Resultados de la asincronía ventilatoria en pacientes con esfuerzo inspiratório / Outcomes of ventilatory asynchrony in patients with inspiratory effort

RESUMO Objetivo: Identificar la relación de la asincronía paciente-ventilador con el nivel de sedación y evaluar la asociación con los resultados hemogasométricos y clínicos. Métodos: Estudio prospectivo de 122 pacientes admitidos en la unidad de cuidados intensivos con > 24 horas de ventilación mecánica invasiva y esfuerzo inspiratorio. En los primeros 7 días de ventilación, diariamente se evaluó la asincronía paciente-ventilador durante 30 minutos. La asincronía paciente-ventilador severa se definió con un índice de asincronía > 10%. Resultados: Se evaluaron 339.652 ciclos respiratorios en 504 observaciones. La media del índice de asincronía fue 37,8% (desviación estándar 14,1% - 61,5%). La prevalencia de asincronía paciente-ventilador severa fue 46,6%. Las asincronías paciente-ventilador más frecuentes fueron: trigger ineficaz (13,3%), auto-trigger (15,3%), flujo insuficiente (13,5%) y ciclado demorado (13,7%). La asincronía paciente-ventilador severa se relacionó con el nivel de sedación (trigger ineficaz: p = 0,020; flujo insuficiente: p = 0,016; ciclado precoz: p = 0,023) y el uso de midazolam (p = 0,020). La asincronía paciente-ventilador severa se asoció con las alteraciones hemogasométricas. La persistencia de la asincronía paciente-ventilador severa fue un factor de riesgo independiente para fracaso en la prueba de ventilación espontánea, tiempo de ventilación, neumonía asociada al ventilador, disfunción de órganos, mortalidad en la unidad de cuidados intensivos y estadía en la unidad de cuidados intensivos. Conclusión: La asincronía paciente-ventilador es un trastorno frecuente en los pacientes críticos con esfuerzo inspiratorio. La interacción del paciente con el ventilador debe optimizarse para mejorar los parámetros hemogasométricos y los resultados clínicos. Se requieren otros estudios que confirmen estos resultados.

Abstract Objective: To identify the relationship of patient-ventilator asynchrony with the level of sedation and hemogasometric and clinical results. Methods: This was a prospective study of 122 patients admitted to the intensive care unit who underwent > 24 hours of invasive mechanical ventilation with inspiratory effort. In the first 7 days of ventilation, patient-ventilator asynchrony was evaluated daily for 30 minutes. Severe patient-ventilator asynchrony was defined as an asynchrony index > 10%. Results: A total of 339,652 respiratory cycles were evaluated in 504 observations. The mean asynchrony index was 37.8% (standard deviation 14.1 - 61.5%). The prevalence of severe patient-ventilator asynchrony was 46.6%. The most frequent patient-ventilator asynchronies were ineffective trigger (13.3%), autotrigger (15.3%), insufficient flow (13.5%), and delayed cycling (13.7%). Severe patient-ventilator asynchrony was related to the level of sedation (ineffective trigger: p = 0.020; insufficient flow: p = 0.016; premature cycling: p = 0.023) and the use of midazolam (p = 0.020). Severe patient-ventilator asynchrony was also associated with hemogasometric changes. The persistence of severe patient-ventilator asynchrony was an independent risk factor for failure of the spontaneous breathing test, ventilation time, ventilator-associated pneumonia, organ dysfunction, mortality in the intensive care unit, and length of stay in the intensive care unit. Conclusion: Patient-ventilator asynchrony is a frequent disorder in critically ill patients with inspiratory effort. The patient's interaction with the ventilator should be optimized to improve hemogasometric parameters and clinical results. Further studies are required to confirm these results.

Efectos de la expansión rápida del maxilar sobre el flujo aéreo nasal en pacientes entre 6 y 14 años de edad, con compresión maxilar, medido a través de un flujómetro nasal portátil / Effects of rapid maxillary expansion on nasal airflow of patients between 6 and 14 years of age, with maxillary compression, measured with a portable nasal flowmeter

El objetivo de nuestro estudio de tipo longitudinal prospectivo simple de medidas repetidas fue determinar la variación del flujo aéreo nasal medido con un flujómetro nasal portátil, en niños entre 6 y 14 años de edad con compresión maxilar, después de la expansión rápida del maxilar (ERM). El trabajo constó de 16 niños diagnosticados con compresión maxilar y a quienes se les indicó una disyunción maxilar rápida. Los valores de la cantidad de expansión fueron registrados y la medición del flujo inspiratorio nasal máximo (FINM) se realizó antes de la ERM (T1), inmediatamente después (T2) y al cabo de 3 meses del período de retención (T3), manteniendo las mismas condiciones iniciales. El valor máximo y el promedio de las mediciones del FINM en T2 fueron significativamente mayores que en T1 (p-valor, 0,0056) y (p-valor 0,0062) respectivamente, mientras que entre T2 y T3 no existieron tales diferencias (p-valor: 0,3021) y (p-valor: 0,3315) respectivamente. Existe un aumento significativo en los valores del FINM inmediatamente después de la expansión rápida del maxilar que se mantienen en un período de tiempo de 3 meses.

