Ventilation asymmetry, diaphragmatic mobility and exercise capacity in men with traumatic brachial plexus injury

To investigate the repercussions of traumatic brachial plexus injury (TBPI) on diaphragmatic mobility and exercise capacity, compartmental volume changes, as well as volume contribution of each hemithorax and ventilation asymmetry during different respiratory maneuvers, and compare with healthy individuals. The velocity of shortening of the diaphragm, inspiratory, and expiratory muscles were also assessed.

The cross-sectional study was conducted with 40 male individuals (20 with TBPI who have not undergone nerve transfer surgery [mean age 30.1 ± 5.3] and 20 healthy paired by age and body mass index). Only patients with C8-T1 root avulsion were studied.

Compartmental and hemithoracic volumes, as well as asymmetry between the affected and unaffected sides were assessed using optoelectronic plethysmography. The 6 minute walking test was performed to evaluate exercise capacity, while diaphragm mobility was assessed during quiet breathing (QB) using an ultrasound device.

TBPI patients with mean lesion time of 174 ± 45.24 days showed a decreased pulmonary function, respiratory muscle strength, exercise capacity, and diaphragm mobility (all p < .001) compared with healthy. The pulmonary ribcage compartment of the affected side was the main contributor to the reduction in volume during inspiratory capacity, vital capacity, and inspiratory load imposition (all p < .05). This compartment also exhibited a higher ventilation asymmetry with reduced shortening velocity of the inspiratory ribcage muscles.

Compared with healthy, TBPI patients who have not undergone nerve transfer surgery present low exercise capacity and diaphragmatic mobility, as well as reduced volume of the upper ribcage compartment on the affected side that leads to reduced shortening velocity and ventilation asymmetry.