Maximal Dynamic Inspiratory Pressure Evaluation in Heart Failure: A Comprehensive Reliability and Agreement Study

Area of Science:

• Cardiology
• Pulmonology
• Rehabilitation Medicine

Background:

• Heart failure (HF) impacts respiratory muscle function.
• Assessing inspiratory muscle strength is crucial for HF management and rehabilitation.
• Existing measurement tools may have limitations in reliability and agreement.

Purpose of the Study:

• To evaluate the reliability (interrater and intrarater) and agreement (repeatability and reproducibility) of tapered flow resistive loading (TFRL) for measuring maximal inspiratory pressure (MIP) and S-Index in heart failure patients.

Main Methods:

• A cross-sectional study involving 124 heart failure patients.
• Maximal inspiratory pressure (MIP) measured using a standard manovacuometer (SM) and TFRL.
• S-Index (maximal dynamic inspiratory pressure) measured using TFRL.
• Interrater and intrarater reliability assessed by two evaluators.
• Repeatability assessed over 10 maneuvers.
• Reproducibility compared between SM and TFRL.

Main Results:

• High interrater (ICC=0.89) and intrarater (ICC=0.97) reliability for the S-Index using TFRL.
• Eight maneuvers were needed for stable S-Index measurement in 75.81% of patients.
• Reproducibility of TFRL measures (S-Index, MIP) was similar to standard manovacuometer (MIP).

Conclusions:

• TFRL is a reliable and repeatable method for assessing S-Index in heart failure patients.
• TFRL demonstrates acceptable repeatability, requiring approximately 8 maneuvers for stable measurements.
• The reproducibility of TFRL measures is comparable to traditional methods, indicating its clinical utility.