Clinical Research Directory

Correlation of Diaphragm Shear-Wave Elastography With Transdiaphragmatic Pressure in Healthy Adults: a Feasibility Study

Changes in intrapleural pressure after lung volume reduction in Chronic Obstructive Pulmonary disease (COPD) patients can lead to complications, including an increased risk of pneumothorax. This procedure, intended to improve lung function, may disturb the pressure balance within the pleural space, potentially precipitating pneumothorax. Careful monitoring of intrapleural pressure could help predict patients at risk. However, intrapleural pressure can currently only be measured invasively. Diaphragm shear-wave elastography (SWE) has been shown to reflect transdiaphragmatic pressure during isovolumetric inspiratory efforts and ventilation against inspiratory loading, and therefore may serve as a non-invasive surrogate for intrapleural pressure. This project outlines a stepwise study plan to evaluate SWE as a tool for intrapleural pressure monitoring (Figure 1). The project only moves to the next phase is the study previous phase was achieved successfully. The current protocol involves the first phase: to validate diaphragm SWE against transdiaphragmatic pressure and assess measurement reliability for local ultrasound systems in healthy adults.This prospective, single-centre, observational validation study will include twelve healthy adult volunteers. During a single study session, participants will perform standardized inspiratory efforts while simultaneous measurements of diaphragm SWE, transdiaphragmatic pressure (via esophageal and gastric balloon catheters), and mouth pressures are obtained. These methods are routinely applied in physiological research and carry minimal risk. Apart from brief nasal or throat discomfort during catheter placement, no significant adverse effects are expected. By establishing the relationship between diaphragm SWE, transdiaphragmatic pressure, and mouth pressures, this study aims to provide the essential validation step for future clinical research in COPD patients following lung volume reduction.

Effects of Neostigmine-dose on Diaphragmatic Dynamics

The goal of this Randomized Clinical Trial is to compare the postoperative diaphragmatic excursion between patients receiving half-dose neostigmine (0.04 mg/kg) and those receiving full-dose neostigmine (0.08 mg/kg) for neuromuscular blockade reversal. The main questions it aims to answer are: * Does half-dose neostigmine result in similar postoperative diaphragmatic excursion compared to full-dose neostigmine? * Does half-dose neostigmine result in similar diaphragmatic thickening fraction compared to full-dose neostigmine? Researchers will compare patients receiving half-dose neostigmine to those receiving full-dose neostigmine to see if there are differences in postoperative diaphragmatic function, respiratory complications, and recovery. Participants will: * Undergo elective laparoscopic cholecystectomy. * Receive either half-dose or full-dose neostigmine for neuromuscular blockade reversal.