Ultrasound assessment of diaphragm thickness in athletes / Evaluación por ultrasonido del grosor del diafragma en atletas

SUMMARY: The main purpose of this study was to examine the correlation between the aerobic and anaerobic performance of diaphragm thickness in athletes. That study was conducted with 15 team athletes (TA) (age 21.80 ± 2.40 years), 15 individual athletes (IA) (age 18.93 ± 2.31 years) and the control group (CON) 10 people living sedentary lifestyles (age 23.60 ± 2.91 years). In this study, diaphragm muscle thickness (B-mode ultrasonography), respiratory function (spirometry and maximum inspiratory (MIP) and expiratory pressures (MEP), aerobic capacity yo-yo intermittent endurance Test 1 (YYIET-1), and anaerobic power by Monark 834 E were assessed. The diaphragm thickness was determined from the intercostalspace between the 8th and 9th ribs at the expiration time by ultrasound and from the intercostal space between the 10th and 11th ribs at inspiration and then, the thickness of the diaphragm was measured from the diaphragm is seen best. There was a positive correlation between DiTins (r= 0.477) and DiTins-ex (r= 0.473) parameters of TA. In IA, there was a significant correlation between DiTins and DiTins-ex parameters and Peak Power (r= 0.495 and 0.435, respectively) and average power (r= 0.483 and 0.446, respectively). No significant correlation in all parameters of the CON group (p<0.05). As a result, it was determined that athletes with high diaphragm thickness had higher anaerobic performance, and athletes with thinner diaphragm thickness had better VO2Max capacity. The diaphragm thickness of the athletes in individual branches was thicker than the team athletes, and their anaerobic performance was also higher.

RESUMEN: El objetivo principal de este estudio fue examinar la correlación entre el rendimiento aeróbico y anaeróbico del grosor del diaframa en atletas. Dicho estudio se realizó con 15 deportistas de equipo (TA) (edad 21,80 ± 2,40 años), 15 deportistas individuales (IA) (edad 18,93 ± 2,31 años) y el grupo control (CON) 10 personas con sedentarismo (edad 23,60 ± 2,91 años). Se midió, el grosor del diaframa (ultrasonografía en modo B), la función respiratoria (espirometría y presiones máximas inspiratorias (MIP) y espiratorias (MEP), prueba de resistencia intermitente yo- yo de capacidad aeróbica 1 (YYIET-1) y resistencia anaeróbica potencia por Monark 834 E. El grosor del diafragma se determinó a partir del espacio intercostal entre las costillas 8 y 9 en el momento de la espiración por ultrasonido y del espacio intercostal entre las costillas 10 y 11 en la inspiración. Hubo una correlación positiva entre los parámetros DiT ins (r= 0,477) y DiTins-ex (r= 0,473) de TA. En IA, hubo una correlación significativa entre los parámetros DiTins y DiTins-ex y el pico Potencia (r= 0,495 y 0,435, respectivamente) y potencia media (r= 0,483 y 0,446, respectivamente). No hubo correlación significativa en todos los parámetros del grupo CON (p<0,05). Como resultado, se determinó que los atletas con mayor espesor del diaframa tenían un mayor rendimiento anaeróbico, y los atletas con menor espesor del diaframa tenían una mejor capacidad de VO2Max. El grosor del diafragma de los atletas en ramas individuales fue mayor que el de los atletas de equipo, y su rendimiento anaeróbico también fue mayor.

Fisiología respiratoria: fisiología de los músculos de la respiración / Physiology of the respiratory muscles

La respiración es un proceso continuo donde los músculos respiratorios tienen un rol central e imprescindible para la vida. Su óptimo funcionamiento involucra diversas estructuras que deben funcionar de forma armónica y coordinada, para que el gasto energético asociado a sus demandas permita aumentos considerables de carga sin afectar mayormente la función esencial de intercambio gaseoso. Comprender la fisiología muscular, desde la base anatómica hasta su comportamiento en el ejercicio y la enfermedad, es fundamental para detectar con anticipación las diversas disfunciones que se producen cuando este equilibrio se descompensa. El objetivo de esta revisión es entregar las bases fisiológicas del comportamiento de la musculatura respiratoria que permitan comprender y aplicar las mejores estrategias de evaluación y tratamiento, cuando la función normal se ve alterada, ya sea por enfermedad, desuso o altas cargas asociadas al ejercicio físico.

Breathing is a continuous process where the respiratory muscles have a central and essential role for life. Its optimal operation involves various structures that must work in a harmonious and coordinated way, so that the energy expenditure associated with their demands allows considerable increases in load without significantly affecting the essential function of gas exchange. Understanding muscle physiology, from the anatomical basis to its behavior in exercise and disease, is essential to anticipate the various dysfunctions that can occur when this balance is decompensated. The objective of this review is to provide physiological bases for the behavior of the respiratory muscles that allow understanding and applying the best evaluation and treatment strategies, when its correct functioning is altered, either due to illness, disuse or high loads associated with physical exercise.

El diafragma, el hiato y la unión gastroesofágica / The diaphragm, the hiatus and the gastroesophageal junction

RESUMEN La unión del tubo esofágico con el estómago en lo que denominamos el cardias, su tránsito y relacio nes con el hiato diafragmático, las estructuras fibromembranosas que la fijan y envuelven, la existencia de un esfínter gastroesofágico anatómico y su real morfología, así como la interacción de todos estos elementos, han sido materia de controversia por décadas y aún hoy. Este artículo actualiza la descrip ción de tales estructuras.

ABSTRACT The point where the esophagus connects to the stomach, known as the cardia, its transition and re lationship with the diaphragmatic hiatus, its fibromembranous attachments, the existence of an ana tomic gastroesophageal sphincter and its real morphology, and the interaction between all these ele ments, have been subject of debate for decades that still persist. The aim of this article is to describe the updated information of such structures.

