TABLE 1.

Baseline characteristics of ABG substudy cohort dichotomized by deflator/non-deflator

Characteristic	Deflators N=62	Non-Deflators N=67	p-value
Surgical patients – no. (%)	47 (76%)	15 (22%)	<0.0001
Age – yrs	68 (64–71)	67 (63–72)	0.75
Female sex – no. (%)	19 (31%)	14 (21%)	0.23
White race – no. (%)	57 (92%)	58 (87%)	0.40
BMI – kg/m2	24.9 (22.5–27.9)	25.6 (22.5–28.1)	0.79
Pack years	62 (46–86)	60 (40–77)	0.22
Upper lobe predominant distribution of emphysema on CT – no. (%)*	43 (69%)	32 (48%)	0.02
FEV1 % predicted†	28 (22–31)	28 (22–31)	0.82
TLC % predicted†	131 (116–135)	126 (115–137)	0.36
RV % predicted†	215 (184–250)	215 (179–249)	0.34
DLCO % predicted‡	29 (22–36)	29 (24–35)	0.97
RV/TLC	0.63 (0.59–0.68)	0.60 (0.55–0.66)	0.07
Room Air PaO2 – mmHg§	64 (55–72)	63 (55–70)	0.44
Room Air PaCO2 – mmHg§	41 (38–44)	41 (37–45)	0.90
6 min walk distance – m	398 (330–457)	396 (342–444)	0.72
Maximal workload – W	39 (29–60)	39 (25–50)	0.52
O2 pulse – mL/beat	6.8 (5.92–8.72)	7.43 (5.9–9.07)	0.55
Medications
Beta blocker – no. (%)	1 (2%)	0 (0%)	0.48
Digoxin – no. (%)	6 (10%)	2 (3%)	0.15
Anti-hypertensive – no. (%)	11 (18%)	14 (21%)	0.66
Anti-arrhythmic – no. (%)	4 (6%)	4 (6%)	1.00
Long acting beta agonist – no. (%)	35 (56%)	35 (52%)	0.72
Short acting beta agonist – no. (%)	51 (82%)	62 (93%)	0.11
Anticholinergic – no. (%)	53 (85%)	62 (93%)	0.26
Oral bronchodilator – no. (%)	1 (2%)	1 (1%)	1.00
Inhaled corticosteroid – no. (%)	50 (81%)	44 (66%)	0.07

Definition of abbreviations: BMI = body mass index; FEV₁ = forced expiratory volume in one second, TLC = total lung capacity, RV = residual volume, DLCO = diffusing capacity of carbon monoxide Data presented as medians and interquartile ranges unless otherwise specified

^*Non-deflators missing data for one patient

^†Measurement obtained post-bronchodilator

^‡Baseline DLCO was obtained prior to pulmonary rehabilitation; all other baseline pulmonary function measures were completed after pulmonary rehabilitation

^§Deflators missing data for one patient