Inspiratory Muscle Training and Pulmonary Function in Patients Submitted to Bariatric Surgery

Pre-operative Inspiratory Muscle Training Effectiveness and Pulmonary Function in Patients Submitted to Bariatric Surgery

Obesity is defined as a body mass index greater than or equal to 30 kg / m2 and represents a public health problem that affects the world population. Because it affects several organ systems, obesity is associated with a higher frequency of cardiovascular, metabolic diseases, and respiratory morbidities, which substantially affect the quality of life of patients. The treatment of obesity comprises different strategies, however, in view of the little success with more conventional treatments, surgical treatment has been the most sought after today. Objectives: To evaluate the effectiveness of preoperative inspiratory muscle training in the evolution of respiratory muscle strength in patients undergoing bariatric surgery. Methodology: Randomized clinical trial. All patients will be assessed in the pre operative period and randomized into 2 groups: control group and intervention group. The main variables are maximum inspiratory and expiratory muscle strength (MIP and MEP), peak cough flow (PCF) and pain. Control group will perform proposed respiratory physiotherapy, aerobic exercises and use of incentive inspirometry, the intervention group will perform proposed physiotherapy, aerobic exercises and use of Powerbreathe for inspiratory muscle training. Both groups will perform 10 non consecutive face-to-face physiotherapy sessions ( up 30 days before surgery). After the surgical intervention, they will be evaluated on the first and 30th postoperative days in relation to the same variables and pulmonary complications. Statistical Analysis: Sample calculation performed through a previous study: 42 patients per group. After the intervention, they will be evaluated on the second postoperative day for days of hospitalization and pulmonary complications. Statistical Analysis: Sample calculation performed through a previous study: 42 patients per group. After the intervention, they will be evaluated on the second postoperative day for days of hospitalization and pulmonary complications. Statistical Analysis: Sample calculation performed through a previous study: 42 patients per group. Categorical variables will be summarized in absolute and relative frequencies (percentages). Information regarding numerical variables will be expressed as means, standard deviations or medians, and interquartile range, depending on the distribution of the variable. All variables will be tested in relation to their distribution. To analyze the results between groups will be used the mixed linear models and for intragroup analysis, two-way ANOVA (time and group) for the following variables: MIP and MEP, PCF and pain. Expected results: Preoperative inspiratory muscle training can maintain/improve respiratory muscle strength until the moment prior to surgery, thus better preparing the patient for the condition of surgical stress, in addition to decreasing the incidence of pulmonary complications during the hospitalization period and / or in the 30 postoperative days.

bariatric surgery, respiratory muscle strength, pulmonary function, preoperative, postoperative complications

The control group will receive an aerobic exercise in the cycle ergometer that will be conducted on a cycle ergometer divided into three steps: heat 5 minutes; 20 minutes with a confortable speed ( individuallyprescribed) and 5 minutes recovery. They will also perform active respiratory exercises, and incentive spirometer during 10 face-to-face physical therapy sessions. They will be instructed to do exercises with incentive spirometer at home, 3 times a day with 30 to 40 repetitions, during all preoperative period. The patients will receive a diary to note the exercises frequency.

This intervention group will receive the same control group protocol: aerobic exercise in cycle ergometer, divided into three steps: heat 5 minutes; 20 minutes with a confortable speed ( individually prescribed) and 5 minutes recovery and active respiratory exercises ( deep inspirations associated to raise upper limbs ( 3 times of 10 repetitions each), and, in addition, inspiratory muscle training with Powerbreath during 10 face-to-face physical therapy sessions. They will be instructed to do exercises with Powerbreath at home, 3 times a day with 30 to 40 repetitions, inspiratory load: 60% of MIP ( first evaluation - protocol admission) during all preoperative period. The patients will receive a diary to note the exercises frequency.

The device "Powerbreath" is an inspiratory muscle training used to train respiratory muscles. Currently, it is one of the most used devices for the TMI, a linear load model with continuous application of inspiratory pressure throughout inspiration, in which the inspiratory regulating valve remains open while allowing an unrestricted expiration that generates resistance through a spring or of an electronic valve system, ability to offer greater load during training.

10 face-to-face non consecutive sessions with 30 minutes in a cycle ergometer(divided into three steps: heat 5 minutes; 20 minutes with a comfortable and supportable speed or load ( individually prescribed) and 5 minutes recovery

Diaphragmatic exercises ( deep inspirations) associated to raise upper limbs ( 3 times - 10 repetitions each)

To measure MIP, patients will be instructed to perform a maximal inspiratory effort from residual volume (RV), using a previously calibrated analog manovacuometer (range +/- 300cmH20). The highest value obtained after three repetitions will be recorded. The obtained values will be compared to the predicted values ( Predicted equations by Neder et al.)

All patients will be assessed at baseline ( protocol admission), in the 10th session of preoperative protocol ( average 30 days), 1st postoperative day ( average 7 days after the last pre op.session) and 30th postoperative day ( 30 days after surgery)

To measure MEP, patients will be instructed to perform a maximal expiratory effort from total lung capacity (TLC) using a previously calibrated analog manovacuometer (range +/- 300cmH20). The highest value obtained after three repetitions will be recorded. The obtained values will be compared to the predicted values ( Predicted equations by Neder et al.)

All patients will be assessed at baseline ( protocol admission), in the 10th session of preoperative protocol ( average 30 days), 1st postoperative day ( average 7 days after the last pre op.session) and 30th postoperative day ( 30 days after surgery)

For PCF measurements, you will be asked to the patients to cough with maximum effort after a deep inspiration using a peak flow meter. The highest value obtained from three repetitions will be recorded. The obtained values will be compared to the predicted values for healthy Brazilian population.

All patients will be assessed at baseline ( protocol admission), in the 10th session of preoperative protocol ( average 30 days), 1st postoperative day ( average 7 days after the last pre op.session) and 30th postoperative day ( 30 days after surgery)

The pain will be measured by visual numeric scale (VNS). The scale ranges from 0 to 10, with 10 being the worst possible pain.

All patients will be assessed at baseline ( protocol admission), in the 10th session of preoperative protocol ( average 30 days), 1st postoperative day ( average 7 days after the last pre op.session) and 30th postoperative day ( 30 days after surgery)

Inclusion Criteria: Accept to participate in the study Age over 18 years Any gender Elective bariatric surgery Exclusion Criteria: Mechanical ventilation for more than 48 hours after the surgical procedure Hemodynamic instability at the time of the first evaluation and persistent in the evaluation after 1 hour