Mobilidade diafragmática em saudáveis: escolher a média dos valores ou o maior valor mensurado? / Diaphragmatic mobility on healthy individuals: choosing between mean or the highest measured values

A mobilidade diafragmática é essencial para a ventilação pulmonar. Pela ultrassonografia sua mensuração é direta, porém o processamento das medidas encontra-se em divergência na literatura. Indica-se pelo valor médio das três incursões respiratórias máximas ou o maior valor dentre elas restringindo à variações de 10%. Dessa forma, não existe um consenso em relação ao processamento da medida de mobilidade diafragmática máxima. Objetivo: Comparar dois diferentes processamentos das medidas pela ultrassonografia para o maior valor de mobilidade diafragmática. Materiais e métodos: Estudo observacional transversal. Avaliou-se a mobilidade diafragmática pela ultrassonografia, com um transdutor convexo (3 MHz) posicionado anteriormente na região subcostal e leve inclinação cranial, em decúbito dorsal. Visualizou-se o hemidiafragma direito pelo ponto médio entre a linha médio clavicular e axilar anterior. Para visualizar a janela do diafragma e mensurar sua mobilidade foi utilizado o modo B, seguido do modo M. Os participantes realizaram inspirações máximas e os maiores valores com diferença máxima de 10% entre eles mensurados e registrados. Para análise, o maior valor e o valor médio obtido das três medidas foram considerados. Para normalidade dos dados foi realizado o teste de Shapiro Wilk. Para diferenças entre os registros, o teste de t student. Resultados: 30 indivíduos (30,33 ± 9,7 anos), 16 mulheres e 14 homens. A medida da mobilidade diafragmática pelo maior valor em comparação ao valor médio apresentou diferença estatisticamente significante (8,11 ± 1,43 cm versus 7,79 ± 1,43 cm; p<0,001). Conclusão: O valor máximo da mobilidade diafragmática foi obtido por meio da análise do maior valor. Ao escolher a média, a mobilidade diafragmática pode ser subestimada. 

Diaphragmatic mobility is essential to pulmonary ventilation. It can be directly measured by using ultrasonography, but the processing of the measurements can be found described differently in the literature. It can be measured as the average of at least three different cycles or from the greatest value among them resticting it to a 10% variation. Thus, there is no consensus about the processing of the maximum measurement of diaphragmatic mobility. Objective: Comparisson of two differents ultrasound measurement processings aiming at the diaphragmatic mobility maximum value. Methodology: Cross-sectional observational study. The diaphragmatic mobility was assessed by ultrasonography with convex transducer (3MHz) placed on the subcostal region between the midclavicular and anterior axillary. In order to explore the right diaphragmatic window and mobility, the B mode was used, followed by the M mode. The participants made maximum inspiration, and the highest value with a maximum difference of 10% was recorded. For statistical analysis, the mean and the highest value of three measurements were considered. The data distribution was analyzed with a Shapiro Wilk test and differences among records by the t student test. Results: 30 participants (30.33 ± 9.7 years) - 16 women and 14 men. The measurement of the diaphragmatic mobility obtained by the highest value compared against the mean value presented a statistically significant difference (8.11 ± 1.43 cm vs 7.79 ± 1.43 cm; p<0.001). Conclusions: The maximum value of diaphragmatic mobility was obtained by the analysis of the highest value. By choosing to use the mean value, diaphragmatic mobility may be underestimated.

Lipoabdominoplasty: repercussions for diaphragmatic mobility and lung function in healthy women / Lipoabdominoplastia: repercussão na mobilidade diafragmática e função pulmonar em mulheres saudáveis

ABSTRACT Objective: To evaluate the impact of lipoabdominoplasty on diaphragmatic mobility (DM) and lung function in healthy women. Methods: This was a prospective cohort study using high-resolution ultrasound and forced spirometry to assess DM and lung function, respectively, prior to lipoabdominoplasty, as well as on postoperative day (POD) 10 and POD 30. DM was measured under two conditions: during tidal volume breathing and during a VC maneuver. Results: The sample consisted of 20 women, with a mean age of 39.85 ± 7.52 years and a mean body mass index of 26.21 ± 2.0 kg/m2. Comparing the preoperative and postoperative periods, we found that DM and lung function values were significantly lower after lipoabdominoplasty, the mean DM on POD 10 being 17% and 15% lower during tidal volume breathing and during the VC maneuver, respectively, in comparison with the preoperative mean (p = 0.009 and p < 0.001, respectively). In addition, FEV1, FVC, and PEF were significantly lower on POD 10 than in the preoperative period (p = 0.046, p = 0.002, and p < 0.001, respectively), returning to preoperative values by POD 30. Conclusions: Lipoabdominoplasty appears to have negative short-term repercussions for DM and lung function in healthy women. However, lung function and DM are both apparently restored to preoperative conditions by POD 30. (ClinicalTrials.gov identifier: NCT02762526 [http://www.clinicaltrials.gov/])

