Sonographic assessment of the diaphragm has grown increasingly prevalent in the critical care unit since monitoring diaphragmatic function is essential in many therapeutic situations (ICU). Sonography was used to measure diaphragmatic thickness and excursion in connection to various methods of mechanical ventilation (MV) and patient outcomes in order to assess diaphragmatic dynamics in critically sick patients in the intensive care unit. This prospective study was conducted on fifty patients inside the MV respiratory critical care unit. Patients with respiratory symptoms compatible with COVID-19 and those with a diagnosis unrelated to SARS-COV-2 were separated into two equal groups. In addition to normal laboratory and radiological investigations, ICU patients had ultrasound examination of the diaphragm thickness fraction and excursion upon admission and throughout weaning. Significant predictors of weaning success and mortality were the thickness of the inspiration at the end of the MV at weaning, the thickness of the inspiration at the end of the NIV at weaning, and the thickness of the expiration at the end of the MV at weaning. Consequently, the thickness at the end of inspiration and the thickness at the end of expiration were identified as major indications of effective weaning off MV. Significant predictors of effective weaning from NIV were the thickness at the end of inspiration, the thickness at the end of expiration, and the excursion during weaning. Excursion, and thickening at end inspiration and thickening at end expiration in NIV at weaning.