Inspiratory Muscle Strength in Chagas Cardiomyopathy: A Systematic Scoping Review

ABSTRACT The increase in inflammatory markers associated with persistent chronic fibrosing myocarditis, a characteristic of chronic Chagas disease, can result in a reduction in inspiratory muscle strength (IMS) in Chagas cardiomyopathy (CC). However, literature in this field is still scarce. This review aimed to map and summarize the evidence regarding IMS in patients with CC. The inclusion criteria included reports with adult participants with a CC diagnosis, with or without heart failure (HF). The core concept examined was the maximum inspiratory pressure evaluated in the untrained and trained groups in the pre-training period. The context was open, including but not limited to hospitals and health centers. Two authors independently identified eligible studies and extracted the data. Descriptive synthesis was used as the primary strategy for analyzing the results. Nine studies (five clinical trials, three cross-sectional, and one cohort) were included. The CC classification differed among the studies, with no mention of HF in five and no CC staging specification in six. IMS was assessed using a manovacuometer, and only six studies analyzed and interpreted the data concerning the predicted values. The CC population with HF appeared to have impaired IMS. All studies involved only Brazilian volunteers. In conclusion, randomized clinical trials evaluating IMS and the effects of inspiratory muscle training need to be conducted to better understand the prevalence and risk of inspiratory muscle weakness in the CC population, as well as the effects of training. Such studies should be conducted at different stages of CC in different populations and countries.

The effects of inspiratory muscle fatigue on subsequent high-intensity exercise performance and muscle tissue oxygenation / 体力科学

It has been suggested that inspiratory muscles fatigue impairing blood flow to the active limb muscle via respiratory muscle metaboreflex. The purpose of this study was to investigate the effects of inspiratory muscle fatigue on exercise performance and muscle tissue oxygenation in high-intensity exercise takes about 3.5~5min. Eleven healthy males subjects performed two conditions of constant-load exercise to exhaustion (TTE) on a cycle ergometer at 100% of maximal oxygen uptake. The two conditions—inspiratory muscle fatiguing (IMF) and non-fatiguing (PLA) —which had different intensity inspiratory resistance breathing (IRB) were performed before exercise. Muscle tissue oxygenations were measured by deoxyhemogrobin (HHb), oxygen saturation index (StO2) from right vastus lateralis during TTE. All data were analyzed from nine subjects whose inspiratory muscle were fatigued by IRB in IMF. Results: TTE was significantly shorter in IMF compare to PLA (244±31s vs. 268±38s, p<0.05). HHb was significantly higher and StO2 was significantly lower in IMF than in PLA (p<0.05). Conclusion: High-intensity exercise completed in 3.5~5 minutes, it was suggested that inspiratory muscle fatigue reduced the oxygen deriver to active limb muscle, resulting in decrease exercise performance. Improving function of inspiratory muscles, such as in inspiratory muscle training, may improve oxygenation of the active limb muscle and enhance exercise performance.

Predictive equations for ventilatory muscle strength in the Brazilian population: a systematic review / Equações preditivas da força muscular ventilatória na população brasileira: uma revisão sistemática / Ecuaciones predictivas de la fuerza muscular respiratoria en la población brasileña: una revisión sistemática

ABSTRACT Maximal inspiratory and expiratory pressures (MIP and MEP) assess the strength index of the respiratory muscles. These measures are relevant to assess respiratory muscle strength and for clinical monitoring. This study evaluates papers that suggest predictive equations of MIP and MEP for the Brazilian population. We included studies that established prediction equations for MIP and MEP for the healthy Brazilian population, aged from 4 to 90 years old, both men and women and that had the maximum respiratory pressures measured in a sitting position. A search was carried out in March 2020 on MEDLINE, LILACS, Cochrane, SciELO, CINAHL, Web of Science, and SCOPUS databases, without date or language filters. The descriptors used were "muscle strength," "equations," "predictive respiratory muscles" and their respective synonyms. Out of the 3,920 studies found in databases, 963 were duplicates, 2,779 were excluded, 178 had their full texts analyzed, and only 9 met the inclusion criteria. The predictive equations of ventilatory muscle strength analyzed in this review used age, weight, and stature as variables. However, the studies showed methodological weaknesses, such as lack of cross-validation of the equation, exclusion of outliers, and lack of familiarization of MIP and MEP.

RESUMO As pressões respiratórias máximas (PImáx e PEmáx) avaliam o índice de força dos músculos respiratórios. Essas medidas são relevantes para a avaliação da força muscular respiratória e para o monitoramento clínico. O objetivo deste estudo foi avaliar os artigos que sugerem equações preditivas de PImáx e PEmáx para a população brasileira. Foram incluídos estudos que estabeleceram equações de predição para PImáx e PEmáx da população brasileira saudável, com idades entre 4 e 90 anos e de ambos os sexos, que mediam as pressões respiratórias máximas na posição sentada. Uma pesquisa foi realizada, em março de 2020, nas bases de dados MEDLINE, LILACS, Cochrane, SciELO, CINAHL, Web of Science e SCOPUS, sem filtros de tempo ou idioma. Os descritores utilizados foram "força muscular", "equações" e "músculos respiratórios preditivos", com seus respectivos sinônimos. Dos 3.920 estudos encontrados nas bases de dados, 963 eram duplicados e 2.779 foram excluídos, 178 tiveram seus textos analisados integralmente e apenas 9 atendiam aos critérios de inclusão. As variáveis utilizadas nas equações preditivas de força muscular ventilatória analisadas nesta revisão foram: idade, peso e estatura. No entanto, os estudos mostraram fragilidades metodológicas, como falta de validação cruzada da equação, exclusão de outliers e familiarização do PImáx e PEmáx.