RESUMO Objetivo: Avaliar o impacto da lipoabdominoplastia na mobilidade diafragmática (MD) e na função pulmonar de mulheres saudáveis. Métodos: Estudo prospectivo de coorte com ultrassonografia de alta resolução e espirometria forçada para a avaliação da MD e da função pulmonar, respectivamente, antes da lipoabdominoplastia, no 10º dia do pós-operatório e no 30º dia do pós-operatório. A MD foi medida durante a respiração em volume corrente e durante uma manobra de CV. Resultados: A amostra foi composta por 20 mulheres, com média de idade de 39,85 ± 7,52 anos e média de índice de massa corporal de 26,21 ± 2,0 kg/m2. Ao compararmos os períodos pré e pós-operatório, observamos que a MD e a função pulmonar foram significativamente menores após a lipoabdominoplastia; a média de MD no 10º dia do pós-operatório foi 17% menor durante a respiração em volume corrente e 15% menor durante a manobra de CV do que a média pré-operatória (p = 0,009 e p < 0,001, respectivamente). Além disso, o VEF1, a CVF e o PFE foram significativamente menores no 10º dia do pós-operatório que no pré-operatório (p = 0,046, p = 0,002 e p < 0,001, respectivamente), retornando aos valores pré-operatórios até o 30º dia do pós-operatório. Conclusões: A lipoabdominoplastia parece ter repercussões negativas em curto prazo na MD e função pulmonar de mulheres saudáveis. No entanto, tanto a função pulmonar como a MD aparentemente retornam ao estado pré-operatório até o 30º dia do pós-operatório. (ClinicalTrials.gov identifier: NCT02762526 [http://www.clinicaltrials.gov/])

Validity and reliability of assessing diaphragmatic mobility by area on X-rays of healthy subjects / Validade e confiabilidade da avaliação da mobilidade diafragmática pelo método da área radiográfica em sujeitos saudáveis

ABSTRACT Objective: To investigate the concurrent validity, as well as the intra- and inter-rater reliability, of assessing diaphragmatic mobility by area (DMarea) on chest X-rays of healthy adults. Methods: We evaluated anthropometric parameters, pulmonary function, and diaphragmatic mobility in 43 participants. Two observers (rater A and rater B) determined diaphragmatic mobility at two time points. We used Pearson's correlation coefficient to evaluate the correlation between DMarea and the assessment of diaphragmatic mobility by distance (DMdist). To evaluate intra- and inter-rater reliability, we used the intraclass correlation coefficient (ICC [2,1]), 95% CI, and Bland-Altman analysis. Results: A significant correlation was found between the DMarea and DMdist methods (r = 0.743; p < 0.0001). For DMarea, the intra-rater reliability was found to be quite high for the right hemidiaphragm (RHD)-ICC (2,1) = 0.92 (95% CI: 0.86-0.95) for rater A and ICC (2,1) = 0.90 (95% CI: 0.84-0.94) for rater B-and the left hemidiaphragm (LHD)-ICC (2,1) = 0.96 (95% CI: 0.93-0.97) for rater A and ICC (2,1) = 0.91 (95% CI: 0.81-0.95) for rater B-(p < 0.0001 for all). Also for DMarea, the inter-rater reliability was found to be quite high for the first and second evaluations of the RHD-ICC (2,1) = 0.99 (95% CI: 0.98-0.99) and ICC (2,1) = 0.95 (95% CI: 0.86-0.97), respectively-and the LHD-ICC (2,1) = 0.99 (95% CI: 0.98-0.99) and ICC (2,1) = 0.94 (95% CI: 0.87-0.97)-(p < 0.0001 for both). The Bland-Altman analysis showed good agreement between the mobility of the RHD and that of the LHD. Conclusions: The DMarea method proved to be a valid, reliable measure of diaphragmatic mobility.

RESUMO Objetivo: Avaliar a validade concorrente, assim como a confiabilidade intra e interobservador, da avaliação da mobilidade diafragmática pelo método da área radiográfica (MDárea) em adultos saudáveis. Métodos: Foram avaliados os parâmetros antropométricos, a função pulmonar e a mobilidade diafragmática de 43 participantes. A mobilidade diafragmática foi determinada por dois observadores (A e B) em dois momentos distintos. O coeficiente de correlação de Pearson foi utilizado para avaliar a correlação entre o método da MDárea e o método por distância (MDdist). Para avaliar a confiabilidade intra e interobservador, foi utilizado o coeficiente de correlação intraclasse (CCI [2,1]), IC95% e a disposição gráfica de Bland & Altman. Resultados: Houve uma correlação significativa entre MDárea e MDdist (r = 0,743; p < 0,0001). Para MDárea, a confiabilidade intraobservador foi alta para a avaliação radiográfica do hemidiafragma direito (HDD) - CCI (2,1) = 0,92 (IC95%: 0,86-0,95) para o observador A e CCI (2,1) = 0,90 (IC95%: 0,84-0,94) para o observador B - e do hemidiafragma esquerdo (HDE) - CCI (2,1) = 0,96 (IC95%: 0,93-0,97) para o observador A e CCI (2,1) = 0,91 (IC95%: 0,81-0,95 para o observador B (p < 0,0001 para todos). Também para MDárea, a confiabilidade interobservador foi alta para a primeira e segunda avaliações do HDD - CCI (2,1) = 0,99 (IC95%: 0,98-0,99) e CCI (2,1) = 0,95 (IC95%: 0,86-0,97), respectivamente - e HDE - CCI (2,1) = 0,94 (IC95%: 0,87-0,97) e CCI (2,1) = 0,94 (IC95%: 0,87-0,97), respectivamente - (p < 0,0001 para ambos). A disposição gráfica de Bland & Altman mostrou uma boa concordância entre as medidas de mobilidade de HDD e HDE. Conclusões: O método de MDárea demonstrou ser válido e reprodutível para medir a mobilidade diafragmática.