The objective of our simple prospective longitudinal type study of repeated measures, was to determine the variation of nasal airflow measured with a portable nasal flow meter, in children between 6 and 14 years of age with maxillary compression, after rapid maxillary expansion (RME). The study consisted of 16 children diagnosed with maxillary compression and those who were identified with a rapid maxillary disjunction. The values of the amount of expansion were recorded and the measurement of the peak nasal inspiratory flow (PNIF) was performed before the ERM (T1), immediately after (T2) and after 3 months of retention period (T3), maintaining the same initial conditions. Results: the value maximum and average measurements of FINM in T2 were greater than in T1 (p-value, 0.0056) and (p-value 0.0062) respectively, while between T2 and T3 there were no differences (p value: 0.3021) and (p value: 0.3315) respectively. There is a significant increase in PNIF values immediately after rapid maxillary expansion that is in a period of 3 months.

Presión inspiratoria mantenida en pacientes pediátricos traqueostomizados como indicador de tolerancia al uso de cánula tapada / Maintained inspiratory pressure in pediatric tracheostomized patients as an indicator of tolerance of capped tracheostomy

INTRODUCCIÓN: El uso prolongado de traqueostomía (TQT) conlleva a complicaciones que pueden minimizarse con una decanulación segura y temprana. La presión inspiratoria mantenida (PiMant) evalúa el comportamiento dinámico de la vía aérea en inspiración, la que puede relacionarse con la tolerancia a la oclusión de la TQT en pacientes en vía de decanulación. El OBJETIVO es el de describir la medición de PiMant y relacionar su valor con la tolerancia al uso de cánula tapada. METODOLOGÍA: Se evaluó la PiMant a 16 pacientes traqueostomizados, con vacuómetro anaeroide, registrando la moda de las presiones obtenidas, saturación de oxígeno, frecuencias respiratoria y cardíaca, uso de musculatura accesoria y estridor, a los minutos 1, 5, 10 y 15 de la oclusión de la TQT. RESULTADOS: mediana edad 60 meses, rango de presiones −2 a −40 cmH2O. Valores de PiMant > −7 cmH2O se asocian a mejor tolerancia al uso de cánula tapada. El estridor severo, asociado a aumento en frecuencia respiratoria, frecuencia cardiaca y uso de musculatura accesoria fueron los principales indicadores de fin de la prueba. CONCLUSIONES: PiMant es una prueba segura. PiMant> −7cmH2O, presentan mejor tolerancia a uso de cánula tapada.

INTRODUCTION: The prolonged use of tracheostomy leads to several complications, being necessary a prompt and safe decannulation. Maintained Inspiratory Airway Pressure (PiMant) is a functional evaluation of the dynamic changes of upper airway in inspiration which could indicate the tolerance to capped tracheostomy and adapting to this new airflow resistance, prior to decannulate. METHODS: Sixteen tracheostomized patients were evaluated with PiMant using a vacuum gauge, recording pressure value, oxygen saturation, respiratory rate, heart rate, accesory muscles use and presence of stridor during 15 minutes. RESULTS: Median age 60 months-old, pressure range −2 to −40 cmH2O. PiMant values > −7 cmH2O were associated with better tolerance to capped tracheostomy. Stridor was associated to increase of respiratory effort being the best criteria to bring to a halt the test. CONCLUSIONS: PiMant is a safe assessment, and indicates tolerance to capped tracheostomy when values > −7 cmH2O are found.

Debilidad adquirida en la unidad de cuidados intensivos. Incidencia, factores de riesgo y su asociación con la debilidad inspiratoria. Estudio de cohorte observacional / Weakness acquired in the intensive care unit. Incidence, risk factors and their association with inspiratory weakness. Observational cohort study

