Assessment of expiratory muscle dysfunction in critically ill patients using abdominal ultrasound and association with basal lung atelectasis, diaphragmatic excursion and weaning success – a cross-sectional study.

Expiratory muscles are an important component of respiratory function and muscle pump, especially in critically ill patients. But, it is often neglected by the clinician, who focuses mostly on the inspiratory muscles like diaphragm. The expiratory muscle which are crucial for successful weaning from ventilatory support are rectus abdominis, internal oblique, external oblique and transverse abdominis muscles. The thickness of these muscles should follow a particular order for us to ensure that expiratory muscles are functioning properly. The order of thickness is rectus abdominis>internal oblique>external oblique>transverse abdominis. We aim to analyze this muscle thickness pattern using bedside ultrasound in ICU patients whenever they are being weaned from either non-invasive ventilation or invasive ventilation. So, we will be performing the bedside ultrasound on those weaning days, and we will record the expiratory muscle thickness order , lung ultrasound findings and even the inspiratory muscle (diaphragmatic) excursion. We will correlate these findings to assess whether this has a positive predictive value in spontaneous breathing success. If a correlation is found, the expiratory muscle ultrasound can form a part of future weaning protocols and criteria.

We are prospectively going to recruit 80 patients with the given inclusion and exclusion criteria for the study over a period of one year