Avaliação dos índices de desmame com base na atividade do diafragma em pacientes submetidos à ventilação mecânica após cirurgia cardiovascular. Um estudo piloto / Assessment of weaning indexes based on diaphragm activity in mechanically ventilated subjects after cardiovascular surgery. A pilot study

RESUMO Objetivo: Avaliar a viabilidade do uso de índices derivados do sinal de eletromiografia de superfície para predizer desfechos do processo de desmame em pacientes mecanicamente ventilados após cirurgia cardíaca. Métodos: Foram incluídos dez pacientes em pós-operatório de cirurgia cardiovascular que não cumpriram os critérios para extubação precoce. Os sinais da eletromiografia de superfície foram registrados, assim como as variáveis ventilatórias durante o processo de desmame, sendo o momento do procedimento determinado pela equipe médica, segundo sua experiência. Avaliaram-se diversos índices da atividade dos músculos respiratórios obtidos a partir da eletromiografia de superfície com uso de técnicas de processamento lineares e não lineares. Compararam-se dois grupos: pacientes com e sem sucesso no desmame. Resultados: Os índices obtidos permitiram estimar a atividade diafragmática de cada paciente, demonstrando uma correlação entre atividade elevada e falha do teste de desmame. Conclusão: A eletromiografia de superfície está se tornando um procedimento promissor para avaliar as condições de pacientes ventilados mecanicamente, mesmo em condições complexas, como as que envolvem aqueles após cirurgia cardiovascular.

ABSTRACT Objective: The aim of this pilot study was to evaluate the feasibility of surface electromyographic signal derived indexes for the prediction of weaning outcomes among mechanically ventilated subjects after cardiac surgery. Methods: A sample of 10 postsurgical adult subjects who received cardiovascular surgery that did not meet the criteria for early extubation were included. Surface electromyographic signals from diaphragm and ventilatory variables were recorded during the weaning process, with the moment determined by the medical staff according to their expertise. Several indexes of respiratory muscle expenditure from surface electromyography using linear and non-linear processing techniques were evaluated. Two groups were compared: successfully and unsuccessfully weaned patients. Results: The obtained indexes allow estimation of the diaphragm activity of each subject, showing a correlation between high expenditure and weaning test failure. Conclusion: Surface electromyography is becoming a promising procedure for assessing the state of mechanically ventilated patients, even in complex situations such as those that involve a patient after cardiovascular surgery.

Respiratory muscle training improves diaphragm citrate synthase activity and hemodynamic function in rats with heart failure

Abstract INTRODUCTION: Enhanced respiratory muscle strength in patients with heart failure positively alters the clinical trajectory of heart failure. In an experimental model, respiratory muscle training in rats with heart failure has been shown to improve cardiopulmonary function through mechanisms yet to be entirely elucidated. OBJECTIVE: The present report aimed to evaluate the respiratory muscle training effects in diaphragm citrate synthase activity and hemodynamic function in rats with heart failure. METHODS: Wistar rats were divided into four experimental groups: sedentary sham (Sed-Sham, n=8), trained sham (RMT-Sham, n=8), sedentary heart failure (Sed-HF, n=7) and trained heart failure (RMT-HF, n=7). The animals were submitted to a RMT protocol performed 30 minutes a day, 5 days/week, for 6 weeks. RESULTS: In rats with heart failure, respiratory muscle training decreased pulmonary congestion and right ventricular hypertrophy. Deleterious alterations in left ventricular pressures, as well as left ventricular contractility and relaxation, were assuaged by respiratory muscle training in heart failure rats. Citrate synthase activity, which was significantly reduced in heart failure rats, was preserved by respiratory muscle training. Additionally, a negative correlation was found between citrate synthase and left ventricular end diastolic pressure and positive correlation was found between citrate synthase and left ventricular systolic pressure. CONCLUSION: Respiratory muscle training produces beneficial adaptations in the diaphragmatic musculature, which is linked to improvements in left ventricular hemodynamics and blood pressure in heart failure rats. The RMT-induced improvements in cardiac architecture and the oxidative capacity of the diaphragm may improve the clinical trajectory of patients with heart failure.

Diaphragmatic mobility: relationship with lung function, respiratory muscle strength, dyspnea, and physical activity in daily life in patients with COPD / Relação da mobilidade diafragmática com função pulmonar, força muscular respiratória, dispneia e atividade física de vida diária em pacientes com DPOC

ABSTRACT Objective: To evaluate diaphragmatic mobility in relation to lung function, respiratory muscle strength, dyspnea, and physical activity in daily life (PADL) in patients with COPD. Methods: We included 25 patients with COPD, classified according to the Global Initiative for Chronic Obstructive Lung Disease criteria, and 25 healthy individuals. For all of the participants, the following were evaluated: anthropometric variables, spirometric parameters, respiratory muscle strength, diaphragmatic mobility (by X-ray), PADL, and the perception of dyspnea. Results: In the COPD group, diaphragmatic mobility was found to correlate with lung function variables, inspiratory muscle strength, and the perception of dyspnea, whereas it did not correlate with expiratory muscle strength or PADL. Conclusions: In patients with COPD, diaphragmatic mobility seems to be associated with airway obstruction and lung hyperinflation, as well as with ventilatory capacity and the perception of dyspnea, although not with PADL.

RESUMO Objetivo: Avaliar a relação da mobilidade diafragmática com a função pulmonar, força muscular respiratória, dispneia e atividade física de vida diária (AFVD) em pacientes com DPOC. Métodos: Foram avaliados 25 pacientes com diagnóstico de DPOC, classificados de acordo com critérios da Global Initiative for Chronic Obstructive Lung Disease, e 25 indivíduos saudáveis. Todos foram submetidos às seguintes avaliações: mensuração antropométrica, espirometria, força muscular respiratória, mobilidade diafragmática (por radiografia), AFVD e percepção de dispneia. Resultados: No grupo DPOC, houve correlações da mobilidade diafragmática com variáveis de função pulmonar, força muscular inspiratória e percepção de dispneia. Não houve correlações da mobilidade diafragmática com força muscular expiratória e AFVD. Conclusões: A mobilidade diafragmática parece estar associada tanto com a obstrução das vias aéreas quanto com a hiperinsuflação pulmonar em pacientes com DPOC, assim como com a capacidade ventilatória e percepção de dispneia, mas não com AFVD.

