Interaction between diaphragm thickness and weaning inmechanically ventilated patients

Objective: To study the effects of diaphragm thickness, diaphragm excursion and diaphragmatic thickening fraction on weaning of mechanically ventilated patients. The effects of age, gender, BMI, ΔP, total fluid balance, APACHE II and SOFA scores on the diaphragm thickness were also evaluated. Methods: Patients requiring mechanical ventilation by far the most five hours and age older than 18 years were included in the study after being informed and written consents were obtained. The present prospective designed study was completed between 01.01.2019 - 30.06.2021. Patients with morbid obesity, history of neuromuscular disorders, known anatomical malformation of the diaphragm, use of any muscle paralyzing agent and corticosteroids, history of penetrating injury through diaphragm and known pregnancy were excluded. Demographic data; (age, gender, weight, height, body mass index) and the admitting diagnosis were recorded. The daily USG measurements, type of the mechanical ventilation support (invasive/non-invasive), driving pressure "ΔP" levels, arrival and daily APACHE II/SOFA scores, and fluid balance status of the patients were also recorded while the patients were under mechanical ventilation support, and also on the next day of ventilator liberation. The diaphragm USG parameters (the end-inspiratory and end-expiratory diaphragm thickness, diaphragm-muscle thickening-ratio and diaphragm excursion parameters) were measured by using bedside portable "Siemens Acuson P500" ultrasound device, while patients were in the supine position. Results: One hundred patients of whom sixty-four males and mean age calculated were 57,55 years, were studied. Ninety-two patients were supported by IMV and eight of the remaining were supported by NIVM. The mean MV duration was found 7.24 days. Statistically significant increase was found in the diaphragm thickness, as BMI increases. The diaphragm thickness decreases significantly, as age and APACHE II score increases. Also, the diaphragm thickening fraction (TFdi) and diaphragm excursion decreases significantly, as MV time and APACHE II score increases. TFdi decreases significantly with an increase in total fluid balance. Gender and MV types (IMV/NIMV) did not interact with results of diaphragm USG measurements. Diaphragm thickness, TFdi, and DE values were found significantly lower in patients having high ΔP levels, extended MV days, high SOFA scores and high APACHE II scores at ICU admission. Conclusion: The diaphragm USG is a non-invasive and assistful technique that might make valuable contribution on planning and managing mechanical ventilation. Key words: mechanical ventilation, diaphragm thickness, weaning, ultrasonography.