Time-courses of lung function and respiratory muscle pressure generating capacity after spinal cord injury: a prospective cohort study.

OBJECTIVE To investigate the time-courses of lung function and respiratory muscle pressure generating capacity after spinal cord injury. DESIGN Multi-centre, prospective cohort study. SUBJECTS One hundred and nine subjects with recent, motor complete spinal cord injury. METHODS Lung function and respiratory muscle pressure generating capacity were measured at first mobilization, at discharge from inpatient rehabilitation and one year after discharge. Lung function was measured in all 109 subjects, and 55 of these performed additional measurements of respiratory muscle pressure generating capacity. Trajectories of respiratory muscle function for different lesion level groups were assessed by multi-variate multi-level regression models. RESULTS Forced vital capacity, forced expiratory volume in 1 sec and maximal inspiratory muscle pressure generating capacity significantly increased during and after inpatient rehabilitation. Forced inspiratory volume in 1 sec, peak inspiratory flow, peak expiratory flow and maximal expiratory muscle pressure generating capacity increased only during inpatient rehabilitation, but not thereafter. Increasing lesion level had a negative effect on all measured lung function parameters, as well as on maximal inspiratory and expiratory muscle pressure generating capacity. CONCLUSION Respiratory function improved during inpatient rehabilitation, but only forced vital capacity, forced expiratory volume in 1 sec and maximal inspiratory muscle pressure generating capacity further improved thereafter. In particular, expiratory muscle function and subjects with tetraplegia should be screened and trained regularly.