RESUMEN Objetivo: Conocer la incidencia acumulada y analizar los factores riesgo asociados al desarrollo de debilidad adquirida en la unidad de cuidados intensivos y su asociación con la debilidad inspiratoria. Métodos: Estudio de cohorte prospectivo en un solo centro, unidad de cuidados intensivos médico-quirúrgica polivalente. Se incluyeron pacientes adultos, que hayan requerido ventilación mecánica ≥ 24 horas entre julio de 2014 y enero de 2016. No hubo intervenciones. Se registraron datos demográficos, diagnóstico clínico y factores relacionados con el desarrollo de debilidad adquirida en la unidad de cuidados intensivos y Presión inspiratoria máxima. Resultados: Ciento once pacientes incluidos, 66 desarrollaron debilidad adquirida en la unidad de cuidados intensivos, con una incidencia acumulada del 40,5% en 18 meses. El grupo con debilidad adquirida en la unidad de cuidados intensivos presentó mayor edad (55,9 ± 17,6 versus 45.8 ± 16.7), además de más días con ventilación mecánica (7 [4 - 10] versus 4 [2 - 7,3]), más días en unidad de cuidados intensivos (15,5 [9,2 - 22,8] versus 9 [6 - 14]). Hubo más pacientes con delirio (68% versus 39%), con hiperglucemia > 3 días (84% versus 59%); y con balance positivo > 3 días (73,3% versus 37%). Todas las comparaciones fueron significativas con p < 0,05. La regresión logística múltiple identificó a la edad, la hiperglucemia ≥ 3 días, el delirio y la ventilación mecánica > 5 días como predictores independientes para debilidad adquirida en la unidad de cuidados intensivos. La presión inspiratoria máxima baja se asoció a debilidad adquirida en la unidad de cuidados intensivos (p < 0,001) y el punto de corte presión inspiratoria máxima < 36cmH2O obtuvo una sensibilidad y especificidad del 31,8% y 95,5% para clasificar al grupo con debilidad adquirida en la unidad de cuidados intensivos. Conclusión: La debilidad adquirida en la unidad de cuidados intensivos es una condición con un alta incidencia en nuestro medio. El desarrollo de debilidad adquirida en la unidad de cuidados intensivos se asoció a la edad, delirio, hiperglucemia y la ventilación mecánica > 5 días. La presión inspiratoria máxima ≥ 36cmH2O demostró un alto valor diagnóstico para descartar la presencia de debilidad adquirida en la unidad de cuidados intensivos.

ABSTRACT Objective: This paper sought to determine the accumulated incidence and analyze the risk factors associated with the development of weakness acquired in the intensive care unit and its relationship to inspiratory weakness. Methods: We conducted a prospective cohort study at a single center, multipurpose medical-surgical intensive care unit. We included adult patients who required mechanical ventilation ≥ 24 hours between July 2014 and January 2016. No interventions were performed. Demographic data, clinical diagnoses, the factors related to the development of intensive care unit -acquired weakness, and maximal inspiratory pressure were recorded. Results: Of the 111 patients included, 66 developed intensive care unit -acquired weakness, with a cumulative incidence of 40.5% over 18 months. The group with intensive care unit-acquired weakness were older (55.9 ± 17.6 versus 45.8 ± 16.7), required more mechanical ventilation (7 [4 - 10] days versus 4 [2 - 7.3] days), and spent more time in the intensive care unit (15.5 [9.2 - 22.8] days versus 9 [6 - 14] days). More patients presented with delirium (68% versus 39%), hyperglycemia > 3 days (84% versus 59%), and positive balance > 3 days (73.3% versus 37%). All comparisons were significant at p < 0.05. A multiple logistic regression identified age, hyperglycemia ≥ 3 days, delirium, and mechanical ventilation > 5 days as independent predictors of intensive care unit-acquired weakness. Low maximal inspiratory pressure was associated with intensive care unit-acquired weakness (p < 0.001), and the maximum inspiratory pressure cut-off value of < 36cmH2O had sensitivity and specificity values of 31.8% and 95.5%, respectively, when classifying patients with intensive care unit-acquired weakness. Conclusion: The intensive care unit acquired weakness is a condition with a high incidence in our environment. The development of intensive care unit-acquired weakness was associated with age, delirium, hyperglycemia, and mechanical ventilation > 5 days. The maximum inspiratory pressure value of ≥ 36cmH2O was associated with a high diagnostic value to exclude the presence of intensive care unit -acquired weakness.

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.

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.

Inspiratory muscle training and functional capacity in patients undergoing cardiac surgery

Abstract Introduction: Cardiac surgery is a highly complex procedure which generates worsening of lung function and decreased inspiratory muscle strength. The inspiratory muscle training becomes effective for muscle strengthening and can improve functional capacity. Objective: To investigate the effect of inspiratory muscle training on functional capacity submaximal and inspiratory muscle strength in patients undergoing cardiac surgery. Methods: This is a clinical randomized controlled trial with patients undergoing cardiac surgery at Instituto Nobre de Cardiologia. Patients were divided into two groups: control group and training. Preoperatively, were assessed the maximum inspiratory pressure and the distance covered in a 6-minute walk test. From the third postoperative day, the control group was managed according to the routine of the unit while the training group underwent daily protocol of respiratory muscle training until the day of discharge. Results: 50 patients, 27 (54%) males were included, with a mean age of 56.7±13.9 years. After the analysis, the training group had significant increase in maximum inspiratory pressure (69.5±14.9 vs. 83.1±19.1 cmH2O, P=0.0073) and 6-minute walk test (422.4±102.8 vs. 502.4±112.8 m, P=0.0031). Conclusion: We conclude that inspiratory muscle training was effective in improving functional capacity submaximal and inspiratory muscle strength in this sample of patients undergoing cardiac surgery.

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.

