Time recovery course of maximum inspiratory and expiratory pressures in patients with spinal cord injury (lower cervical tract)

Aim of the Study: In quadriplegic patients with injuries below C5 segment of the cervical cord, the intercostal and abdominal muscles are paralysed so that ventilation is almost totally supported by diaphragm. We undertook this study in order to evaluate the degree of improvement of the respiratory muscles performance in quadriplegics patients admitted to an intensive rehabilitation program after the acute phase of injury. Methods: We have enrolled 10 males and 1 female, mean age 46 years, with a cervical lesion C5-C7. All patients were tracheostomized and spontaneous ventilating via a tracheostomy tube. Both maximum inspiratory and expiratory pressures (Pimax, Pemax) were measured at admission and at the time when the patients seemed to be able to produce cough by themselves effectively with a standard procedure (the best pressure value of three consecutive inspiratory and expiratory efforts). Results: The mean baseline values were Pimax 26 (SD 4.7) cmH2O Pemax 21.4 (SD 5.2) cmH2O increasing to 38.4 (SD 7.6) and 29.3 (SD 4.3) cmH20 respectively in presence of an effective cough. The mean elapsed time between the first and the second respiratory muscles force measurement was 118 days. Conclusions: The major findings of this study are that respiratory muscles function improves in quadriplegic patients and moreover that a long period of time is necessary to elapse in order to ameliorate pulmonary function by increasing muscle force. Such gains in respiratory performance may be related to retraining of the deconditioned muscles, and to a better recruitment of accessory muscles of ventilation.