title: Diagnostic methods to assess inspiratory and expiratory muscle strength.
abstract: Impairment of (inspiratory and expiratory) respiratory muscles is a common clinical finding, not only in patients with neuromuscular disease but also in patients with primary disease of the lung parenchyma or airways. Although such impairment is common, its recognition is usually delayed because its signs and symptoms are nonspecific and late. This delayed recognition, or even the lack thereof, occurs because the diagnostic tests used in the assessment of respiratory muscle strength are not widely known and available. There are various methods of assessing respiratory muscle strength during the inspiratory and expiratory phases. These methods are divided into two categories: volitional tests (which require patient understanding and cooperation); and non-volitional tests. Volitional tests, such as those that measure maximal inspiratory and expiratory pressures, are the most commonly used because they are readily available. Non-volitional tests depend on magnetic stimulation of the phrenic nerve accompanied by the measurement of inspiratory mouth pressure, inspiratory esophageal pressure, or inspiratory transdiaphragmatic pressure. Another method that has come to be widely used is ultrasound imaging of the diaphragm. We believe that pulmonologists involved in the care of patients with respiratory diseases should be familiar with the tests used in order to assess respiratory muscle function.Therefore, the aim of the present article is to describe the advantages, disadvantages, procedures, and clinical applicability of the main tests used in the assessment of respiratory muscle strength.
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Respiratory Muscle Research Group, Pulmonary Division, Instituto do Coração - Incor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Pedro
authors.initials: P
authors.lastname: Caruso
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Respiratory Muscle Research Group, Pulmonary Division, Instituto do Coração - Incor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: André Luis Pereira de
authors.initials: AL
authors.lastname: Albuquerque
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Respiratory Muscle Research Group, Pulmonary Division, Instituto do Coração - Incor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Pauliane Vieira
authors.initials: PV
authors.lastname: Santana
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Respiratory Muscle Research Group, Pulmonary Division, Instituto do Coração - Incor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Leticia Zumpano
authors.initials: LZ
authors.lastname: Cardenas
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Respiratory Muscle Research Group, Pulmonary Division, Instituto do Coração - Incor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Jeferson George
authors.initials: JG
authors.lastname: Ferreira
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Respiratory Muscle Research Group, Pulmonary Division, Instituto do Coração - Incor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Elena
authors.initials: E
authors.lastname: Prina
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Respiratory Muscle Research Group, Pulmonary Division, Instituto do Coração - Incor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Patrícia Fernandes
authors.initials: PF
authors.lastname: Trevizan
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Respiratory Muscle Research Group, Pulmonary Division, Instituto do Coração - Incor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Mayra Caleffi
authors.initials: MC
authors.lastname: Pereira
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Respiratory Muscle Research Group, Pulmonary Division, Instituto do Coração - Incor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Vinicius
authors.initials: V
authors.lastname: Iamonti
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Respiratory Muscle Research Group, Pulmonary Division, Instituto do Coração - Incor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Renata
authors.initials: R
authors.lastname: Pletsch
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Respiratory Muscle Research Group, Pulmonary Division, Instituto do Coração - Incor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Marcelo Ceneviva
authors.initials: MC
authors.lastname: Macchione
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Pulmonary Division, Instituto do Coração - Incor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Carlos Roberto Ribeiro
authors.initials: CR
authors.lastname: Carvalho
mesh_terms: D045853:Exhalation / Q000502:physiology; D006801:Humans; D001239:Inhalation / Q000502:physiology; D007320:Inspiratory Capacity; D009055:Mouth; D053580:Muscle Strength / Q000502:physiology*; D009468:Neuromuscular Diseases / Q000175:diagnosis*; D011312:Pressure; D012129:Respiratory Function Tests / Q000379:methods*; D012132:Respiratory Muscles / Q000503:physiopathology*
keywords: Diagnostic tests, routine; Diaphragm; Muscle weakness; Respiratory function tests; Respiratory muscles