High-Intensity Inspiratory Protocol Increases Heart Rate Variability in Myocardial Revascularization Patients

Abstract Objective: To evaluate heart rate variability during an inspiratory muscle endurance protocol at three different load levels [30%, 60% and 80% of maximal inspiratory pressure], in patients who had previously undergone coronary artery bypass grafting. Methods: Nineteen late postoperative myocardial revascularization patients participating in a cardiovascular rehabilitation program were studied. Maximal inspiratory pressure maneuvers were performed. An inspiratory muscle endurance protocol at 30%, 60% and 80% of maximal inspiratory pressure was applied for four minutes each, in random order. Heart rate and RR intervals were recorded and heart rate variability was analyzed by time (RMSSD-the mean of the standard deviations for all R-R intervals, and RMSM-root-mean square differences of successive R-R intervals) and frequency domains indices (high and low frequency) in normalized units. ANOVA for repeated measurements was used to compare heart rate variability indices and Student t-test was used to compare the maximal inspiratory pressure and maximal expiratory pressure values. Results: Heart rate increased during performance of maximal respiratory pressures maneuvers, and the maximal inspiratory pressure and maximal expiratory pressure mean values were significantly lower than predicted values (P <0.05). RMSSD increased significantly at 80% in relation to rest and 30% of maximal inspiratory pressure and RMSM decreased at 30% and 60% of maximal inspiratory pressure in relation to rest (P <0.05). Additionally, there was significant and progressive decrease in low frequency and increase in high frequency at 30%, 60% and 80% of maximal inspiratory pressure in relation to the resting condition. Conclusion: These results suggest that respiratory muscle training at high intensities can promote greater parasympathetic activity and it may confer important benefits during a rehabilitation program in post-coronary artery bypass grafting.

Validation of scores of use of inhalation devices: valoration of errors / Validação de escores de uso de dispositivos para inalação: valoração dos erros cometidos

AbstractObjective: To validate two scores quantifying the ability of patients to use metered dose inhalers (MDIs) or dry powder inhalers (DPIs); to identify the most common errors made during their use; and to identify the patients in need of an educational program for the use of these devices.Methods: This study was conducted in three phases: validation of the reliability of the inhaler technique scores; validation of the contents of the two scores using a convenience sample; and testing for criterion validation and discriminant validation of these instruments in patients who met the inclusion criteria.Results: The convenience sample comprised 16 patients. Interobserver disagreement was found in 19% and 25% of the DPI and MDI scores, respectively. After expert analysis on the subject, the scores were modified and were applied in 72 patients. The most relevant difficulty encountered during the use of both types of devices was the maintenance of total lung capacity after a deep inhalation. The degree of correlation of the scores by observer was 0.97 (p < 0.0001). There was good interobserver agreement in the classification of patients as able/not able to use a DPI (50%/50% and 52%/58%; p < 0.01) and an MDI (49%/51% and 54%/46%; p < 0.05).Conclusions: The validated scores allow the identification and correction of inhaler technique errors during consultations and, as a result, improvement in the management of inhalation devices.

ResumoObjetivo: Validar dois escores para medir a habilidade de pacientes em utilizar inaladores pressurizados (IPs) ou inaladores de pó (IPos), verificar os erros mais comuns na sua utilização e identificar os pacientes que necessitam de um programa educacional para o uso desses dispositivos.Métodos: Este estudo foi realizado em três etapas: validação da confiabilidade dos escores de uso dos dispositivos inalatórios; validação do conteúdo dos escores utilizando-se uma amostra de conveniência; e realização de testes para a validação de critério e a validação discriminante desses instrumentos em pacientes que preenchiam os critérios de inclusão do estudo.Resultados: A amostra de conveniência foi composta por 16 pacientes, e houve discordância interobservador em 19% e 25% para os escores de IPo e IP, respectivamente. Após a análise de expertos no assunto, os escores sofreram modificações e foram aplicados em 72 pacientes. A dificuldade mais relevante no uso de ambos os dispositivos foi a manutenção da capacidade pulmonar total após inspiração profunda. O grau de correlação dos escores por observador foi de 0,97 (p < 0,0001). Houve boa concordância interobservador na classificação dos pacientes como aptos/não aptos para uso de IPo (50%/50% e 52%/58%; p < 0,01) e de IP (49%/51% e 54%/46%; p < 0,05).Conclusões: Os escores validados permitem identificar e corrigir os erros da técnica inalatória ao longo das consultas e, em consequência, melhorar o manejo dos dispositivos para inalação.

