Respiratory Training Improves Blood Pressure Regulation in Individuals With Chronic Spinal Cord Injury

Abstract

Objective To investigate the effects of resistive Respiratory Motor Training (RMT) on pulmonary function and orthostatic stress-mediated cardiovascular and autonomic responses in individuals with chronic Spinal Cord Injury (SCI). Design Before-after intervention case-controlled clinical study. Setting Participants Individuals with chronic C3-T2 SCI diagnosed with orthostatic hypotension (OH) (n=11) and healthy, non-injured (NI) controls (n=10). Intervention 21 ± 2 (mean ± SD) sessions of resistive inspiratory-expiratory RMT performed 5 days a week during a one-month period. Main Outcome Measures Standard Pulmonary Function Test (PFT): Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), Maximal Inspiratory Pressure (PImax), and Maximal Expiratory Pressure (PEmax) and beat-to-beat arterial blood pressure (BP), heart rate (HR), and respiratory rate during orthostatic sit-up stress test acquired before and after RMT program. Results Completion of RMT intervention abolished OH in 7 out of 11 individuals. FVC, low-frequency component of power spectral density (LF PSD) of BP and HR oscillations, baroreflex effectiveness and cross correlations between BP, HR, and respiratory rate during orthostatic challenge were significantly improved, approaching levels observed in NI individuals. These findings indicate increased sympathetic activation and baroreflex effectiveness in association with improved respiratory-cardiovascular interactions in response to the sudden decrease in BP. Conclusion Resistive respiratory training increases respiratory capacity and improves orthostatically mediated respiratory, cardiovascular, and autonomic responses suggesting that this intervention can be an efficacious therapy for managing OH after SCI.

Respiratory muscle training in athletes with cervical spinal cord injury: effects on cardiopulmonary function and exercise capacity

“…There was no effect of RMT on lung volumes (except a lower FRC at follow‐up), which is in disagreement with the only two previous studies investigating the effect of combined RMT on lung function, both of which reported improved FVC (Aslan et al . ; Legg Ditterline et al . ).…”

“…Although studies of RMT in individuals with SCI of all levels and completeness have reported improved forced VC (FVC) and blood pressure (BP) regulation (Aslan et al . ; Legg Ditterline et al . ), the effects of RMT on exercise performance and cardiopulmonary function have not been examined.…”

Impact of respiratory muscle training on blood gases and pulmonary function among patients with cervical spinal cord injury

“…(27). Moreover, Aslan et al proved that resistive respiratory muscle training for one month significantly improved blood pressure regulation and pulmonary function (FVC and FEV1) in patients with C3-T2 chronic spinal cord lesion (14). Finally, Berlowitz and Tamplin in their meta-analysis study, which included 11 studies on patients with cervical spinal cord injury, stated that Respiratory muscle training significantly improved vital capacity, maximal inspiratory pressure and maximal expiratory pressure (16).…”

“…The total management of patients requires a holistic, multidisciplinary approach to ensure effective rehabilitation, which depends upon awareness of the risks, and a thorough understanding of the pathophysiology of mucus plugging atelectasis and the alterations in pulmonary mechanics (14). However, the leading causes of morbidity and mortality in spinal cord injury population are airway mucus plugging and atelectasis (15).…”

Response to Letter to the Editor regarding “Effects of respiratory training on heart rate variability and baroreflex sensitivity in individuals with chronic spinal cord injury”

“…The objective of the reported study was to investigate if our original reciprocal respiratory training approach, already reported to be effective in improving blood pressure regulation in individuals with SCI-induced orthostatic hypotension 2 , can affect baroreflex function which is often deconditioned in the general SCI population. Study groups intentionally included participants with different levels and severity of injury with a variety of respiratory-cardiovascular functional states.…”