RESUMEN Las presiones inspiratoria y espiratoria máximas (PImáx y PEmáx) evalúan el índice de fuerza muscular respiratoria. Estas medidas son importantes en la evaluación de la fuerza muscular respiratoria y el seguimiento clínico. El objetivo de este estudio fue evaluar los artículos proponen ecuaciones predictivas para PImáx y PEmáx a la población brasileña. Se incluyeron estudios que establecieron ecuaciones predictivas para PImáx y PEmáx a la población brasileña sana de ambos sexos, de entre 4 y 90 años de edad, y que miden las presiones respiratorias máximas en posición sentada. Se realizó, en marzo de 2020, una búsqueda en las bases de datos MEDLINE, LILACS, Cochrane, SciELO, CINAHL, Web of Science y SCOPUS, sin año de publicación específico ni idioma. Los descriptores utilizados fueron "fuerza muscular", "ecuaciones" y "músculos respiratorios predictivos" y sus respectivos sinónimos. De los 3.920 estudios encontrados, 963 eran duplicados y se excluyeron 2.779, así se analizaron 178 textos en su totalidad y solo 9 cumplieron con los criterios de inclusión. Las variables edad, peso y talla fueron las que habían sido utilizadas en las ecuaciones predictivas de fuerza muscular respiratoria analizadas por esta revisión. Sin embargo, los estudios apuntaron limitaciones metodológicas, como falta de validación cruzada de la ecuación, exclusión de outliers y familiaridad de la PImáx y PEmáx.

Assessment of ventilatory function in patients with spinocerebellar ataxia type 2 / Avaliação da função ventilatória em pacientes com ataxia espinocerebelar tipo 2

Abstract Subclinical ventilatory dysfunction is observed in individuals with spinocerebellar ataxias (SCA). No studies have correlated ventilatory dysfunction to clinical and functional decline in SCA2. Objective: To evaluate the relationship between the values of peak expiratory flow (PEF), maximum inspiratory pressure (MIP), and presence of respiratory complaints with age, disease duration, age at onset of symptoms, balance scores, independence in basic (ADL) and instrumental (IADL) Activities of Daily Living (ADLs), and severity of ataxia (SARA) in individuals with SCA2. Methods: Cross-sectional study evaluating age, disease duration, age at onset of symptoms, scores in the Berg Balance Scale and in the SARA, Functional Independence Measure and Lawton's scale, values of PEF and MIP, and the presence of respiratory complaints. Results: The study included 36 individuals with SCA2, with a mean age of 42.5±2.4 years, disease duration of 7.6±8.2 years, age 33.7±11.5 years at onset of symptoms, and 9.9±10.3 points in the SARA scale. The lowest PEF values correlated with the longer disease duration (p=0.021). The lowest values of PEF and MIP correlated with greater balance impairment (p=0.019 and p=0.045, respectively), increased degree of dependence in the ADL (p=0.006 and p=0.050, respectively) and IADL (p=0.003 and p=0.001, respectively) scales, and highest severity of ataxia (p=0.00 and p=0.017, respectively). Respiratory complaints were observed in 12 (33.3%) individuals and were not related to age, disease duration, age at onset of symptoms, balance, independence, ataxia severity, or PEF and MIP values. Conclusion: Ventilatory dysfunction, even when asymptomatic, is related to balance impairment, independence, and ataxia severity in individuals with SCA2.

Resumo Disfunção ventilatória subclínica tem sido observada em indivíduos com ataxias espinocerebelares (SCA). Não existem estudos relacionando disfunção ventilatória ao declínio clínico e funcional na SCA2. Objetivo: Avaliar a relação dos valores de Pico de Fluxo Expiratório (PFE), Pressão Inspiratória Máxima (PIMAX) e presença de queixas respiratórias com idade, tempo de doença, idade de início dos sintomas, escore de equilíbrio, independência para atividades básicas (AVD) e instrumentais (AIVD) de vida diária e gravidade da ataxia (SARA) em indivíduos com SCA2. Métodos: Estudo transversal, considerando: idade, tempo de doença, idade de início dos sintomas, escores nas Escalas SARA, Equilíbrio de Berg, Medida da Independência Funcional e de Lawton, valores de PFE, PIMAX e queixas respiratórias. Resultados: Foram avaliados 36 indivíduos com SCA2 com média de 42,5±2,4) anos de idade, 7,6±8,2 anos de tempo de doença, 33,7±11,5 anos de idade de início dos sintomas e 9,9±10,3 pontos na escala SARA. Os menores valores de PFE estiveram relacionados ao maior tempo de doença (p=0,021). Os menores valores de PFE e PIMAX estiveram relacionados ao maior comprometimento do equilíbrio (p=0,019; p=0,045, respectivamente), maior dependência para ADV (p=0,006; p=0,050, respectivamente) e AIVD (p=0,003; p=0,001, respectivamente) e maior gravidade da ataxia (p=0,006; p=0,017, respectivamente). Foram observadas queixas respiratórias em 12 (33,3%) indivíduos que não estiveram relacionadas à idade, idade de início dos sintomas, tempo de doença, equilíbrio, independência, gravidade da ataxia, ou valores de PFE e PIMAX. Conclusão: A disfunção ventilatória, mesmo quando assintomática, está relacionada ao comprometimento do equilíbrio, à independência e à gravidade da ataxia em indivíduos com SCA2.

