Diaphragm thickening assessed by ultrasonography is lower than healthy adults in patients with chronic obstructive pulmonary disease
Kazuki Okura, Masahiro Iwakura, Kazuyuki Shibata, Atsuyoshi Kawagoshi, Keiyu Sugawara, Hitomi Takahashi, Masahiro Satake, Takanobu Shioya
Abstract
Abstract Background Ultrasound imaging has been widely used for imaging of the diaphragm thickness (Tdi) and thickening. Few studies assessed the Tdi using ultrasonography in patients with chronic obstructive pulmonary disease (COPD). We measured the Tdi and thickening in patients with COPD compared with healthy younger and healthy older adults to reveal the influence of ageing and/or COPD. Methods Thirty‐eight male patients with COPD (age 72 ± 8 years), 15 healthy younger (age 22 ± 1 years) and 15 healthy older (age 72 ± 5 years) male volunteers were recruited. We measured Tdi at total lung capacity (Tdi TLC ), functional residual capacity (Tdi FRC ) and residual volume (Tdi RV ) using B‐mode ultrasonography. We calculated the change ratio of Tdi TLC and Tdi RV (ΔTdi%). We used a one‐way analysis of variance and multiple comparison test for the comparison analysis. Results The Tdi TLC and the ΔTdi% were significantly lower in patients with COPD compared to the healthy adults. There was no significant difference in these values with age. There was no between group difference in the Tdi FRC or Tdi RV . Conclusions Our results indicate significant differences in Tdi TLC and ΔTdi% between patients with COPD and healthy adults. Therefore, diaphragm ultrasonography can assess diaphragm dysfunction associated with COPD. We suggest that it is better to use Tdi TLC and ΔTdi% (not only Tdi at rest) to assess diaphragm function.