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 |
FEF25–75% 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* |
sRaw % pred | -15±50 | -133±57* | -67±57 | -128±51* | -102±43* |
DL,CO/VA % pred | 6±1** | 2±3 | -2±3 | 1±3 | 2±3 |
Steady-state rest (room air) | |||||
Sa,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 |
VT 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 |
tI/tTOT | −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; FEF25–75%: 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; sRaw: specific airway resistance; DL,CO: carbon monoxide diffusing capacity of the lung; VA: alveolar volume; Sa,O2: arterial oxygen saturation; V′O2: oxygen consumption; V′CO2: carbon dioxide arterial tension; V′E: minute ventilation; VT: tidal volume; f: breathing frequency; tI: inspiratory time; tTOT: 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.