Correlação entre pressão plantar e força muscular respiratória / Correlation between plantar pressure and respiratory muscle strength

Existem evidências de que alterações posturais possam influenciar no funcionamento da caixa torácica. Além disso, para uma respiração adequada, é necessária boa postura e equilíbrio muscular. O objetivo do presente estudo foi verificar se existe correlação entre a pressão plantar e a força muscular respiratória, visto que ambas sofrem interferência das alterações posturais. Foram avaliados 30 funcionários de uma instituição de Ensino Superior do Médio Paraíba, com idade média de 43,43 ± 13,29 anos, subdivididos em 2 grupos: Grupo experimental (I) e Grupo Controle (II). O grupo I foi submetido a 30 sessões de treinamento muscular respiratório; e ao final da intervenção, ambos os grupos foram reavaliados. Os resultados mostraram que algumas pressões plantares sofreram interferência significativa, com p < 0,05 da força muscular respiratória (PImáx e PEmáx), após o protocolo de exercício, confirmando nossa hipótese sobre a possível associação entre a força muscular respiratória e a pressão plantar, pela correlação positiva apresentada por algumas variáveis avaliadas. (AU)

There are evidences that postural alteration may influence the functioning of the thoracic cage. However, proper breathing requires good posture and muscle balance. The present study aim was to verify whether there is correlation between a plantar pressure and respiratory muscle strength, as both suffer interference of the postural alterations. We evaluated 30 employees from an a higher Education Institution with the average age between 43,43 ± 13,29 years subdivided into two groups: Experimental group (I) and Control group (II). Group I underwent 30 sessions of respiratory muscle training and at the end of the intervention both groups were reevaluated. The results showed that some plantar pressures undergo significant interference with p < 0.05 in respiratory muscle strength (PEmáx e PEmáx) after exercise protocol confirming our hypothesis about the possible association between respiratory muscle strength and plantar pressure by the positive correlation presented by some variables evaluated. (AU)

Efecto del entrenamiento de la musculatura inspiratoria con válvula umbral sobre la capacidad funcional en mujeres físicamente activas mayores de 60 años / Effect of inspiratory muscle training with threshold valve on functional capacity of physically active women who are older than 60 years of age

Resumen Introducción: Los cambios fisiológicos asociados al envejecimiento generan una serie de modificaciones funcionales, destacando una disminución en la capacidad respiratoria. En este sentido, una estrategia alternativa para mejorar tal condición podría ser el entrenamiento de la musculatura inspiratoria (EMI). Objetivo: Analizar el efecto del EMI con válvula umbral, sobre la capacidad funcional en mujeres físicamente activas mayores de 60 años. Materiales y métodos: Se realizó un EMI con válvula umbral durante 4 semanas, sobre un grupo experimental (GE; n:10), contrastado con un grupo control (GC; n:5). Se valoraron las siguientes variables hemodinámicas y antropométricas: peso, talla, índice de masa corporal (IMC), lactato, doble producto y capacidad funcional, analizando los cambios pre y post entrenamiento. Resultados: en el grupo GE disminuye post intervención la concentración de lactato y la escala de percepción del esfuerzo; 3,16±0,51 a 2,5±0,39 y 5,56 ± 1,81 a 4±2, respectivamente. En el mismo grupo se incrementan los valores de presión inspiratoria máxima (Pimáx) post intervención; 42,11±14,57 a 60,44±14,47. El GC no presentó cambios en sus valores. Conclusión: No se evidencian cambios favorables en los metros recorridos post intervención, sin embargo, el EMI mostró una disminución sobre la concentración de lactato post ejercicio, lo que podría identificar un retraso en la aparición de la fatiga.

Abstract Introduction: Physiological changes associated with aging generate a series of functional modifications, mainly a decrease in respiratory capacity. In this regard, an alternative strategy to improve such a condition could be inspiratory muscle training (IMT). Objective: To analyze the effect of IMT with threshold valve on the functional capacity of physically active women who are older than 60 years of age. Materials and methods: IMT with threshold valve was carried out over a period of 4 weeks, comparing data from the experimental group (GE; n:10) to the control group (GC; n:5). The following hemodynamic and anthropometric variables were assessed: weight, height, body mass index (BMI), lactate, double product (DP) and functional capacity. Pre and post training changes were evaluated. Results: The GE group showed a decrease in both post-intervention lactate concentration (from 3.16±0.51 to 2.5±0.39) and effort perception scale (from 5.56 ± 1.81 to 4±2). On the other hand, this group experienced a post-intervention increase in maximal inspiratory pressure (MIP) from 42.11±14.57 to 60.44±14.47. The GC group did not present changes in its values. Conclusion: Although no evidence was found regarding favorable changes in the walked distance post-intervention, IMT induced a reduction in post-exercise lactate concentration, which could indicate a delay of onset of fatigue.