Effects of diaphragm stretching on posterior chain muscle kinematics and rib cage and abdominal excursion: a randomized controlled trial

ABSTRACT Background Few studies have explored the effects of stretching techniques on diaphragm and spine kinematics. Objective To determine whether the application of diaphragm stretching resulted in changes in posterior chain muscle kinematics and ribcage and abdominal excursion in healthy subjects. Method Eighty healthy adults were included in this randomized clinical trial. Participants were randomized into two groups: the experimental group, which received a diaphragmatic stretching technique, or the placebo group, which received a sham-ultrasound procedure. The duration of the technique, the position of participants, and the therapist who applied the technique were the same for both treatments. Participant assessment (cervical range of movement, lumbar flexibility, flexibility of the posterior chain, and rib cage and abdominal excursion) was performed at baseline and immediately after the intervention by a blinded assessor. Results The mean between-group difference [95% CI] for the ribcage excursion after technique at xiphoid level was 2.48 [0.97 to 3.99], which shows significant differences in this outcome. The remaining between-group analysis showed significant differences in cervical extension, right and left flexion, flexibility of the posterior chain, and ribcage excursion at xiphoid level (p<0.05) in favor of the experimental group. Conclusion Diaphragm stretching generates a significant improvement in cervical extension, right and left cervical flexion, flexibility of the posterior chain, and ribcage excursion at xiphoid level compared to a placebo technique in healthy adults.

Technique for implanting intramuscular electrodes in the diaphragm by videolaparoscopy in pigs

PURPOSE: To describe a novel approach for implanting intramuscular electrodes in the diaphragm through videolaparoscopy. METHODS: We used twelve pigs for this videolaparoscopic technique, which permits at the same time to explore the diaphragm, to locate its motor points and to fix the electrodes in the diaphragm bilaterally. In this technique we used three trocars: one portal for a 10-mm 0° viewing angle laparoscope, one portal for the manipulation of structures and another for electrode implantation. RESULTS: All animals survived the procedure without pneumothorax/capnothorax or other complication. Implanted electrodes provided an appropriate interface between the muscle and the electrical current generator, and electroventilation was satisfactorily generated in all animals. CONCLUSION: This videolaparoscopic technique with three trocars enables the exploration and identification of motor points and an efficient fixation of one or two electrodes in each hemidiaphragm.

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.

Disfunción diafragmática inducida por ventilación mecánica / Ventilator-induced diaphragmatic dysfunction

The ventilator-induced diaphragmatic dysfunction is a group of disorders caused by the inactivity of the diaphragm muscle during controlled mechanical ventilation. From a structural point of view, the diaphragm subjected to mechanical ventilation undergoes an atrophy process, in which decreased synthesis and increased muscle protein degradation are observed. Recent research has identified different molecular signaling pathways that link both processes in the diaphragm, describing compelling evidence that shows that oxidative stress contributes to this phenomenon. Also, functional changes characterized by a reduction in stress and fatigue resistance, associated with an increase in the maximum shortening velocity are observed. The purpose of the present review is to analyze the impact of mechanical ventilation on the structure and function of the diaphragm muscle. Clinical implications and potential preventive steps are discussed. Since the duration of mechanical ventilation is the primary responsible for the absence of mechanical stimulation on the diaphragm, the use of ventilatory strategies for successful early weaning and early use of partial modalities should be the main pillars in the prevention of this condition.

La disfunción diafragmática inducida por ventilación mecánica consiste en un conjunto de alteraciones producidas por la inactividad del músculo diafragma durante la ventilación mecánica controlada. A nivel estructural, el diafragma sometido a ventilación mecánica experimenta un proceso de atrofia por desuso, en el que se observa una disminución de la síntesis y aumento en la degradación de proteínas musculares. Recientemente se han identificado diferentes rutas de señalización molecular que vinculan ambos procesos en el diafragma, existiendo evidencia fehaciente que el estrés oxidativo contribuye a este fenómeno. Concomitantemente, se han observado cambios funcionales caracterizados por una reducción de la fuerza y resistencia a la fatiga, asociado a un incremento en la velocidad máxima de acortamiento. El objetivo principal de esta revisión es analizar el impacto de la ventilación mecánica sobre la estructura y función del músculo diafragma. Además se discuten implicancias clínicas y potenciales intervenciones preventivas para esta emergente entidad. Dado que el tiempo de permanencia en ventilación mecánica controlada es el principal factor responsable de la ausencia de estímulo mecánico sobre el diafragma, el empleo de estrategias de destete ventilatorio precoz y el uso temprano de modalidades parciales, debieran constituir los pilares de su prevención.

A retrospective study of diaphragmatic motion, pulmonary function, and quality-of-life following video-assisted thoracoscopic lobectomy in patients with nonsmall cell lung cancer.

