Table. 3—

Recovery from acute exacerbations of chronic obstructive disease as indicated by changes in measurements from study entry (day 0) during follow-up visits

Variable	Day 7	Day 14	Day 30	Day 60	Final visit
Subjects n	8	17	15	15	20
Days post study entry	7±1	15±1	30±1	63±3	60±5 (14–92)
Symptoms
CRQ dyspnoea	0.1±0.4	1.5±0.3**	1.4±0.4**	1.8±0.5**	1.6±0.4**
Modified MRC	−0.8±0.3*	−0.8±0.3**	−0.9±0.4**	-1.0±0.4**	−0.8±0.3*
TDI	3.0±0.7**	2.7±0.7**	2.4±1.0*	3.3±0.9*	2.8±0.8**
Dyspnoea at rest Borg	−0.2±0.6	−0.7±0.3	-1.4±0.5*	-1.1±0.5	-1.6±0.4**
Pulmonary function
FEV₁ L	0.00±0.09	0.12±0.06*	0.13±0.06*	0.24±0.06**	0.19±0.05**
FEV₁/FVC %	-2.5±2.4	−0.2±2.1	1.2±1.8	2.0±1.9	1.4±1.8
FEF_25–75% L·s⁻¹	−0.07±0.04	0.01±0.04	0.04±0.03	0.04±0.04	0.03±0.03
PEFR L·s⁻¹	0.09±0.14	0.70±0.22**	0.65±0.25**	0.64±0.18**	0.60±0.14**
FVC L	0.15±0.12	0.30±0.11**	0.23±0.09**	0.40±0.11**	0.35±0.10**
IC L	0.06±0.07	0.26±0.06**	0.27±0.07**	0.30±0.06**	0.30±0.05**
SVC L	0.27±0.10*	0.34±0.11**	0.32±0.07**	0.47±0.12**	0.38±0.10**
TLC L	0.07±0.15	−0.00±0.09	0.12±0.07	0.13±0.07	0.09±0.06
FRC L	0.00±0.12	−0.28±0.09**	−0.16±0.10*	−0.17±0.07*	−0.20±0.06**
RV L	−0.21±0.11	−0.41±0.11**	−0.20±0.11*	−0.34±0.12*	−0.31±0.10*
_sR_aw % pred	-15±50	-133±57*	-67±57	-128±51*	-102±43*
D_L,CO/V_A % pred	6±1**	2±3	-2±3	1±3	2±3
Steady-state rest (room air)
S_a,O₂ %	0.4±0.2	1.6±0.8	1.5±0.5	2.8±0.9*	2.1±0.9**
V′_O₂ L·min⁻¹	−0.00±0.02	0.02±0.02	0.02±0.02	0.02±0.02	0.01±0.02
V′_CO₂ L·min⁻¹	0.00±0.01	0.01±0.02	0.02±0.02	0.02±0.02	0.01±0.02
V′_E L·min⁻¹	-1.8±1.1	−0.7±0.6	−0.1±0.5	−0.3±0.7	−0.3±0.6
V_T L	0.05±0.04	0.01±0.04	0.02±0.05	0.04±0.06	0.03±0.05
f breaths·min⁻¹	-4.0±0.7**	-1.3±1.0	−0.8±1.3	-1.6±1.1	-1.1±1.0
t_I/t_TOT	−0.01±0.02	−0.02±0.02	−0.00±0.01	−0.00±0.02	−0.02±0.02

Data are presented as mean±sem. CRQ: Chronic Respiratory Disease Questionnaire; MRC: Medical Research Council dyspnoea score; TDI: transition dyspnoea index; FEV₁: forced expiratory volume in one second; FVC: forced vital capacity; FEF_25–75%: forced mid-expiratory flow; PEFR: peak expiratory flow rate; IC: inspiratory capacity; SVC: slow vital capacity; TLC: total lung capacity; FRC: functional residual capacity; RV: residual volume; _sR_aw: specific airway resistance; D_L,CO: carbon monoxide diffusing capacity of the lung; V_A: alveolar volume; S_a,O₂: arterial oxygen saturation; V′_O₂: oxygen consumption; V′_CO₂: carbon dioxide arterial tension; V′_E: minute ventilation; V_T: tidal volume; f: breathing frequency; t_I: inspiratory time; t_TOT: total breathing cycle. *: p<0.05 significant improvement from day 0 by paired t-test once a significant f ratio was obtained by ANOVA for repeated measures across all visit days; **p<0.01.