Assessment Of Respiratory Muscle Strength Using Maximal Inspiratory Pressure And Maximal Expiratory Pressure In Patients With Chronic Obstructive Pulmonary Disease: A Study On Indian Population

Chronic Obstructive Pulmonary Disease (COPD) is a common disease seen in Indian population. It is most commonly seen in the lower strata where beedi and cigarette smoking is most prevalent and starts at an early age. Smoke arising from cooking stoves during cooking is the cause of COPD in females. Though the number of males suffering from COPD is much larger than females, we observed a proportionate number of females in all age group suffering from this disease. It is the leading cause of mortality and should be studied in detail so as to avoid complications in such patients. We have studied the strength of respiratory muscles in such patients using newer techniques like Maximal Inspiratory Pressure (MIP) and 7 8 Maximal Expiratory Pressure (MEP). Terzano et al. (2008) and Khalil et al.(2014) have carried out similar studies in COPD patients. We have checked correlation between anthropometric measurements and strength of respiratory muscles, correlation between airway resistance and muscle strength and also compared the sensitivity and specificity of this technique using ROC (receiver operating Curve) as compared to the age old spirometry. These techniques may help in monitoring the status of COPD patients and assessing muscle weakness.

Incubadora neonatal con ventilación mecánica embebida / Mechanical Ventilation embedded in Neonatal Incubator

RESUMEN Se presenta un equipo de soporte de vida neonatal (ESVIN) que emplea la terapia térmica y terapia ventilatoria (neumática) en un solo equipo para proveer ventilación pulmonar con aire caliente, humedecido y enriquecido con oxígeno, en un ambiente caliente, humidificado y estéril. El equipo es capaz de simultáneamente dar ventilación pulmonar e incubar, siendo una de sus características principales la minimización de la condensación del agua en el corrugado y ofrece la característica adicional de evitar la movilización y/o desconexión del neonato para realizar ciertos procedimientos tales como: cirugías e intubaciones, entre otras. Los principales resultados son el tiempo de acceso al neonato menor a 2 s y minimización de la condensación de agua. Asimismo, los resultados del control térmico son de tiempo de estabilización en el habitáculo de 75 minutos para la temperatura de 36 °C y tiempo de estabilización de la temperatura de la piel del neonato de 58 minutos.

ABSTRACT A neonatal life support equipment (ESVIN) employing simultaneously thermal therapy and ventilatory (pneumatic) therapy is presented in a single kit to provide pulmonary ventilation with warm, moistened and oxygen enriched air in a warm, humidified and sterile environment. The invention behind ESVIN provided simultaneously pulmonary ventilation and incubation having optimized the minimization of water condensation in the corrugated pipe and offered the additional feature of avoiding the mobilization and / or disconnection of the neonate to perform certain procedures such as: surgeries and intubations, among others. ESVIN has an access to newborns of less than 2 s and non-visible water condensation. The main results in thermal control were a stabilization time in the newborn compartment of 75 minutes for the temperature of 36 °C and a stabilization of the temperature of the skin of the neonate of 58 minutes.

The Effect of Pneumoperitoneum and Trendelenburg position on respiratory mechanics under general anesthesia during gynecological laparoscopic surgery / Монголын Анагаах Ухаан

Background@#Gynecological laparoscopic surgery requires pneumoperitoneum(PP) with CO₂ gas insufflation and Trendelenburg position. Pneumoperitoneum and Trendelenburg position may impact intraoperative respiratory mechanics in anesthetic management.The goal of this study was to evaluate the influence of Pneumoperitoneum and Trendelenburg position on respiratory mechanics and ventilation. @*Methods@#Twenty one patients scheduled for elective gynecological laparoscopy were evaluated. The patients had no preexisting lung and heart disease or pathologic lung function. Conventional general anesthesia with thiopental sodium, fentanyl, аtracrium and isoflurane was administered. The peak inspiratory pressure, plateau pressure, and end-tidal CO₂ were compared before after creation of pneumoperitoneum with an intraabdominal pressure of 15 mmH₂O, then after PP10, PP20, PP30 minutes in the 20° Trendelenburg position, and after deflation of pneumoperitoneum. The dynamic lung compliance was calculated.@*Results@#During of pneumoperitoneum, there were a significant increase in peak inspiratory pressure by 6 cmH₂O, plateau pressure by 5 cmH₂O, while dynamic lung compliance decreased by 11 ml/cmH₂O. General, the Trendelenburg position induced no significant hemodynamic and pulmonary changes.@*Conclusion@#The effects of pneumoperitoneum significantly reduced dynamic lung compliance and increased peak inspiratory and plateau pressures. The Tredelenburg position did not change these parameters. The end-tidal CO₂ significantly increased after pneumoperitoneum and CO₂ deflation.