Within-breath respiratory impedance and airway obstruction in patients with chronic obstructive pulmonary disease

OBJECTIVE: Recent work has suggested that within-breath respiratory impedance measurements performed using the forced oscillation technique may help to noninvasively evaluate respiratory mechanics. We investigated the influence of airway obstruction on the within-breath forced oscillation technique in smokers and chronic obstructive pulmonary disease patients and evaluated the contribution of this analysis to the diagnosis of chronic obstructive pulmonary disease. METHODS: Twenty healthy individuals and 20 smokers were assessed. The study also included 74 patients with stable chronic obstructive pulmonary disease. We evaluated the mean respiratory impedance (Zm) as well as values for the inspiration (Zi) and expiration cycles (Ze) at the beginning of inspiration (Zbi) and expiration (Zbe), respectively. The peak-to-peak impedance (Zpp=Zbe-Zbi) and the respiratory cycle dependence (ΔZrs=Ze-Zi) were also analyzed. The diagnostic utility was evaluated by investigating the sensitivity, the specificity and the area under the receiver operating characteristic curve. ClinicalTrials.gov: NCT01888705. RESULTS: Airway obstruction increased the within-breath respiratory impedance parameters that were significantly correlated with the spirometric indices of airway obstruction (R=−0.65, p<0.0001). In contrast to the control subjects and the smokers, the chronic obstructive pulmonary disease patients presented significant expiratory-inspiratory differences (p<0.002). The adverse effects of moderate airway obstruction were detected based on the Zpp with an accuracy of 83%. Additionally, abnormal effects in severe and very severe patients were detected based on the Zm, Zi, Ze, Zbe, Zpp and ΔZrs with a high degree of accuracy (>90%). CONCLUSIONS: We conclude the following: (1) chronic obstructive pulmonary disease introduces higher respiratory cycle dependence, (2) this increase is proportional to airway obstruction, and (3) ...

Variability of the perception of dyspnea in healthy subjects assessed through inspiratory resistive loading / Variabilidade da percepção da dispneia medida através de um sistema de cargas resistivas inspiratórias em indivíduos saudáveis

Objective: Few studies have evaluated the variability of the perception of dyspnea in healthy subjects. The objective of this study was to evaluate the variability of the perception of dyspnea in healthy subjects during breathing against increasing inspiratory resistive loads, as well as to assess the association between the level of perception of dyspnea and the level of physical activity. Methods: This was a cross-sectional study involving healthy individuals 16 years of age or older. Subjects underwent inspiratory resistive loading testing, in which the level of perception of dyspnea was quantified with the modified Borg scale. We also determined body mass indices (BMIs), assessed maximal respiratory pressures, performed pulmonary function tests, applied the international physical activity questionnaire (IPAQ)-long form, and conducted six-minute walk tests (6MWTs). The level of perception of dyspnea was classified as low (Borg score < 2), intermediate (Borg score, 2-5), or high (Borg score > 5). Results: We included 48 healthy subjects in the study. Forty-two subjects completed the test up to a load of 46.7 cmH2O/L/s. The level of perception of dyspnea was classified as low, intermediate, and high in 13, 19, and 10 subjects, respectively. The level of perception of dyspnea was not significantly associated with age, gender, BMI, IPAQ-long form score, maximal respiratory pressures, or pulmonary function test results. Conclusions: The scores for perceived dyspnea induced by inspiratory resistive loading in healthy subjects presented wide variability. The perception of dyspnea was classified as low in 31% of the subjects, intermediate in 45%, and high in 24%. There was no association between the level of perception of dyspnea and the level of physical activity (IPAQ or six-minute walk distance). .

Objetivo: Poucos estudos avaliaram a variabilidade da percepção da dispneia em indivíduos saudáveis. O objetivo deste estudo foi avaliar a variabilidade da percepção da dispneia em indivíduos saudáveis através do uso de cargas resistivas inspiratórias crescentes, assim como avaliar a associação entre o nível de percepção da dispneia e o nível de atividade física. Métodos: Estudo transversal realizado em indivíduos saudáveis com idade ≥ 16 anos. Os indivíduos foram submetidos ao teste de cargas resistivas inspiratórias, no qual o nível de percepção da dispneia foi quantificado pela escala de Borg modificada. Foram também determinados os índices de massa corpórea (IMC), pressões respiratórias máximas, testes de função pulmonar, international physical activity questionnaire (IPAQ)-long form, e testes de caminhada de seis minutos (TC6). Os indivíduos foram classificados em percepção baixa (Borg < 2), intermediária (Borg, 2-5) e alta (Borg > 5). Resultados: Foram incluídos no estudo 48 indivíduos saudáveis. Desses, 42 completaram o teste até a carga de 46,7 cmH2O/l/s. O nível de percepção da dispneia foi classificado como baixo, intermediário e alto em 13, 19 e 10 indivíduos, respectivamente. Não houve associações significativas do nível de percepção da dispneia com idade, sexo, IMC, IPAQ e testes de função pulmonar. Conclusões: Os escores da percepção da dispneia induzida por cargas resistivas inspiratórias em indivíduos saudáveis apresentaram uma ampla variabilidade. A percepção da dispneia foi classificada como baixa, intermediária e alta em 31%, 45% e 24%, respectivamente. Não houve associações entre o nível de percepção da dispneia e o nível de atividade física (IPAQ ou distância no TC6). .

