Adaptación a un esquema de entrenamiento físico en pacientes con enfermedad pulmonar obstructiva crónica avanzada / Adaptation to a physical training protocol of severe chronic obstructive pulmonary disease patients

El ejercicio físico es un elemento básico en la rehabilitación en pacientes con EPOC. Sin embargo, los resultados son variables, lo que puede deberse a las diferentes estrategias de entrenamiento utilizadas. En 22 pacientes con EPOC avanzada (VEF, 35,6 ñ 15,7 por ciento: edad 63 ñ 15 años; x ñ DS) Evaluamos su adaptación a un esquema de entrenamiento (E) en bicicleta ergométrica que consistió en aplicar inicialmente una carga inicial de 30 por ciento de la máxima previamente determinada (CM) y aumentarla en 15 a 20 por ciento en las sesiones siguientes cuando el paciente era capaz de mantenerla por 45 minutos, hasta alcanzar la meta de 75 por ciento de la CM. La intensidad del E se midió en watts calculando el área bajo la curva de la relación entre las cargas aplicadas y el número de sesiones de entrenamiento. El efecto del E se evaluó a través de los cambios en la carga y el VO2 máximos, la duración de un ejercicio submáximo, la frecuencia cardíaca, (FC), disnea, fatiga de las extremidades inferiores y lactato sanguíneo para una misma carga y tiempo de ejercicio. La CM de E fue 61 ñ 23 por ciento (x ñ DS) del máximo. Seis pacientes no fueron capaces de alcanzar la carga establecida como meta. En los restantes ésta se alcanzó en un número variable de sesiones (12 ñ 7). La intensidad del entrenamiento fue de 952 ñ 325 watt. El E produjo un aumento de la CM (p<0,02) y del tiempo de ejercicio (p<0,0001) y una disminución significativa de la FC, disnea, fatigabilidad y lactato sanguíneo. La duración del ejercicio se correlacionó con la reducción de la disnea (r= -0,448; p<0,05) y la intensidad del entrenamiento con la disminución de la fatiga (r= -0,5176; p = 0,014) y también del lactato sanguíneo (r= -0,488; p = 0,021). Los resultados demuestran que aún cuando la adaptación al esquema de entrenamiento fue variable de acuerdo a la capacidad individual y no pudo ser aplicada a todos los pacientes, la mayoría de ellos obtuvo efectos beneficiosos

Análisis acústico de las sibilancias en lactantes con obstrucción bronquial aguda: estudio de seguimiento / Acoustic analysis in wheezy infants: a follow up study

Background: There is some information about wheeze characteristics in infants, however it is not clear whether the different wheeze patterns relates to prognosis and evolution during the first two years of life. Objectives: To characterize wheezing and spectral pattern of lung sounds in infants with acute bronchiolitis (AB) and in infants with recurrent wheeze (RW) as well as to compare these parameters with the clinical evolution 2 years after admission. Methods: Seventy six AB infants (48 boys), aged 5.5ñ0.7 months (mean ñ SD), 62 RSV (+) and 32 RW infants (20 boys), aged 11.4ñ2 months were studied during the first week of admission at the hospital. Patients were studied during spontaneous sleep, breathing with a face mask connected to a pneumotachograph at flows of 0.1ñ0.02L/s. Sounds were registered at baseline and 20 minutes after salbutamol using 2 contact sensors placed at both lower lobes levels. Signals were low-pass filtered, amplified and a Fourier analysis was applied to sounds within a target flow range. Spectral analysis was done between 100 and 1000 HZ. Results: In 40/76 (53 percent) AB vs 30/34 (88 percent) RW sinusoidal wheezing (p <0.01; chi2) were observed and a positive bronchodilator response was obtained in 37/76 (49 percent) AB vs 32/34 (94 percent) RW (p <0.01; _2). Patients with sinusoidal wheezing (s-w) had more wheezing episodes in follow-up, 26/40 vs 8/36 in complex wheezing (c-w), (p <0.01: _2) and 30/34 in RW (p <0.01; _2). IgE values at 18 months were higher in s-w compared to c-w (63ñ7 vs 24ñ5 Iu/mL (p <0.01) and 96ñ11 Iu/mL in RW (p <0.01). Conclusions: a) Wheezing characteristics in acute bronchiolitis vs recurrent wheezing are different; b) Bronchodilator response relates to wheeze characteristics and c) Higher IgE and more recurrent wheezing episodes are seen in acute bronchiolitis with sinusoidal wheezing. These findings suggest that lung sounds analysis is useful in assessing wheezy patients and have a value to identify infants on risk of developing asthma