Influencia del polimorfismo inserción / deleción (rs4646994) del gen de la enzima convertidora de angiotensina en la presión inspiratoria y espiratoria máxima de jóvenes chilenos sedentarios / Influence of the polymorphism insertion / deletion (rs4646994) of the angiotensin converting enzyme (ACE) gene on maximum inspiratory and expiratory pressure of Chilean sedentary youth

RESUMEN: La expresión de los genes puede impactar sobre el rendimiento muscular. En este aspecto el polimorfismo del gen de la Enzima Convertidora de Angiotensina (ECA), dependiendo de su inserción (Ins) o deleción (Del) puede potenciar diferentes cualidades musculares. Del mismo modo, si consideramos la ventilación como un proceso vital, sería relevante investigar si existe una influencia de este polimorfismo sobre los músculos que llevan a cabo tan importante función. El objetivo de este trabajo consistió en determinar el rendimiento muscular inspiratorio y espiratorio según alelos y polimorfismos del gen de la ECA. Se sometió a 83 sujetos (18 a 35 años), 46 hombres y 37 mujeres, a evaluaciones de capacidad vital forzada (CVF), presión inspiratoria máxima y presión espiratoria máxima (PIM-PEM). Posterior a esto, la genotipificación fue realizada por polimerase chain reaction (PCR) y electroforesis en gel de agarosa. Las variables fueron sometidas al análisis estadístico correspondiente según su distribución paramétrica, el nivel de significancia establecido fue un p<0,05. La distribución genotípica fue: Ins/Ins: 28 %, Ins/Del: 62 % y Del/Del: 19 %. Las mujeres homocigoto Ins, presentaron mayor PIM y PEM en modelos por genotipos (p=0,043; p=0,0001 respectivamente) y por dominancia (p=0,019; p=0,0008 respectivamente). La distribución genotípica y frecuencia alélica fue similar a la descrita anteriormente en población chilena. Además, las mujeres portadoras del alelo Ins, presentaron mayor PIM y PEM.

SUMMARY: Gene expression can impact muscle performance. In this aspect genetic polymorphism of the Angiotensin Converting Enzyme (ACE), depending on its insertion or deletion can strengthen different muscle qualities. Similarly, if we consider ventilation as a vital process, it would be important to research whether or not, there is an influence of this polymorphism on the muscles that perform such an important function. The aim of this study was to determine the inspiratory and expiratory muscle performance according alleles and polymorphisms of the ACE gene. We subjected 83 individuals (18-35 years), 46 men and 37 women, to forced vital capacity evaluations, maximum inspiratory pressure and expiratory pressure. Genotyping was subsequently performed by polymerase chain reaction (PCR) and agarose gel electrophoresis. The variables were subjected to appropriate statistical analysis by parametric distribution, the significance level was set at p <0.05. The genotype distribution was: Ins/Ins: 28 %, Ins/Del: 62 % and Del/Del: 19 %. Women homozygous Ins, exhibited a higher maximum inspiratory pressure and expiratory pressure in models for genotypes (p = 0.043; p = 0.0001 respectively) and for dominance (p = 0.019; p = 0.0008 respectively). The genotype distribution and allele frequency was similar to that described above, in Chilean population. Furthermore, women carrying the Ins allele had a higher maximum inspiratory pressure and expiratory pressure.

Efectos agudos del ciclismo indoor en la presión inspiratoria máxima (PIMax) y la presión espiratoria máxima (PEMax) de adultos activos / Acute effects of indoor cycling on maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) in active adults

Objetivo: verificar el efecto agudo del ciclismo indoor en el PIM y la PEM. Método: estudio experimental con muestra de 10 sujetos, de sexo masculino, de 20 a 30 años, practicantes de entrenamiento de ciclismo indoor durante al menos ocho semanas, con una frecuencia semanal de dos a tres veces. Las variables PIM y PEM se midieron antes y después del entrenamiento de ciclismo indoor con duración de 40 minutos, a través del método continuo. Resultados: Ambas variables mostraron una reducción significativa en comparación con los valores pre y post entrenamiento. PIM (pre: -117.5 ± 19.61; post: -110 ± 21.08) con p = 0.02, mientras que PEM (pre: 50 ± 00; post: 142.5 ± 4.8) con p = 0.01. Conclusiones: la intervención se realiza de forma continua y gradualmente creciente cuya sobrecarga puede generar adaptaciones crónicas tales como aumento de la PIM y PEM. Sin embargo, es necesario más estudios en la misma línea para verificar las relaciones y correlaciones.

Objective: To verify the acute effects of Indoor Cycling on the MIP and MEP. Method: An experimental study sample of ten male subjects, ranging in age from 20 to 30 years old, and who have practiced indoor cycling training for at least eight weeks, two to three times a week. The MIP and MEP variables were measured before and after the indoor cycling workout, lasting 40 minutes and using the continuous method. Results: Both variables showed a significant reduction when compared to pre and post training values. MIP (pre: -117.5 ± 19.61; post: -110 ± 21.08; p = 0.02) while the MEP (pre: 50 ± 00; post: 142.5 ± 4.8; p = 0.01). Conclusion: A continuous intervention with a gradual overload increase which can generate chronic adaptations such as increased MIP and MEP. However, it is necessary to carry out further studies within the same line to verify the correlation.