Diagnostic methods to assess inspiratory and expiratory muscle strength / Métodos diagnósticos para avaliação da força muscular inspiratória e expiratória

Impairment of (inspiratory and expiratory) respiratory muscles is a common clinical finding, not only in patients with neuromuscular disease but also in patients with primary disease of the lung parenchyma or airways. Although such impairment is common, its recognition is usually delayed because its signs and symptoms are nonspecific and late. This delayed recognition, or even the lack thereof, occurs because the diagnostic tests used in the assessment of respiratory muscle strength are not widely known and available. There are various methods of assessing respiratory muscle strength during the inspiratory and expiratory phases. These methods are divided into two categories: volitional tests (which require patient understanding and cooperation); and non-volitional tests. Volitional tests, such as those that measure maximal inspiratory and expiratory pressures, are the most commonly used because they are readily available. Non-volitional tests depend on magnetic stimulation of the phrenic nerve accompanied by the measurement of inspiratory mouth pressure, inspiratory esophageal pressure, or inspiratory transdiaphragmatic pressure. Another method that has come to be widely used is ultrasound imaging of the diaphragm. We believe that pulmonologists involved in the care of patients with respiratory diseases should be familiar with the tests used in order to assess respiratory muscle function.Therefore, the aim of the present article is to describe the advantages, disadvantages, procedures, and clinical applicability of the main tests used in the assessment of respiratory muscle strength.

O acometimento da musculatura ventilatória (inspiratória e expiratória) é um achado clínico frequente, não somente nos pacientes com doenças neuromusculares, mas também nos pacientes com doenças primárias do parênquima pulmonar ou das vias aéreas. Embora esse acometimento seja frequente, seu reconhecimento costuma ser demorado porque seus sinais e sintomas são inespecíficos e tardios. Esse reconhecimento tardio, ou mesmo a falta de reconhecimento, é acentuado porque os exames diagnósticos usados para a avaliação da musculatura respiratória não são plenamente conhecidos e disponíveis. Usando diferentes métodos, a avaliação da força muscular ventilatória é feita para a fase inspiratória e expiratória. Os métodos usados dividem-se em volitivos (que exigem compreensão e colaboração do paciente) e não volitivos. Os volitivos, como a medida da pressão inspiratória e expiratória máximas, são os mais empregados por serem facilmente disponíveis. Os não volitivos dependem da estimulação magnética do nervo frênico associada a medida da pressão inspiratória na boca, no esôfago ou transdiafragmática. Finalmente, outro método que vem se tornando frequente é a ultrassonografia diafragmática. Acreditamos que o pneumologista envolvido nos cuidados a pacientes com doenças respiratórias deve conhecer os exames usados na avaliação da musculatura ventilatória. Por isso, o objetivo do presente artigo é descrever as vantagens, desvantagens, procedimentos de mensuração e aplicabilidade clínica dos principais exames utilizados para avaliação da força muscular ventilatória.

General Factors of the Korean Exposure Factors Handbook / 예방의학회지

Risk assessment considers the situations and characteristics of the exposure environment and host. Various physiological variables of the human body reflects the characteristics of the population that can directly influence risk exposure. Therefore, identification of exposure factors based on the Korean population is required for appropriate risk assessment. It is expected that a handbook about general exposure factors will be used by professionals in many fields as well as the risk assessors of the health department. The process of developing the exposure factors handbook for the Korean population will be introduced in this article, with a specific focus on the general exposure factors including life expectancy, body weight, surface area, inhalation rates, amount of water intake, and soil ingestion targeting the Korean population. The researchers used national databases including the Life Table and the 2005 Time Use Survey from the National Statistical Office. The anthropometric study of size in Korea used the resources provided by the Korean Agency for Technology and Standards. In addition, direct measurement and questionnaire surveys of representative samples were performed to calculate the inhalation rate, drinking water intake, and soil ingestion.

Acute effects of different inspiratory resistive loading on heart rate variability in healthy elderly patients

BACKGROUND: The cardiovascular system is noticeably affected by respiration. However, whether different inspiratory resistive loading intensities can influence autonomic heart rate (HR) modulation remains unclear. OBJECTIVE: The objective was to investigate HR modulation at three different inspiratory resistive loading intensities in healthy elderly men. METHOD: This was a prospective, randomized, double-blind study that evaluated 25 healthy elderly men. Cardiac autonomic modulation was assessed using heart rate variability (HRV) indices. All of the volunteers underwent maximal inspiratory pressure (MIP) measurements according to standardized pulmonary function measurements. Three randomly-applied inspiratory resistive loading (30, 60 and 80% of MIP) intensities were then applied using an inspiratory resistance device (POWERbreathe, Southam, UK), during which the volunteers were asked to inhale for 2 seconds and exhale for 3 seconds and complete 12 breaths per minute. Each effort level was performed for 4 minutes, and HR and the distance between 2 subsequent R waves of electrocardiogram (R-R intervals) were collected at rest and at each intensity for further HRV analysis. RESULTS : The parasympathetic HRV (rMSSD, SD1 and HF) indices demonstrated lower values at 80% (rMSSD: 19±2 ms, SD1: 13±2 ms and HF: 228±61 ms2) than at 30% MIP (rMSSD: 25±3 ms, SD1: 18±2 ms and HF: 447±95 ms2; p<0.05). CONCLUSIONS: Lower inspiratory resistive loading intensities promoted a marked and positive improvement of parasympathetic sinus node modulation. .

