or not. Excluded: People with recent chest surgery, broken ribs, nerve/muscle diseases, or pregnancy (to avoid risks and ensure accurate measurements). What will happen during the study? Ultrasound scans: A small probe will be placed gently on your chest for 5-10 minutes. The machine will record videos of your lung movements during breathing. This is painless and uses no radiation. Measurements: Doctors will repeat the scan twice (10 minutes apart) to check consistency. For ventilator patients, scans will be done at different pressure settings to see how lung stretching changes. How will this help me or others? Direct benefit: You'll receive detailed monitoring of your lung function, which may help doctors personalize your care. Future benefit: If successful, this technology could help doctors worldwide adjust ventilators more safely, reducing complications for ICU patients. Is my information safe? All data (scans, medical records) will be anonymized and stored securely. Participation is voluntary, and you can withdraw anytime without affecting your treatment. Who is conducting the study? Led by Dr. Xu Qiancheng and the ICU team at Yijishan Hospital, Wannan Medical College. Experts in ultrasound and critical care will ensure the study is safe and scientifically rigorous.