Análisis de presión inspiratoria máxima según tres protocolos en estudiantes voluntarios asintomáticos de la Universidad Católica del Maule, Chile / Analysis of maximal inspiratory pressure according to three protocols in asymptomatic volunteer students at the Catholic University of Maule, Chile

Maximum inspiratory pressure (MIP) has been used as an indicator of inspiratory muscle strength. Nevertheless their values show a high variability (~20%). The aim of this study was to determine the MIP, according to three protocols in young subjects. An observational cross-sectional study was carried out on a convenience sample of 60 students, 30 men (19.2 ± 0.81 years-old) and 30 women (19.17 ± 0.91 years-old). MIP was evaluated according to the protocol defined for each group of 20 participants of both genders: Group 1: American Thoracic Society/European Respiratory Society (ATS/ERS); Group 2: Learning; Group 3: Warming. For the analysis we used descriptive and inferential statistics, a p value < 0.05 was considered significant. No differences in MIP were found for the three best averages between groups (p = 0.078). When comparing the total performance of MIP replicates G3 was higher than G1 and G2 (p <0.0001). The coefficient of variation was higher in G2. It is concluded that the warming protocol (G3) could mitigate the effect of learning.

La presión inspiratoria máxima (PIM) ha sido utilizada como indicador de fuerza de la musculatura inspiratoria. No obstante sus valores presentan gran variabilidad (~20%). El objetivo del estudio fue determinar la PIM, según tres protocolos en sujetos jóvenes. Se realizó un estudio observacional de corte transversal en una muestra por conveniencia de 60 estudiantes, 30 hombres (19,2 ± 0,81 años) y 30 mujeres (19,17 ± 0,91 años). Se evaluó la PIM según el protocolo definido para cada grupo compuesto por 20 participantes de ambos géneros: Grupo 1: American Thoracic Society/European Respiratory Society (ATS/ERS); Grupo 2: Aprendizaje; Grupo 3: Calentamiento. Para el análisis se utilizó estadística descriptiva, e inferencial considerándose significativo un valor de p < 0,05. No se encontraron diferencias de PIM de los tres mejores promedios entre grupos (p = 0,078). Al comparar el desempeño total de las repeticiones de PIMG3 fue más alto que G1 y G2 (p < 0,0001). El coeficiente de variación fue más alto en G2. Se concluye que el protocolo calentamiento (G3) podría atenuar el efecto de aprendizaje.

Level of Physical Exercise Capacity, Respiratory Muscle Strength and Peak Expiratory Flow Rate in Healthy Adolescents.

Introduction: The maturation of respiratory system in children leads to changes in value of respiratory parameters like peak expiratory flow rate (PEFR), maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), and 6-minute walk distance (6MWD). Accurate analysis and clinical decisionmaking in disease state require reference values for different ages. The current study was undertaken to study pulmonary function and exercise capacity in children and adolescents. Materials and methods: After obtaining Institutional Ethical approval and parental informed consent, 262 subjects aged 9 to 15 years were recruited for the study. They were divided into two age groups, i.e., preadolescent (9-12 years) and early adolescent (13-15 years). Demographic details including age, sex, height, weight, and body mass index (BMI) were noted. Physical activity rating (PAR) scale was used to denote physical activity levels. Peak expiratory flow rate was measured using standard Mini-bell peak flow meter (PFM). The parameters MIP and MEP was measured using micro respiratory pressure meter, and 6-minute walk test (6MWT) was performed as per American Thoracic Society (ATS) guidelines. Results: A significant difference was noted between the two groups in PEFR, MIP, MEP, and 6MWD (p = 0.00). Age showed a strong positive correlation with PEFR (r = 0.613, p = 0.000), MIP (r = 0.676, p = 0.000), and MEP (r = 0.658, p = 0.00) whereas showed a strong negative correlation with 6MWD (r = -0.605, p = 0.00). Height showed a strong positive correlation with MEP (r = 0.720, p = 0.000) whereas a strong negative correlation with 6MWD (r = -0.42, p = 0.00). Weight showed a weak negative correlation with 6MWD (r = -0.328, p = 0.00). Gender difference was noticeable in 6MWD and PEFR (p = 0.00) but not in MIP (p = 0.45) and MEP (p = 0.44). Almost 22.10% of early adolescents were overweight compared to only 7.7% seen in preadolescent group. Conclusion: PEFR and respiratory muscle strength was higher in early adolescents as compared to pre-adolescents. However, exercise capacity reflected by 6 MWD was found to be lower in early adolescents in comparison to pre-adolescents. These findings could be used while interpreting the outcome measures utilized while treating patients and for goal setting in cardiopulmonary rehabilitation in clinical practice.

