Safety, Feasibility, and Impact of Preoperative Respiratory Strength Training in Cardiac Surgical Patients

Enrolled research participants will undergo baseline assessments of pulmonary function: maximum expiratory pressure (MEP), maximum inspiratory pressure (MIP), cough function (voluntary PEF and cough spirometry), and will complete self-reported dyspnea using the validated London Chest Activity of Daily Living (LCADL) scale. Following baseline testing, participants will complete a respiratory strength training program (RST) in the home via telehealth with one in-person home therapy session conducted at each participant's midpoint to reassess MEP and MIP and to recalibrate the respiratory strength trainer devices. After the prescribed RST program, participants will complete a second post-RST preoperative assessment. All pulmonary function measures will be performed by a research SLP in accordance with standardized protocols and guidelines from the American Thoracic Society 12-14 with research participants in an upright seated position with nose clips in place. A swallowing examination (FEES) will be completed both pre and post surgery to assess any impact on swallowing safety.

Respiratory Assessment:

MEP and MIP measurements will be obtained using a MicroRPM handheld menometry device (MicroDirect). For MEP testing, research participants will be instructed to take a deep breath in, place their mouth around the mouthpiece, and blow out as forcefully as possible. As needed, the research SLP will assist with lip seal by holding the sides of participant's cheeks to prevent air leakage. For MIP testing, research participants will be instructed to expel all the air out of their lungs, place their mouth around the mouthpiece, and breathe in as forcefully as possible. Each participant will perform 3 MEP and MIP trials. Average MEP and MIP values will be used to calibrate expiratory and inspiratory devices and for subsequent analyses.

Respiratory Strength Training (RST) Program:

The RST program consists of expiratory muscle strength training (EMST) and inspiratory muscle strength training (IMST) using the EMST-75 Lite or the EMST-150 and the IA-150 devices (Aspire Products), respectively. Trainer devices will be calibrated to a 50% load of individualized MEP and MIP values. The CS patients will perform 25 repetitions each (5 sets of 5 repetitions) of the expiratory and inspiratory exercises, 5 days/week leading up to their surgical procedure. The patients will be given training logs to track completion of the RST exercises to measure adherence.