Comparison of airway occlusion pressure with ultrasound based respiratory indices to predict weaning in critically ill patients A prospective observational study

The purpose of this study is to assess the usefulness of various ultrasound based respiratory indices with respiratory drive parameter in better predicting weaning of critically ill patients from mechanical ventilation. Patients are generally intubated and placed on mechanical ventilator when their own ventilatory and/or gas exchange capabilities are outstripped by the demands placed on them from a variety of diseases. As the conditions that warranted placing the patient on the ventilator stabilize and begin to resolve, attention is directed towards discontinuing the mechanical ventilation as quickly as possible. This process is termed “ventilator weaning”. The process allows patients to resume spontaneous breathing after a gradual reduction in ventilatory support and ultimately helps liberate them from mechanical ventilation. Current guidelines suggest several bedside indices to predict successful weaning and extubation. However, none of these indexes have been proven to be optimal in predicting weaning success. Careful clinical assessments are required to determine the patient’s readiness for weaning and subsequent discontinuation of ventilatory support and, ultimately, successful extubation. To facilitate this process in the study, our primary objective will be comparison of area under the receiver operating characteristic curves(AUROCs) of bedside based ultrasound weaning indices measuring parasternal intercostal muscle thickening fraction/diaphragm thickening fraction ratio(PMTF/DTF) and diaphragm thickening fraction/rapid shallow breathing index ratio (DTF/RSBI) and respiratory drive parameter including airway occlusion pressure (P0.1) in critically ill mechanically ventilated patients to predict weaning  outcomes and minimize extubation failure. The secondary objectives would be to compare P0.1, PMTF/DTF ratio and DTF/RSBI ratios on subsequent spontaneous breathing trials, and to correlate PMTF and DTF on the day of discharge from the ICU with the number of days of mechanical ventilation and length of stay . The ultrasound based respiratory indices have a good ability to predict weaning and extubation outcomes. So, by using these indices & parameters together they can serve as a valuable tool for precise clinical prediction of weaning outcomes