Assessment of diaphragmatic mobility by chest ultrasound in relation to BMI and spirometric parameters

Context Ultrasound of the diaphragm is an evolving diagnostic modality with several techniques and measurements that can be used for structural and functional assessment of the diaphragm. Weight may have effects on pulmonary function tests including its impairment. Assessment of the diaphragm is one of these important measures of function by measuring the diaphragmatic thickness, excursion, and diaphragmatic thickness fraction (DTF). Aim Assessing the relation between these sonographic diaphragmatic indices with spirometry and BMI. Settings and design This was a prospective clinical study in which 107 normal healthy volunteers with different age, height, and weight were enrolled; most of them were coming for routine preoperative assessment at the Ain Shams University Chest Department Pulmonary Function Unit. Patients and methods It included 107 healthy persons who came for routine preoperative lung function assessment or normal volunteers. Full medical and smoking history, BMI, chest radiography spirometry, and diaphragmatic assessment by ultrasound for excursion, thickness, and DTF were done. All persons were divided into obese individuals of BMI more than or equal to 25 and nonobese individuals of BMI less than 25. Statistical analysis Statistical package for the social sciences program (SPSS) software version 18.0. Results In obese individuals, forced expiratory volume in the first second (FEV1%) and right diaphragmatic excursion show a significant decrease when BMI increases. There was a statistically significant increase in right and left diaphragmatic excursion and DTF in men rather than women. There was a highly significant increase in both right and left diaphragmatic thickness and excursion when forced vital capacity increases. There was a highly significant increase in right diaphragmatic excursion and both right and left diaphragmatic thickness when FEV1 increases. A significant increase in left excursion and DTF was also noticed with increased FEV1. However, there was a significant decrease in DTF with increased percent of forced vital capacity. Conclusion Spirometric parameters and right diaphragmatic excursion show a significant decrease when BMI increases. Different relations were found between spirometric parameters and ultrasonographic measurements regardless of the BMI.