Diaphragmatic excursion measurement in emergency patients with acute dyspnea: toward a new diagnostic tool?

During acute dyspnea (AD), respiratory exhaustion is mainly due to diaphragm fatigue. The primary objective was to validate interobserver reproducibility of diaphragmatic excursion (DE) in emergency department (ED) patients admitted for AD. The secondary objectives were to assess the feasibility of DE measurement and intraobserver reproducibility. Finally, we examined whether the DE value was associated with a need for noninvasive ventilation (NIV).

This was a monocentric, prospective, technical reproducibility study. Adult patients in spontaneous ventilation admitted for AD were included. Two operators carried out 2 consecutive diaphragm excursion measurements each on the right and left hemidiaphragms.

Twenty-four patients were analyzed. The feasibility was 96% on the right and 67% on the left. The interobserver concordance between the 2 measures was 0.80 (95% confidence interval [CI], 0.59-0.91) (average difference, -0.07±0.48 cm) on the right and 0.59 (95% CI, 0.19-0.82) (average difference, 0.30±0.91 cm) on the left. For right DE values inferior to 2.3 cm, the interobserver concordance between measures was 0.92 (95% CI, 0.78-0.97). The intraobserver concordance was 0.89 (95% CI, 0.81-0.94) (average difference, 0.02±0.35 cm) on the right and 0.90 (95% CI, 0.82-0.95) (average difference,-0.06±0.45 cm) on the left. When the DE was greater than 2 cm, no patient required NIV.

Diaphragmatic excursion measurement of the right diaphragm is feasible, with good interobserver and intraobserver reproducibility in ED patients admitted for AD. When the DE value is greater than 2 cm at admission, no subsequent NIV is required.