Effect of 4 weeks resistive inspiratory muscle training on respiratory functions in patients with tetraplegia during in-patient rehabilitation

Abstract

There is reduction in lung compliance in first week after spinal cord injury (SCI) that deteriorates further and neuroprotective therapies like strength training of respiratory muscles should begin in first month after SCI since both motor and sensory scores at baseline and their further recovery is maximum during this phase. Few studies on SCI subjects within first month of injury have supported use of resistive inspiratory muscle training (RIMT), but have advocated the need for further research in this patient population owing to pitfalls in these studies. The present study was a prospective randomized control trial being carried out to determine whether RIMT programme of four weeks duration is effective in improving respiratory functions and strength in motor complete cervical SCI patients (AIS grade A, B) during in-patient rehabilitation. Patients within first week of cervical SCI (C4-C7 level) were assigned to RIMT (48 patients) and Control (48 patients) group and completed 40 supervised training sessions over a period of four weeks. Outcome measures included: - Spirometry, inspiratory and expiratory muscle strength. No significant differences of Chi-square test (P < 0.05) and unpaired “t” test (P < 0.05) were found between RIMT and Control group for all demographic and pre-training measurements. Following results were recorded after 2 weeks and 4 weeks of training on all outcome measures: - Highly significant difference (P<0.01) within both groups with One–way ANOVA; Highly significant difference (P<0.01) with unpaired “t-test” between RIMT and control group. Cohen “d” effect sizes for RIMT vs. Control group were in large effect size zone i.e. greater than 0.8. The findings of present study show beneficial effect of RIMT on respiratory functions and strength in patients with tetraplegia in first month post injury and we propose that RIMT should be included early in acute phase rehabilitation of these patients.