Ultrasound evaluation of respiratory function of abdominal muscles in normal subjects and chronic obstructive lung disease patients

ABSTRACT

Ultrasonography has been widely used to evaluate diaphragmatic motion and thickness. Little work has been done to evaluate abdominal muscles thickness and function either in normal or disease state using ultrasonography. This work is conducted to evaluate abdominal muscles function in normal and chronic obstructive lung disease patients using ultrasound. We investigated ten COPD patients and ten healthy male control subjects using 7.5 MHz Bmode ultrasound. Thickness of external oblique [EO], Internal oblique [I0], transversus abdominis [TA] and rectus abdominis [RA] was assessed at functional residual capacity [FRC], at residual volume [RV], at total lung capacity [TLC], during maximal expiratory effort [MEE] and progressive expiratory effort [PEE]. In both healthy subjects and COPD, at RV the thickness of I0. TA, RA were increased in thickness compared to FRC. During MEE, the thickness was increased in I0, TA, RA, while there was no change in E0. During PEE, thickness of TA and RA were increased in COPD and control subjects. In all our data the changes in TA were evident with a lesser extent RA and I0. We conclude that transversus abdominis seems to be the major contributor of abdominal muscle function and the use of ultrasound is a useful tool in investigating abdominal muscles