Effects of diaphragmatic control on the assessment of sniff nasal inspiratory pressure and maximum relaxation rate

OBJECTIVE: To assess the influence of diaphragmatic activation control (diaphC) on Sniff Nasal-Inspiratory Pressure (SNIP) and Maximum Relaxation Rate of inspiratory muscles (MRR) in healthy subjects. METHOD: Twenty subjects (9 male; age: 23 (SD=2.9) years; BMI: 23.8 (SD=3) kg/m2; FEV1/FVC: 0.9 (SD=0.1)] performed 5 sniff maneuvers in two different moments: with or without instruction on diaphC. Before the first maneuver, a brief explanation was given to the subjects on how to perform the sniff test. For sniff test with diaphC, subjects were instructed to perform intense diaphragm activation. The best SNIP and MRR values were used for analysis. MRR was calculated as the ratio of first derivative of pressure over time (dP/dtmax) and were normalized by dividing it by peak pressure (SNIP) from the same maneuver. RESULTS: SNIP values were significantly different in maneuvers with and without diaphC [without diaphC: -100 (SD=27.1) cmH2O/ with diaphC: -72.8 (SD=22.3) cmH2O; p<0.0001], normalized MRR values were not statistically different [without diaphC: -9.7 (SD=2.6); with diaphC: -8.9 (SD=1.5); p=0.19]. Without diaphC, 40% of the sample did not reach the appropriate sniff criteria found in the literature. CONCLUSION: Diaphragmatic control performed during SNIP test influences obtained inspiratory pressure, being lower when diaphC is performed. However, there was no influence on normalized MRR.

Evaluation of the effect of learning on the full extent of inspiratory and expiratory pressure in healthy adults / Avaliação do efeito de aprendizado na mensuração das pressões inspiratória e expiratória máximas em adultos saudáveis

BACKGROUND: Measurements of maximal inspiratory and expiratory pressure are used to assess the pressure developed by the respiratory muscles and the passive elastic recoil of the pulmonary system. Such measurements are also used as criteria for weaning from mechanical ventilation, to determine the functional consequences of several systemic diseases and the development of lung diseases and neuromuscular disorders. The test in na outpatient setting is easy to perform, well tolerated and has predictive value OBJECTIVE: To verify the presence of a learning effect in measurements of maximal inspiratory and expiratory pressures. METHODS: We performed 15 sequential measurements of Maximal Inspiratory Pressure and 15 of Maximal Expiratory Pressure in 71 individuals. Results for both series were compared throughout each series. RESULTS: The comparison between the first and the other measurements showed no statistically significant differences. (p > 0.05). CONCLUSIONS: There was no learning effect with 15 repeated measurements of Maximal Inspiratory or Expiratory Pressure in healthy adults.

INTRODUÇÃO: Medidas de pressão inspiratória máxima e pressão expiratória máxima são usados para avaliar a força desenvolvida pelos músculos respiratórios. Tais medidas são também utilizadas como critérios para o desmame da ventilação mecânica, para determinar as consequências funcionais de várias doenças sistêmicas e do desenvolvimento de doenças pulmonares e neuromusculares. OBJETIVO: Verificar a presença do efeito de aprendizado nas mensurações de pressão inspiratória e expiratória máximas. MÉTODO: Foram realizadas 15 medições sequenciais de pressão inspiratória máxima e 15 de pressão expiratória máxima em 71 indivíduos. Os resultados para ambas as séries foram comparados ao longo de cada série RESULTADOS: As comparações entre a primeira e as demais medidas não apresentaram diferenças estatisticamente significativas (p > 0,05). CONCLUSÃO: Não houve efeito aprendizado em 15 medidas repetidas de pressão inspiratória máxima ou pressão expiratória máxima em adultos saudáveis.

Pressão inspiratória máxima e sua relação com sintomas e fatoresassociados a doença de refluxo gastroesofágico

A doença do refluxo gastroesofágico é o retorno do conteúdo gástrico através do esfíncter esofágico inferior independentemente da sua etiologia, manifestando-se por sintomas (típicos ou atípicos) ou dano tecidual. O diafragma é o principal músculo respiratório e a sua parte crural um dos componentes fundamentais da barreira antirefluxo. As contrações deste são relacionadas às mudanças na pressão da junção esofagogástrica que normalmente são relacionadas com a respiração. Estudos apontamevidências de déficit diafragmático na doença de refluxo gastroesofágico que pode ser melhorado com treinamento diafragmático. A pressão inspiratória máxima é um método simples de avaliar a força inspiratória determinada pelo diafragma. A partir deste contexto, surgiu a hipótese de que os sintomas da doença de refluxo gastro esofágico podem se associar à pressão inspiratória máxima...

The gastroesophageal reflux disease is the return of gastric contents through the lower esophageal sphincter regardless of etiology, manifesting itself by symptoms (typical or atypical) or tissue damage. The diaphragm is the main respiratory muscle and its crural part one of the fundamental components of the antireflux barrier. Contractions of this are related to changes in pressure of the gastroesophageal junction that are usually related to breathing. Studies show evidence of diaphragmatic weaknessin gastroesophageal reflux disease that can be improved with diaphragmatic training. The maximalinspiratory pressure is a simple method to evaluate the inspiratory force determined by diaphragm. From this context, the hypothesis that the symptoms of gastroesophageal reflux disease may be associated with the maximal inspiratory pressure...