BACKGROUND: Diaphragmatic dysfunction and its negative physiologic disadvantages are less commonly reported in patients with lung cancer video‑assisted thoracoscopic lobectomy. The aim of this study was to investigate the outcomes of this complication on pulmonary function and quality‑of‑life in patients following video‑assisted thoracoscopic lobectomy. OBJECTIVES: The aim of this study was to investigate potential benefits on pulmonary function and quality‑of‑life with normal diaphragmatic motion. MATERIALS AND METHODS: A retrospective study was conducted in 64 patients with nonsmall cell lung cancer after video‑assisted thoracoscopic lobectomy. The population were divided into groups 1 (with diaphragmatic paralysis, n = 32) and group 2 (without diaphragmatic paralysis, n = 32) according diaphragmatic motion after postoperatively 6 months. And then, we investigated the difference between the two groups on pulmonary function and quality‑of‑life. RESULTS: (1) At 6 months after resection, the patients in group 1 had lost 25% of their preoperative forced expiratory volume in the 1 s (FEV1) (P < 0.001), and the patients in group 2 had lost 15% of their preoperative FEV1 (P < 0.001). And the other spirometric variables in group 1 were significantly worse than that of group 2 (P < 0.001). (2) The most frequently reported postoperative symptoms were fatigue, coughing, dyspnea, and thoracotomy pain in two groups. Of all the symptom scales, only the dyspnea scale showed a significant difference which subject has a higher proportion and scale compared to control. CONCLUSIONS: The present study indicates that unilateral diaphragmatic paralysis following video‑assisted thoracoscopic lobectomy caused adverse effects on postoperative pulmonary function and quality‑of‑life.

Negative modulation of NO for diaphragmatic contractile reduction induced by sepsis and restraint position / 法医学杂志

In practice of forensic medicine, potential disease can be associated with fatal asphyxia in restraint position. Research has demonstrated that nitric oxide (NO) and nitric oxide synthase (NOS) are plentifully distributed in skeletal muscle, contributing to the regulation of contractile and relaxation. In the current study, respiratory functions, indices of diaphragmatic biomechanical functions ex vivo, as well as NO levels in serum, the expressions of diaphragmatic inducible NOS (iNOS) mRNA, and the effects of L-NNA on contractility of the diaphragm were observed in sepsis induced by cecal ligation and puncture (CLP) under the condition of restraint position. The results showed that in the CLP12-18h rats, respiratory dysfunctions; indices of diaphragmatic biomechanical functions (Pt, +dT/dt(max), -dT/dt(max), CT, Po, force over the full range of the force-frequency relationship and fatigue resistance) declined progressively; the NO level in serum, and iNOS mRNA expression in the diaphragm increased progressively; force increased significantly at all stimulation frequencies after L-NNA pre-incubation. Restraint position 1 h in CLP12 h rats resulted in severe respiratory dysfunctions after relative stable respiratory functions, almost all the indices of diaphragmatic biomechanical functions declined further, whereas little change took place in NO level in serum and diaphragmatic iNOS mRNA expression; and the effects of L-NNA were lack of statistical significance compared with those of CLP12 h, but differed from CLP18 h group. These results suggest that restraint position and sepsis act together in a synergistic manner to aggravate the great reduction of diaphragmatic contractility via, at least in part, the negative modulation of NO, which may contribute to the pathogenesis of positional asphyxia.

High reliability of measure of diaphragmatic mobility by radiographic method in healthy individuals / High reliability of measure of diaphragmatic mobility by radiographic method in healthy individuals

BACKGROUND: Diaphragmatic evaluation is crucial in clinical practice, and no studies have reported the intra- and interobserver reproducibilities of the radiographic method to evaluate diaphragmatic mobility. OBJECTIVE: To analyze the reliability of radiographic measurement as a method for assessing the mobility of the left and right hemidiaphragms. METHOD: Forty-two patients, who were waiting for cholecystectomy surgery, were evaluated relative to the following parameters: physical examination, pulmonary function and radiographic evaluation. The measure of mobility of each hemidiaphragm was randomly determined by two physical therapists at two different times. The intra- and interobserver reproducibilities of the measurements were determined by the intraclass correlation coefficient (ICC[2,1]) and the 95% confidence interval (CI). The Bland-Altman plot was also used. The level of significance was 5%. RESULTS: In the analysis of intra-observer reproducibility in radiographic evaluations of the left and right hemidiaphragms, ICC[2,1] indicated a "very high correlation" for both observer A (ICC[2,1] = 0.99, p <0.001 and ICC[2,1] = 0.97, p <0.001, respectively) and observer B (ICC[2,1] = 0.99, p <0.001 and ICC[2,1] = 0.99 p <0.001, respectively). In the analysis of interobserver reproducibility, the ICC[2,1] indicated a "very high correlation" for the 1st and 2nd radiographic evaluations of the right hemidiaphragm (ICC[2,1] = 0.98 and ICC[2,1] = 0,99, respectively, p <0.001) and left hemidiaphragm (ICC[2,1] = 0.98 and ICC[2,1] = 0.99, respectively, p <0.001). CONCLUSION: The intra and interobserver tests of the radiographic measure of mobility of the left and right hemidiaphragms showed high reliability. .

CONTEXTUALIZAÇÃO: A avaliação diafragmática é fundamental na prática clínica, e não existem estudos que verificam a reprodutibilidade intra e interobservadores do método radiográfico com objetivo de avaliar a mobilidade diafragmática. OBJETIVO: Analisar a confiabilidade da medida radiográfica como método de avaliação da mobilidade dos hemidiafragmas direito e esquerdo. MÉTODO: Foram avaliados 42 pacientes no pré-operatório de colecistectomia. Os parâmetros utilizados foram: exame físico, prova de função pulmonar e avaliação radiográfica. A medida da mobilidade de cada hemidiafragma foi determinada, aleatoriamente, por dois fisioterapeutas em dois momentos. A reprodutibilidade intra e interobservadores das medidas foi determinada pelo Coeficiente de Correlação Intraclasse (ICC[2,1]) e pelo intervalo de confiança (IC) de 95%. A disposição gráfica de Bland & Altman também foi utilizada. O nível de significância adotado foi de 5%. RESULTADOS: Na análise da reprodutibilidade intraobservador, o ICC[2,1] indicou "correlação muito alta" para o observador A na avaliação radiográfica dos hemidiafragmas direito e esquerdo (ICC[2,1] = 0,99, p<0,001 e ICC[2,1] = 0,97 p<0,001, respectivamente) e também para o observador B (ICC[2,1] = 0,99, p<0,001 e ICC[2,1] = 0,99 p<0,001, respectivamente). Na análise da reprodutibilidade interobservadores, o ICC[2,1] indicou "correlação muito alta" para a 1ª e 2ª avaliações radiográficas dos hemidiafragmas direito (ICC[2,1] = 0,98 e ICC[2,1] = 0,99, respectivamente, p<0,001) e esquerdo (ICC[2,1] = 0,98 e ICC[2,1] = 0,99, respectivamente, p<0,001). CONCLUSÃO: ...