Evaluation of breathing exercise in hormonal and immunological responses in patients undergoing abdominal surgery

PURPOSE: To evaluate the effects of sustained deep inspiration in the prevention of postoperative pulmonary complications, the hormonal and immunological responses in patients submitted to abdominal surgery. METHODS: This randomized clinical trial study included 75 patients submitted to abdominal surgery, of which 36 were randomly allocated in the experimental group and underwent sustained deep inspiration during five seconds, in three sets of ten repetitions per day. The others 39 patients were allocated in the control group and were not submitted to any breathing exercise. The following parameters were measured preoperatively, 24h and 48h postoperatively: chest x-ray, serum ACTH, cortisol, IL-4, IL-10, TNF-α, forced expiratory volume in first second (FEV1), forced expiratory flow 25-75% (FEF 25-75), forced vital capacity (FVC), paO2 and paCO2. RESULTS: Mean serum cortisol in patients of the experimental and control groups before surgery were 12.8 mcg/dl (4.6-50) and 10.48 mcg/dl (1-29.1), respectively (p=0.414). The experimental group had significantly increase in serum cortisol levels, 23.6 mcg/dl (9.3-45.8), especially 24h postoperatively (p=0.049). CONCLUSION: Sustained deep inspiration in patients submitted to abdominal surgery determined important changes in serum cortisol, however, without significantly influence the postoperative pulmonary complications and the endocrine and immune responses.

The panic disorder respiratory ratio: a dimensional approach to the respiratory subtype

OBJECTIVE: The respiratory ratio is a dimensional construct of the respiratory subtype of panic disorder (PD). The respiratory subtype has been correlated with an increased sensitivity to CO2 inhalation, positive family history of PD and low comorbidity with depression. The objective of our study was to determine whether the respiratory ratio is correlated with CO2-induced panic attacks and other clinical and demographic features. METHODS: We examined 91 patients with PD and submitted them to a double-breath 35% CO2 challenge test. The respiratory ratio was calculated based on the Diagnostic Symptom Questionnaire (DSQ) scores recorded in a diary in the days preceding the CO2 challenge. The scores of the respiratory symptoms were summed and divided by the total DSQ score. RESULTS: The respiratory ratio was correlated with CO2 sensitivity, and there was a non-statistically significant trend towards a correlation with a family history of PD. CONCLUSIONS: The positive correlation between the respiratory ratio and the anxiety elicited by the CO2 inhalation indicates that the intensity of respiratory symptoms may be proportional to the sensitivity to carbon dioxide.

Evaluation of maximal inspiratory and sniff nasal inspiratory pressures in pre- and postoperative myocardial revascularization / Avaliação das pressões inspiratória máxima e inspiratória nasal sniff no pré e pós-operatório de revascularização do miocárdio

OBJECTIVE: The objective of this study was to evaluate and correlate inspiratory muscle strength using maximal inspiratory pressure (MIP) and sniff nasal inspiratory pressure (Pnsn) in patients with coronary artery disease in pre- and postoperative of myocardial revascularization surgery. METHODS: Thirty-eight men were studied, divided into a control group (CG) comprised of healthy individuals (n=18), age 55.52 ± 7.8 years and a myocardial revascularization group (MRG), comprised of patients with coronary artery disease submitted to myocardial revascularization (n=20), age 58.44 ± 9.3 years. All volunteers were submitted to MIP and Pnsn measurement, and the MRG was evaluated in the preoperative period and on the first postoperative day (PO1). RESULTS: MRG presented MIP (80.60 ± 26.60 cmH2O) and Pnsn (74.70 ± 31.80 cmH2O) values inferior to CG (MIP: 112.22 ± 32.00 cmH2O; Pnsn: 103.70 ± 34.10 cmH2O), and there was significant reduction of these values on PO1 (MIP: 40.05 ± 15.70 cmH2O; Pnsn: 40.05 ± 16.60 cmH2O). There was correlation and concordance between evaluation methods in both groups studied, as well as in pre- and postoperative MRG conditions. CONCLUSIONS: The results showed that the studied patients presented reduced MIP and Pnsn pre- and post-operative myocardial revascularization. Also, the Pnsn correlated with MIP and can be considered suitable for assessing inspiratory muscle strength in this population.