Reference Range of Respiratory Muscle Strength and Its Clinical Application in Amyotrophic Lateral Sclerosis: A Single-Center Study

BACKGROUND AND PURPOSE: Evaluating respiratory function is important in neuromuscular diseases. This study explored the reference ranges of the maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and sniff nasal inspiratory pressure (SNIP) in healthy adults, and applied them to amyotrophic lateral sclerosis (ALS) patients. METHODS: MIP, MEP, and SNIP were measured in 67 healthy volunteers aged from 21 to 82 years. Reference ranges were evaluated by multivariate regression analysis using the generalized additive modeling of location, scale, and shape method. Thirty-six ALS patients were reviewed retrospectively, and abnormal values of MIP, MEP, and SNIP were determined according to the reference ranges. RESULTS: MIP, MEP, and SNIP were abnormal in 57.1%, 51.4%, and 25.7% of the ALS patients, respectively. MIP and SNIP were significantly correlated with the degree of restrictive pattern and respiratory symptoms. The ALS Functional Rating Scale-Revised score was correlated with SNIP. CONCLUSIONS: This study has provided the reference range of respiratory muscle strength in healthy adults. This range is suitable for evaluating respiratory function in ALS patients.

Sniff Nasal Inspiratory Pressure in 299 Healthy Boys / 中国康复理论与实践

@#Objective To investigate the sniff nasal inspiratory pressure (SNIP) of Chinese boys. Methods 299 healthy boys aged 5-12 years were measured with SNIP. Their height, weight, and age were recorded. Results The SNIP averaged (76.9±22.6) cmH2O, and was (59.1±14.2) cmH2O, (76.9±19.5) cmH2O, (85.3±23.5) cmH2O and (83.0±22.6) cmH2O in the boys of 5-6 years old, 7-8 years old, 9-10 years old and 11-12 years old, respectively. It was significantly different among boys of 5-6 years old, 7-8 years old and 9-10 years old (P<0.05), but no significant difference between 9-10 years old and 11-12 years old (P=0.55). Regression analysis indicated significant relations of SNIP with age, height, weight and Body Mass Index (P<0.01). Conclusion The SNIP of Chinese healthy boys are different from abroad. It is necessary to establish the Chinese children SNIP reference range.

Sniff Nasal Inspiratory Pressure in 299 Healthy Boys / 中国康复理论与实践

Objective To investigate the sniff nasal inspiratory pressure (SNIP) of Chinese boys. Methods 299 healthy boys aged 5-12 years were measured with SNIP. Their height, weight, and age were recorded. Results The SNIP averaged (76.9 ± 22.6) cmH2O, and was (59.1±14.2) cmH2O, (76.9±19.5) cmH2O, (85.3±23.5) cmH2O and (83.0±22.6) cmH2O in the boys of 5-6 years old, 7-8 years old, 9-10 years old and 11-12 years old, respectively. It was significantly different among boys of 5-6 years old, 7-8 years old and 9-10 years old (P<0.05), but no significant difference between 9-10 years old and 11-12 years old (P=0.55). Regression analysis indicated significant relations of SNIP with age, height, weight and Body Mass Index (P<0.01). Conclusion The SNIP of Chinese healthy boys are different from abroad. It is necessary to establish the Chinese children SNIP reference range.

Pattern of Respiratory Deterioration in Sporadic Amyotrophic Lateral Sclerosis According to Onset Lesion by Using Respiratory Function Tests

Most amyotrophic lateral sclerosis (ALS) patients show focal onset of upper and lower motor neuron signs and spread of symptoms to other regions or the other side clinically. Progression patterns of sporadic ALS are unclear. The aim of this study was to evaluate the pattern of respiratory deterioration in sporadic ALS according to the onset site by using respiratory function tests. Study participants included 63 (42 cervical-onset [C-ALS] and 21 lumbosacral-onset [L-ALS]) ALS patients and 31 healthy controls. We compared respiratory function test parameters among the 3 groups. Age was 57.4+/-9.6 (mean+/-SD), 60.8+/-9, and 60.5+/-7 years, and there were 28, 15, and 20 male participants, in the C-ALS, L-ALS, and control groups, respectively. Disease duration did not differ between C-ALS and L-ALS patients. Sniff nasal inspiratory pressure (SNIP) was significantly low in C-ALS patients compared with controls. Maximal expiratory pressure (MEP) and forced vital capacity percent predicted (FVC% predicted) were significantly low in C-ALS and L-ALS patients compared with controls. Maximal inspiratory pressure to maximal expiratory pressure (MIP:MEP) ratio did not differ among the 3 groups. Eighteen C-ALS and 5 L-ALS patients were followed up. DeltaMIP, DeltaMEP, DeltaSNIP, DeltaPEF, and DeltaFVC% predicted were higher in C-ALS than L-ALS patients without statistical significance. Fourteen C-ALS (77.8%) and 3 L-ALS (60%) patients showed a constant MIP:MEP ratio above or below 1 from the first to the last evaluation. Our results suggest that vulnerability of motor neurons in sporadic ALS might follow a topographic gradient.