Evaluación por imágenes del diafragma en el niño / Image evaluation of diaphragm in children

The anatomy, embriology andfunctions of the neonate 's diaphragm, as well as its anatomical and functional oddities were reviewed. And, in a deeper way, imaging studies were also reviewed; these have an important role in functional and anatomic evaluation of the diaphragm, each one with its own advantages and limitations. Chest X-rays allow an anatomic two dimensional evaluation of the diaphragm and constitutes the first approach in the study of diaphragm pathology in children; hence, the normal anatomy and the most common pathological signs are reviewed. Digestive tube studies using contrast media still are the best choice for diagnosis of hiatal hernia and of herniation through the foramen of Morgagni, where the colon is ascended. Ultrasound use is highlighted for the evaluation of diaphragmatic motility, as well as some of its advantages over fluoroscopy, which is and has been the method of choice in the diagnosis of diaphragmatic paralysis in children. Multiplanar images are the most complete method for the anatomic evaluation of the diaphragm, since they show its spatial orientation and allow the detailed evaluation of those pahologies where the anatomy is altered, such as diaphragmatic hernias, trauma and tumors.

Revisamos la embriología, anatomía y funciones del diafragma, sus particularidades anatómicas y funcionales en los neonatos y, en forma más profunda, los estudios por imágenes, que en la actualidad tienen un importante rol en su evaluación anatómica y funcional, cada uno de ellos con sus ventajas y limitaciones. La radiografía de tóraxpermite una evaluación anatómica en dos planos del diafragma y constituye la primera aproximación en el estudio de la patología del diafragma en los niños, por lo que se describe la anatomía normal y los signos de las patologías más frecuentes. Los estudios contrastados del tubo digestivo siguen siendo de elección para el estudio de las hernias hiatales y hernias de Morgagni en donde está ascendido el colon. Destacamos el uso del ultrasonido en la evaluación de la motilidad diafragmática, y algunas de sus ventajas sobre la fluoroscopia, que es y ha sido el método de elección en el diagnóstico de la parálisis diafragmática en los niños. Las imágenes multiplanares son un método más completo en la evaluación anatómica del diafragma, muestran mejor su orientación espacial y permiten la evaluación detallada de las patologías donde la anatomía está alterada, como hernias diafragmáticas congénitas, trauma y tumores.

Descrição morfológica do diafragma do sagui-de-tufo-branco (Callithrix jacchus) / Morphological description of diaphragm of white-tufted-ear-marmoset (Callithrix jacchus)

O músculo diafragma, encontrado apenas nos mamíferos, é o principal músculo no processo respiratório, servindo de fronteira entre as cavidades torácica e abdominal. Sua importância também ganha destaque em pesquisas realizadas no âmbito dos enxertos, empregando-se diversos tipos de membranas biológicas para o reparo de defeitos diafragmáticos, os quais podem gerar hérnias diafragmáticas. Apesar de muitos estudos já conduzidos para com os primatas não humanos, especialmente no que tange a espécie do novo mundo Callithrix jacchus (Sagui-de-tufo-branco), oriundo do nordeste brasileiro, as pesquisas envolvendo o uso do diafragma em tal espécie é inexistente. Deste modo objetivou-se caracterizar a morfologia e a biometria do diafragma na espécie Callithrix jacchus de ambos os sexos, analisando possíveis divergências estruturais entre machos e fêmeas. Para tal foram utilizados quatros animais, 2 machos e 2 fêmeas, adultos, que vieram a óbito por causas naturais, provenientes de um criadouro comercial. Após fixação em solução de formaldeído 10% os animais foram devidamente dissecados para fotodocumentação e em seguida o diafragma coletado para efetuação da biometria (comprimento e largura) com o uso de um paquímetro e para o processamento histológico por meio da coloração de hematoxilina-eosina e tricrômio de masson, da porção muscular. As mensurações feitas permitiram concluir que não houve diferenças signifcativas entre machos e femeas. A topografia e a presença de três aberturas (forame da veia cava caudal, hiato aórtico e esofágico) na extensão do diafragma corroboram com descrições na literatura classica para outros mamíferos. A presença de um centro tendíneo em "V" difere do encontrado para animais como o peixe-boi e porquinho-da-india, mas é similar ao encontrado para o gambá-de-orelhas-brancas e rato albino. No que diz respeito aos achados histológicos conclui-se que as fibras musculares estão dispostas de forma organizada, apresentam diâmetro grande e núcleos basais, tendo, portanto, características similares do músculo estriado esquelético tanto nos animais machos como nas fêmeas.

