Effects of mechanical insufflation-exsufflation on compartmental chest wall volume in patients with chronic cervical spinal cord injuries
The purpose of this study was to evaluate the effects of mechanical insufflation-exsufflation (MI-E) on volume change of the chest wall and each compartment of the chest wall in patients with cervical spinal cord injury using optoelectronic plethysmography (OEP). Fourteen male patients with chronic cervical spinal cord injuries were included with the following characteristics: age, 56.2 ± 13.6 years; height, 168.4 ± 5.5 cm; body weight, 62.3 ± 12.7 kg; median number of days after injury, 387 days (range, 200-3575 days). The change of chest wall volume was significantly greater during MI-E of ≥ ±30 cmH2O than when taking a deep breath. The volume change in the upper and lower thorax compartment was significantly greater during MI-E of ≥ ±30 cmH2O than when taking a deep breath. However, MI-E made no significant difference to the volume of the upper and lower thorax compartment between pressures of ±30 cmH2O and ±50 cmH2O. The volume change in the abdomen compartment was slightly greater during MI-E than when taking a deep breath, but this was not statistically significant. The findings of this study indicate the possibility of maintenance or improvement of the compliance of the chest wall, especially the rib cage in patients with spinal cord injuries, using MI-E. In turn, these findings could lead to the prevention of pulmonary complications.