Can we identify patients that recover strength following hospitalisation for an acute exacerbation of chronic respiratory disease

Introduction: During an acute exacerbation of chronic respiratory disease, peripheral muscle weakness is more pronounced and exercise capacity is reduced when compared with stable patients. Methods: Maximal isometric quadriceps strength (QMVC) was measured at baseline and 6 weeks from participants in an early rehabilitation randomised controlled trial (n= 230) (Greening et al, BMJ 2014:g4315). As no difference between groups had previously been noted (p=0.8) the groups were combined and treated as a single cohort. Recovery was defined as a positive change in strength from baseline to 6 weeks. Results: Significant increase in QMVC was seen (mean change 7%, p 1 43% (±18%), BMI 26.4 (±6.8 kg/m 2 ), baseline QMVC 13.1 (±7.6) Kg, MRC 4 (IQR4-5)]. 90 (39%) patients did not recover [mean (SD) age 70 (±10) years, FEV 1 48% (±20%),BMI 26.9 (±6.8) kg/m 2 ,baseline QMVC 15.0 (±7.2), MRC 4 (IQR 3-4.75)]. Sub-group analysis was not able to identify patients that were more likely to recover (see figure). Discussion: There was significant recovery seen in muscle strength from baseline to 6 weeks. However there were no significant differences between responders and non-responders. No sub-groups that were more likely to recover could be prospectively identified.