Predictive equations for respiratory muscle strength according to international and Brazilian guidelines

Abstract

Background: The maximum static respiratory pressures, namely the maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP), reflect the strength of the respiratory muscles. These measures are simple, non-invasive, and have established diagnostic and prognostic value. This study is the first to examine the maximum respiratory pressures within the Brazilian population according to the recommendations proposed by the American Thoracic Society and European Respiratory Society (ATS/ERS) and the Brazilian Thoracic Association (SBPT). Objective:To establish reference equations, mean values, and lower limits of normality for MIP and MEP for each age group and sex, as recommended by the ATS/ERS and SBPT. Method:We recruited 134 Brazilians living in Belo Horizonte, MG, Brazil, aged 20-89 years, with a normal pulmonary function test and a body mass index within the normal range. We used a digital manometer that operationalized the variable maximum average pressure (MIP/MEP). At least five tests were performed for both MIP and MEP to take into account a possible learning effect. Results:We evaluated 74 women and 60 men. The equations were as follows: MIP=63.27-0.55 (age)+17.96 (gender)+0.58 (weight), r2 of 34% and MEP= - 61.41+2.29 (age) - 0.03(age2)+33.72 (gender)+1.40 (waist), r2 of 49%. Conclusion: In clinical practice, these equations could be used to calculate the predicted values of MIP and MEP for the Brazilian population.

Frequência de sucesso de pré-escolares e escolares com e sem sintomas respiratórios nos testes de função pulmonar

“…To avoid air leaking, individuals were asked to keep the mouthpiece firm around the lips 1,9 . The test was conducted in a sitting position, with the feet on the ground, and using a nasal clip 1,12 . Before measuring the maximum respiratory pressure, evaluators demonstrated in detail the execution of the maneuvers.…”

“…The latter has the objective of quantifying the inspiratory and expiratory muscle strength, responsible for the functioning of ventilatory mechanics 10 . Several studies have been published with the aim of generating reference values for the spirometry and manovacuometry tests in children and adolescents 9,[11][12][13][14] , to standardize and facilitate the interpretation of ventilatory findings obtained in these tests. Although studies report that the age factor has direct influence on the success of these methods and that the quality of the tests can be compromised in children under 12 years of age, information on the success rate of these resources in the pediatric age group are still scarce, especially for the manovacuometry test.…”

Análise comparativa da força dos músculos respiratórios em indivíduos saudáveis no solo e na piscina

“…They involve objective measures to diagnose various diseases 4 . Manovacuometry is a simple, non-invasive and easy-to-apply resource 5 used to assess respiratory pressures, which reflect the respiratory muscle strength 6 .…”

Predictive equations for respiratory muscle strength by anthropometric variables

“…It is simple, safe and noninvasive widely used in clinical practice but subject to the imprecision of the evaluations for being a volitional test, and so the diagnosis can be wrong. [4][5][6] After pioneering the study by Black and Hyatt (1969), the first major impact on reference values, 1 facing methodological differences, some discussions were raised about the variability and usefulness of Maxims Respiratory Pressures tests (MRP), which implied the absence of consensus, and therefore devaluation of in the technique. 6,7 Nowadays, the…”

“…search for standardized protocols, and especially reproducible and applicable values have guided research in this area. 6,8 There is a consensus that many individual factors can interfere with MRP, such as sex, age, height, weight, muscle work capacity and physical fitness, lung volume that were made the measures and the corresponding value of elastic recoil pressure of the respiratory system, smoking, level of education and the individuals own motivation [4][5][6][9][10][11] ; however, the influence of certain individual factors, such as height and weight, is still controversial. [12][13][14] In most studies, sex and age are observed as the two variables that most commonly used as predictors of maximal respiratory pressures.…”