The reproducibility of anterior, middle and posterior diaphragm motion assessments with ultrasound / 中华物理医学与康复杂志

ABSTRACT

Objective:To explore the reproducibility of ultrasound measurements of children′s anterior, middle and posterior diaphragm motions.Methods:Thirty children admitted to a pediatric intensive care unit were positioned supine and a 5MHz ultrasound probe was placed over the intersection of their right midclavicular line with the costal margin. M-mode ultrasound was used to record the excursion and contraction velocity of the anterior, middle and posterior diaphragm during respiration. The observations were duplicated so the repeatability of the measurements could be evaluated using intra-group correlation coefficients calculated for the diaphragm excursions and the contraction velocities. Analysis of variance was used to explore the differences in excursion and contraction velocity among different parts of the diaphragm.Results:The intra-group correlation coefficients calculated for the anterior, middle and posterior diaphragm were 0.89, 0.95 and 0.90 respectively. The corresponding values for the contraction velocities were 0.90, 0.94 and 0.95 respectively. Both variables measured by ultrasound showed high repeatability. The average anterior, middle and posterior diaphragm excursion values (in mm) were 8.1±3.1, 7.4±3.0 and 5.5±2.3, and the corresponding average contraction velocities (in mm/s) were 12.5±4.8, 11.5±6.3 and 8.9±4.0.Conclusions:Measurements of children′s diaphragm motions using ultrasound show high repeatability. The excursions and contraction velocities of the anterior, middle and posterior diaphragm differ in children. The motion of one part of the diaphragm cannot represent the functioning of the entire diaphragm.