Table 5

Association between Borg breathlessness scores and measured variables during exercise in 15 patients with cystic fibrosis before the onset of neuromechanical dissociation (rest to 60% of total exercise time)

Parameter	Spearman (r)	95% CI	p Value
EMGdi%max	0.906	0.483 to 0.986	<0.001
sEMGpara%max	0.906	0.483 to 0.986	<0.001
MV (l/min)	0.906	0.483 to 0.986	<0.001
V′o₂/kg (ml.min.kg)	0.906	0.483 to 0.986	<0.001
PTPdi (cm H₂O.s.l/min)	0.906	0.483 to 0.986	<0.001
PTPoes (cm H₂O.s.l/min)	0.906	0.483 to 0.986	<0.001
TTI	0.906	0.483 to 0.986	<0.001
V′co₂ (l/min)	0.906	0.483 to 0.986	<0.001
Petco₂ (mm Hg)	0.906	0.483 to 0.986	<0.001
RER	0.709	−0.094 to 0.953	0.074
IC (l)	−0.869	−0.980 to −0.328	0.012

EMG, electromyogram; EMGdi%max, diaphragm EMG activity normalised to maximal evoked EMG during inspiratory manoeuvres; IC, inspiratory capacity; MV, minute ventilation; Petco₂, end tidal carbon dioxide; PTPoes, oesophageal pressure time product; PTPdi, diaphragm pressure time product; RER, respiratory exchange ratio; sEMGpara%max, surface parasternal EMG activity normalised to maximal evoked EMG during inspiratory manoeuvres; TTI, tension time index; V′co₂, carbon dioxide production; V′o-₂, oxygen uptake.