equivalence test of two different inspiratory muscle training protocols: a randomised controlled trial

Conditions: Inspiratory Muscle Training

Summary: the objective of this study is to investigate if six weeks of high intensity inspiratory muscle training (imt) performed two times a week has the same effect as five times a week in hospitalized patients with first time spinal cord injury (sci). design/ methods: a randomised controlled trial (rct) including 60 patients, with reduced maximal inspiration pressure (mip) will be recruited at two specialized sci centers in denmark. primary outcome is mip after six weeks of training. secondary outcome will be reported on rating perceived exertion (rpe), voice performance, quality of life (qol)and sleep quality. furthermore, long term follow-up at 12 months after start of intervention will also be performed.

background: sci may result in various disabilities including both physical, cognitive, emotional and social domains. motor function and function of the respiratory muscles are often decreased and may influence the patient's activities of daily activities and qol. imt is training to improve the strength and endurance of diaphragm and the external intercostal muscles. various training protocols of imt have shown efficient to increase lung function. although, a recent meta-analysis suggest that high intensity training may be more efficient it is less clear at what weekly frequency imt should be performed. thus, the objective of this study is to investigate if six weeks of high intensity imt performed two times a week has the same effect as five times a week in hospitalized patients with first time sci. design/ methods: a randomised controlled trial (rct) including 60 patients, with reduced mip will be recruited at two specialized sci centers in denmark. primary outcome is mip after six weeks of training. secondary outcome will be reported on end of treatment and long term follow-up (12 months after start of intervention) in rpe, voice performance, qol and sleep quality. the two intervention arms will consist of one arm training two times a week and the other arm training five times a week. the training protocol in both arms will include five rounds of imt with 12 repetitions at 60 % of mip. mip will be increased 10 % every week if tolerated by the patient until 80 % of mip is reached. after six weeks patients are motivated to continue training by themself up to 12 months after start of intervention.

Eligibility criteria:
inclusion criteria: * first time sci within 0-6 months * age ≥ 18 years * neurological level: c4 -th12 and c1-c4 (ais d only) * severity/ ais: a, b, c or d * able to give informed concent and understand and read danish * mental able to understand and participate in a lung function assessment * decreased mip according to normal gender and age adjusted mip values exclusion criteria: * lung disease or lung infection at the time of inclusion * co-morbidity or other contra indications * injury that hinder mouth shutting * respirator or tracheal tube use * experience of severe dizziness or vomiting during training * not expected to be hospitalised for at least 6 weeks

Keywords: imt maximal inspiratory pressure mip