Intradialytic Inspiratory Muscle Training at Different Intensities and Functional Capacity

Effects of Intradialytic Inspiratory Muscle Training at Different Intensities on Diaphragm Hypertrophy and Functional Capacity in Patients Undergoing Hemodialysis: a Randomized Clinical Trial.

Investigate the effects of Inspiratory Muscle Training (IMT) performed during hemodialysis (HD) procedures in patients with end stage kidney disease (ESKD). With intervention of thirty-six IMT sessions, performed three times a week, at an intensity of 50%, 30% and 10% (sham) of the maximum inspiratory pressure (MIP).

Introduction: Chronic kidney disease (CKD), especially in its final stage (ESKD), is associated with an increased risk of cardiovascular complications and mortality. Part of this risk can be attributed to the fact that patients with ESKD adopt sedentary behavior. Objectives: To investigate the effects of Inspiratory Muscle Training (IMT) performed during hemodialysis (HD) procedures in patients with ESKD. Methodology: Randomized double-blind clinical trial, controlled by sham. Location: Nephrology Sector, Hospital de Clínicas de Porto Alegre (HCPA) Participants: three groups of 12 patients with ESKD on HD randomized to three IMT intensities. Intervention: Thirty-six IMT sessions, performed three times a week, at an intensity of 50%, 30% and 10% (sham) of the maximum inspiratory pressure (Pimax). Main outcomes: Functional capacity, diaphragm hypertrophy, respiratory muscle strength, lung volume, blood pressure and quality of life. Statistical Analysis: Presentation of data in absolute and relative numbers, and through means and standard deviations. To compare the groups, ANOVA will be used, with significance less than 0.05.

intradialytic training, Inspiratory Muscle Training, Diaphragm Hypertrophy, Functional capacity, End Stage Kidney Disease

IMT intervention: IMT50 - 50% of the maximum inspiratory pressure (MIP), using equipment "Threshold IMT®" or "Power Breathe®", which are respiratory incentives of linear pressure load, where the patient uses a nose clip and breathes through a mouthpiece with a resistance in the inspiratory branch, using the respective MIPs.

IMT intervention: IMT30 - 30% of the maximum inspiratory pressure, using equipment "Threshold IMT®" or "Power Breathe®", which are respiratory incentives of linear pressure load, where the patient uses a nose clip and breathes through a mouthpiece with a resistance in the inspiratory branch, using the respective MIPs.

IMT intervention: IMT10 - 10% of the maximum inspiratory pressure, using equipment "Threshold IMT®" or "Power Breathe®", which are respiratory incentives of linear pressure load, where the patient uses a nose clip and breathes through a mouthpiece with a resistance in the inspiratory branch, using the respective MIPs.

Patients will be submitted to three weekly IMT sessions in three different intensities for a period of twelve weeks, totaling 36 sessions.

The 6MWT is a useful, validated, and well-tolerated tool that requires no specialized equipment, used to determine the functional capacity of individuals with chronic kidney disease. 19 In addition, the 6MWT is able to represent the submaximal level of functional capacity (e.g., daily physical activity). The results will be defined as the difference in meters in distance covered at weeks 0 and 12. Participants will be instructed to walk on a flat, straight corridor, and will be told that the objective of the test is to walk as far as possible for six minutes at a self-selected speed.

Patients will be submitted to CPET on an exercise bike, using an incremental loading protocol according to the guidelines published by the American Thoracic Society / American College of Chest Physicians.

Mode B ultrasound (EnVisor C, Philips, Bothell, Washington) with a 12.0 MHz ultrasound probe (L12-3, Philips) will be used for the image of the diaphragm in the apposition zone, the vertical section that rests against the lateral portion of the right rib cage, with the method described by Wait et al.

ABPM is a method that allows indirect and intermittent blood pressure recordings for a period of 24 hours, while patients perform their daily life activities.

Maximal Inspiratory Measure and Maximal Expiratory Measure: will be carried out by GlobalMed® MVD300 manovacuometry equipment.

Inclusion Criteria: CKD patients who have been on HD for at least three months; In physical conditions to perform the tests proposed by the study; With stable CKD for at least 30 days (with no hospitalization); Exclusion Criteria: Patients with a recent history of arrhythmias; Recent hospitalization (<3 months); Recent acute myocardial infarction (<6 weeks); HD routine less than 2X / week; Muscle or respiratory changes (eg, chronic obstructive pulmonary disease (COPD)); Unstable angina; Severe valve disease; Uncontrolled hypertension; Hemoglobin concentration <10 g / dL; Participation in a study with intradialytic exercise in the six months preceding this study; Refusal to participate in the study.