The diaphragm muscle found only in mammals is the main muscle in the respiratory process, serving as the border between the thoracic and abdominal cavities. Its significance also is highlighted in research conducted with grafts using various types of biological membranes for the repair of diaphragmatic defects which may cause diaphragmatic hernias. In spite of many studies already conducted in non-human primates, especially in regard to the new world species Callithrix jacchus (white-tufted-ear-marmoset) from northeastern Brazil, research involving use of the diaphragm in such species is nonexistent. Thus, the objective was to characterize the morphology and biometry of the diaphragm in C. jacchus of both sexes, analyzing possible structural differences between males and females. To this end, we used four adult white-tufted-ear-marmosets from a commercial breeder, two males and two females that had died of natural causes. After fixed in 10% formaldehyde solution, the animals were dissected for photo documentation, the diaphragm was collected for biometrics (length and width) with a caliper, and for histological processing by hematoxylin-eosin and Trichrome Masson. The measurements showed that there were no significant differences between males and females. The topography and the presence of three openings (foramen vena cava, aortic et esophageal hiatus) in the extension of the diaphragm corroborate descriptions in classical literature for other mammals. Regarding the histological findings, it was concluded that the muscular fibers are arranged in an organized shape, with a large diameter and basal nuclei, and showed similar characteristics of skeletal muscle in males and females.

Función del diafragma durante la colocación de cargas sobre el abdomen en sujetos normales / Study of diaphragmatic muscle function during abdominal weight in normal subjects

Los efectos de las cargas en el abdomen con el objeto de producir entrenamiento del diafragma, no han sido suficientemente evaluados. Estudiamos la función del diafragma durante la colocación de cargas sobre el abdomen y con cambios en el patrón respiratorio. Se estudiaron 6 voluntarios normales. Se obtuvo flujo en la boca, presión gástrica (Pga), presión esofágica (Pes), movimiento torácico (TX) y abdominal (AB), presión inspiratoria máxima (PImax) y presión transdiafragmática media (Pdi) y máxima (Pdimax). Se calculó la relación Pdi/Pdimax y el índice tensión-tiempo del diafragma (TTdi). Etapas: patrón normal (PN), patrón abdominal (PA) y carga de 1, 2, 4 y 6 kg con PN y PA. El PA fue facilitado por las cargas sobre el abdomen. Solo con 6 kg (PN y PA) la Pga a capacidad residual funcional aumentó significativamente (p 0.001). La Pdi siguió a las variaciones de la Pga y aumentó con todos los PA (p < 0.001). Con PA y carga el índice TTdi alcanzó un valor de 0.05 ± 0.02 (p < 0.001). Las cargas no aumentaron este índice más de lo que hizo el PA solo. Nuestros hallazgos sugieren que las cargas sobre el abdomen aumentan la propiocepción relacionada con los movimientos respiratorios y descenso del diafragma. Las cargas producen cambios leves en la mecánica del diafragma (en sujetos normales, 1/3 de la carga necesaria para desarrollar fatiga). En sujetos normales estos cambios parecen ser insuficientes para producir entrenamiento de los músculos respiratorios.

The effects of the abdominal weight with the intention of producing training of the diaphragm, have not been sufficiently evaluated. We studied the function of the diaphragm during the abdominal weight training and during associated changes in the respiratory pattern. Six normal volunteers were studied. Flow at the mouth at functional residual capacity (FRC) was obtained as well as gastric pressure (Pga), esophageal pressure (Pes), thoracic and abdominal movements, maximal inspiratory pressure and mean and maximal transdiaphragmatic pressure (Pdi and Pdi max). Pdi/Pdimax and the diaphragm tension-time index (TTdi) were calculated. Studied steps: normal pattern (NP), abdominal pattern (AP) and weight of 1, 2, 4 and 6 kg with NP and AP as well. We found 1) The AP was facilitated by the abdominal weight, 2) Only with 6 kg (NP and AP) the Pga at FRC increased significantly (p 0.001), 3) the Pdi followed the variations of the Pga and increased with all the AP (p < 0.001), 4) The index TTdi load reached a value of 0.05 ± 0.02 (p < 0.001). The charges did not increase this rate more than did the AP alone. Our findings suggest abdominal weight increases propioception related to the respiratory movements and descent of the diaphragm. The loads on the abdomen produce minor changes in mechanics of the diaphragm (1/3 of the load required to develop fatigue in normal subjects). Al least in normal subjects these changes appear to be insufficient to produce respiratory muscle training.

Effects of preoperative inspiratory muscle training in obese women undergoing open bariatric surgery: respiratory muscle strength, lung volumes, and diaphragmatic excursion

OBJECTIVE: To determine whether preoperative inspiratory muscle training is able to attenuate the impact of surgical trauma on the respiratory muscle strength, in the lung volumes, and diaphragmatic excursion in obese women undergoing open bariatric surgery. DESIGN: Randomized controlled trial. SETTING: Meridional Hospital, Cariacica/ES, Brazil. SUBJECTS: Thirty-two obese women undergoing elective open bariatric surgery were randomly assigned to receive preoperative inspiratory muscle training (inspiratory muscle training group) or usual care (control group). MAIN MEASURES: Respiratory muscle strength (maximal static respiratory pressure - maximal inspiratory pressure and maximal expiratory pressure), lung volumes, and diaphragmatic excursion. RESULTS: After training, there was a significant increase only in the maximal inspiratory pressure in the inspiratory muscle training group. The maximal expiratory pressure, the lung volumes and the diaphragmatic excursion did not show any significant change with training. In the postoperative period there was a significant decrease in maximal inspiratory pressure in both the groups. However, there was a decrease of 28 percent in the inspiratory muscle training group, whereas it was 47 percent in the control group. The decrease in maximal expiratory pressure and in lung volumes in the postoperative period was similar between the groups. There was a significant reduction in the measures of diaphragmatic excursion in both the groups. CONCLUSION: The preoperative inspiratory muscle training increased the inspiratory muscle strength (maximal inspiratory pressure) and attenuated the negative postoperative effects of open bariatric surgery in obese women for this variable, though not influencing the lung volumes and the diaphragmatic excursion.