OBJETIVO: O objetivo deste estudo foi avaliar e correlacionar a força muscular inspiratória, pelas medidas da pressão inspiratória máxima (PImáx) e pressão inspiratória nasal sniff (Pnsn), em pacientes com doença arterial coronariana no pré e pós-operatório de revascularização do miocárdio. MÉTODOS: Foram estudados 38 homens, divididos em grupo controle (GC), composto por indivíduos saudáveis (n=18), idade 55,52 ± 7,8 anos, e grupo revascularização do miocárdio (GRM), composto por pacientes com doença arterial coronariana submetidos à revascularização do miocárdio (n=20), idade 58,44 ± 9,3 anos. Todos os voluntários foram submetidos à mensuração da PImáx e da Pnsn, sendo o GRM avaliado no pré (pré-op) e primeiro pós-operatório (PO1). RESULTADOS: O GRM apresentou valores de PImáx (80,60 ± 26,60 cmH2O) e Pnsn (74,70 ± 31,80 cmH2O) inferiores ao GC (PImáx: 112,22 ± 32,00 cmH2O; Pnsn: 103,70 ± 34,10 cmH2O), ocorrendo ainda redução significativa destes valores no PO1 (PImáx: 40,05 ± 15,70 cmH2O; Pnsn: 40,05 ± 16,60 cmH2O). Houve correlação e concordância entre os métodos de avaliação nos dois grupos estudados, assim como nas condições pré e pós-operatória do GRM. CONCLUSÃO: Os resultados demonstraram que os pacientes estudados apresentaram redução da PImáx e da Pnsn no pré e pós-operatório de revascularização do miocárdio, e que a Pnsn correlacionou-se com a PImáx, sendo adequada para avaliar a força muscular inspiratória nessa população.

Valores de referência da pressão inspiratória nasal em indivíduos saudáveis no Brasil: estudo multicêntrico / Reference values for sniff nasal inspiratory pressure in healthy subjects in Brazil: a multicenter study

OBJETIVO: Os objetivos do presente estudo foram determinar equações de referência para pressão inspiratória nasal (PIN) e propor equações de referência para a população brasileira. MÉTODOS: Foram avaliados 243 indivíduos saudáveis (111 homens e 132 mulheres), entre 20 e 80 anos, com CVF > 80% e razão VEF1/CVF > 85% do predito. Todos os indivíduos realizaram testes de força muscular respiratória para a determinação de PIN, PImáx e PEmáx. RESULTADOS: Os valores da PIN foram maiores no sexo masculino que no feminino (p < 0,05), e a PIN apresentou correlação negativa com a idade para homens (r = -0,29; p < 0,001) e mulheres (r = -0,33; p < 0,0001). A análise de regressão linear múltipla também revelou que a idade permaneceu exercendo influência na predição da PIN em homens (R² = 0,09) e mulheres (R² = 0,10). Os valores preditos da PIN encontrados foram superiores àqueles obtidos em outras populações. CONCLUSÕES: Nesse contexto, sugerem-se equações preditivas para PIN em indivíduos brasileiros saudáveis na faixa etária entre 20 e 80 anos, com o intuito de minimizar discrepâncias diagnósticas ao comparar indivíduos.

OBJECTIVE: The objectives of this study were to determine reference values for sniff nasal inspiratory pressure (SNIP) and to propose reference equations for the population of Brazil. METHODS: We evaluated 243 healthy individuals (111 males and 132 females), between 20 and 80 years of age, with an FVC and FEV1/FVC ratio > 80% and > 85% of the predicted value, respectively. All of the subjects underwent respiratory muscle strength tests to determine MIP, MEP, and SNIP. RESULTS: We found that SNIP values were higher in males than in females (p < 0.05) and that SNIP correlated negatively with age, for males (r = -0.29; p < 0.001) and for females (r = -0.33; p < 0.0001). Linear regression also revealed that age influenced the predicted SNIP, for males (R² = 0.09) and females (R² = 0.10). We obtained predicted SNIP values that were higher than those obtained for other populations. CONCLUSIONS: We have devised predictive equations for SNIP to be used in adults (20-80 years of age) in Brazil. These equations could help minimize diagnostic discrepancies among individuals.

Does nitric oxide improve left ventricular dysfunction complicated with refractory hypoxemia after CABG surgery?

Nitric oxide [NO] may improve left ventrcular dysfunction after cardiac surgery. We have reported a case of severe left ventricular dysfunction and refractory hypoxemia after a two-vessel coronary artery grafting surgery. Different protective ventilation strategies and circulatory support with infusions of epinephrine and dopamine and intra-aortic balloon pumping failed to induce improvements in the cardiopulmonary function. In light of the worsening myocardial function and refractory hypoxemia, inhaled NO 20 ppm was initiated. This was followed by a progressive rapid improvement in the left ventricular function and oxygenation index, and gradual resolution of radiological lung infiltrates. The use of NO inhalation can be a safe and effective treatment modality for the refractory left ventricular dysfunction and worsening hypoxemia after coronary artery bypass grafting [CABG] surgery