Análisis computacional de los ruidos respiratorios en la evaluación de la obstrucción bronquial en niños pequeños que no colaboran con las pruebas espirométricas / Acoustic analysis of respiratory sounds during methacholine challenge in preschool children

Background: There are changes in inspiratory breath sound intensity in patients with airway obstruction. Airway narrowing may change sound spectral characteristics. Aim: To define the characteristics of lung sounds at standardized air flow during methacholine challenge and to compare acoustic changes with transcutaneous oxygen tension (PtcO2) during induced airway narrowing. Patients and methods: Forty asthmatic children (20 male) aged 5.2ñ1 years and 40 normal children (18 male), aged 5.6 ñ 1 years were studied. All patients were free of respiratory tract infections one month before the study. A methacholine challenge from 0.06 to 8 mg/ml was performed; the test was ended when a fall in PtcO2 of >20 percent from baseline was observed or if the final concentration was reached. Subjects breathed through a pneumotachograph aiming at flows of 0.4 to 0.6 l/s. Respiratory sounds were recorded using contact sensors at the suprasternal notch and at the posterior right lower lobe. From average spectra, power at low (100-200 Hz=P1) and high frequencies (400-2000 =P2) was calculated. Frequencies below which 50 percent (F50) and 99 percent (SEF90) of the spectral power between 100 and 2000 Hz was contained, were also calculated. Results: In asthmatics, the metacholine concentration at which a 20 percent fall in PtcO2 was observed, was lower than in normal children (p< 0.05). There was an increase in P1 (p<0.01) and a reduction in P2 (p<0.01) during inspiration, in subjects that experienced a 20 percent reduction in PtcO2. Also, there was an increase in F50 and SEF99 during inspiration in lung sounds, but not over the trachea. Conclusions: Lung sounds analysis can be useful for the assessment of airway reactivity in asthmatic children

Efecto de la prueba de la caminata de seis minutos sobre la hiperinflación pulmonar en pacientes con enfermedad pulmonar obstructiva crónica avanzada / The six minute walking test elicits dynamic hyperinflation in severe COPD patients

Background: Exercise tolerance in patients with COPD is highly variable and poorly related to airways obstruction assessed by FEV1. These patients develop dynamic hyperinflation (DH) during an incremental exercise test which can be evaluated through a reduction in inspiratory capacity (IC). Aim: to evaluate: a) if the six minute walking test (6 MWD) induce DH reducing IC, b) if the reduction in IC is related to tidal expiratory flow limitation at rest (FL). Subjects and methods: Thirty eight stable COPD patients (28 FL and ten non FL during resting breathing, determined by the negative pressure technique). Inspiratory capacity was measured before and immediately after the 6 MWD test. Dyspnea, SpO2 and heart rate were measured before and after the test. Results: Inspiratory capacity was lower in FL patients as compared to patients without FL (p <0,005). Although no differences were found between groups in 6 MWD, dyspnea and HR, a significant reduction in IC after the walking test was observed only in FL patients (p <0,0001). In addition, SpO2 fell significantly (p <0,0001) after walking in the same group. Conclusions: Our results demonstrate that a moderate exercise such as the walking test induces DH and hypoxemia in patients with COPD and FL and stresses the importance of assessing DH by measuring IC in these patients

Calidad de vida en pacientes con enfermedad pulmonar obstructiva crónica e impacto del entrenamiento físico / Quality of life in patients with chronic pulmonary obstructive disease and the impact of physical training

