TABLE 2

Inspiratory neck muscle electromyographic data

Overall populationPIP+PIPp-value (PIP+ versus PIP)
Subjects n1486
EMGmax mV
 Spontaneous breathing12.3 (6.1–18.9)13.8 (8.6–28.1)5.7 (3.1–11.9)0.06
 NIV1.2 (0.6–5.6)1.6 (0.7–5.8)0.6 (0.4–3.4)0.11
 p-value (spontaneous breathing versus NIV)<0.0010.020.06
EMGAUC × fR mV2·min−1
 Spontaneous breathing ×1053.17 (1.0–4.4)3.41 (2.2–7.1)1.03 (0.6–2.8)<0.001
 NIV ×1042.1 (6.1–7.0)2.5 (1.3–8.9)6.4 (5.9–2.4)0.20
 p-value (spontaneous breathing versus NIV)<0.0010.020.06
  • Data are presented as n or median (interquartile range), unless otherwise stated. PIP: pre-inspiratory potentials; EMGmax: peak value of the averaged inspiratory neck muscle electromyographic activity; NIV: noninvasive ventilation; EMGAUC: area under the curve of the averaged inspiratory neck muscle electromyographic activity; fR: respiratory frequency.