The Relationship Between Diaphragm Function Assessed by Ultrasound and Weaning Success in Mechanically Ventilated Patients in the ICU

The diaphragm is the most important muscle involved in the respiratory system and is solely responsible for approximately 65-80% of vital capacity. When it contracts, it increases the volume of the thoracic cavity, leading to a decrease in intrathoracic pressure and allowing airflow from the atmosphere into the alveoli. Diaphragmatic atrophy begins as early as the first hours of mechanical ventilation (MV). Animal studies have demonstrated that prolonged mechanical ventilation results in diaphragmatic dysfunction, a condition defined as ventilator-induced diaphragmatic dysfunction (VIDD). Ultrasonographic evaluation of the diaphragm has shown a 32% reduction in diaphragmatic strength within the first 72 hours. Assessment of diaphragmatic function is crucial for predicting weaning success. Ultrasonography (USG) is a practical, safe, non-invasive, bedside method that provides real-time results and allows both morphological and functional evaluation of the diaphragm. The ability to assess diaphragmatic contraction simultaneously enables measurement and follow-up of diaphragmatic thickness. This is also clinically useful for diagnosing diaphragmatic dysfunction and diaphragmatic paralysis. The aim of this study was to evaluate the relationship between diaphragmatic function assessed by ultrasonography and weaning success in intubated patients followed in the intensive care unit. In patients admitted to the Intensive Care Unit who received invasive mechanical ventilation for at least 24 hours, were included in the study, were considered ready for the weaning process by the attending clinician independently of the study protocol, and had adequate cognitive function, the following parameters were measured by the investigator prior to separation from mechanical ventilation while the patient was in spontaneous breathing mode (pressure support ventilation, PSV): respiratory rate, minute ventilation, tidal volume, maximal inspiratory pressure (MIP), rapid shallow breathing