Ultrasonographic evaluation of diaphragm function in patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis.

Background: Some studies have reported using ultrasonic evaluations to assess diaphragm function in patients with chronic obstructive pulmonary disease (COPD). However, they have limitations and thus cannot provide strong evidence to support ultrasound evaluations for diaphragm function and dysfunction severity assessments in this patient population. Additionally, quantitative studies on the relationship between ultrasound evaluations and diaphragm function do not exist.