Background: Health related quality of life (QoL) is severely impaired in COPD patients as a consequence of dyspnea and limited exercise tolerance, which lead to physical deconditioning and muscle atrophy resulting in weakness and fatigue. Psychosocial factors such as depression and anxiety also contribute to this impairment. Aim: To evaluate: a) the impact of COPD on quality of life, and b) the effect of 10 weeks of exercise training on exercise performance and on QoL. Patients and methods: The Spanish version of the Chronic Respiratory Questionnaire (CRQ) was applied to 55 COPD patients (FEV1 37 ñ 13 percent pred) for the assessment of QoL and in 30 of them submitted to exercise training for 10 weeks. Exercise performance was evaluated by measuring: six-minute walking distance, maximal workload (Wmax), maximal O2 consumption (VO2max) as well as endurance time, blood lactic acid, dyspnea and leg fatigue during a submaximal exercise. Trained patients were evaluated before and after training. Results : COPD patients showed a reduction (mean ñ SD) in the four domains of the CRQ: dyspnea (3.1 ñ 0.9); fatigue (4.3 ñ 1.3); mastery (4.65 ñ 1.3), emotional function (4.1 ñ 0.97), and in Wmax and VO2max (52 ñ 16 Watt and 970 ñ 301 ml/min). No significant relationship between the impairment in exercise tolerance and in QoL was observed. Exercise training significantly improved the four domains of QoL (p < 0.0001), Wmax (p < 0.05), VO2max (p < 0.02) and endurance time (p < 0.001). Isotime exercise measurements of dyspnea, leg fatigue and lactic acid decreased after training (p < 0.001, each). No significant relation between changes in QoL and changes in exercise performance were observed. Conclusions: Our results demonstrate that QoL is seriously impaired in patients with COPD and confirm: (a) the lack of relationship of QoL to the usually measured physiological parameters, and (b) the beneficial effect of exercise training on QoL through the reduction of symptoms. These findings stresses the need of measuring quality of life in our patients if we want to evaluate the impact of therapeutic procedures on well-being from the patients' perspective

Entrenamiento selectivo de los músculos respiratorios en pacientes con insuficiencia cardíaca crónica / Selective training of respiratory muscles in patients with chronic heart failure

Background: Patients with chronic heart failure have a lower inspiratory muscle strength and fatigue endurance. Aim: To assess the effects of selective training of respiratory muscles in patients with heart failure. Patients and methods : Twenty patients with stable chronic heart failure, aged 58.3 ñ 3 years with an ejection fraction of 28 ñ 9 percent, were subjected to respiratory muscle training with threshold valves. The load was fixed in 30 percent of maximal inspiratory pressure (PImax) in 11 and in 10 percent of PImax in nine. Two sessions of 15 minutes, 6 days per week, during 6 weeks were done. Degree of dyspnea (Mahler score), maximal oxygen uptake, distance walked in 6 minutes, respiratory muscle function and left ventricular ejection fraction were measured before and after training. Results: Both training loads were associated to an improvement in dyspnea (+2.7 ñ 1.8 and +2.8 ñ 1.8 score points with 30 percent Plmax and 10 percent PImax respectively), maximal oxygen uptake (from 19 ñ 3 to 21.6 ñ 5 and from 16 ñ 5 to 18.6 ñ 7 ml/kg/min with 30 percent PImax and 10 percent PImax respectively, p< 0.05), PImax (from 78 ñ 22 to 99 ñ 22 and from 72 ñ 34 to 82.3 cm H20 with 30 percent Plmax and 10 percent PImax respectively), sustained PImax (from 63 ñ 18 to 90 ñ 22 and from 58 ñ 3 to 69 ñ 3 cm H20 with 30 percent PImax and 10 percent PImax respectively), and maximal sustained load (from 120 ñ 67 to 195 ñ 47 and from 139 ñ 120 to 192 ñ 154 g with 30 percent PImax and 10 percent PImax respectively). The distance walked in 6 min only increased in subjects trained at 30 percent PImax (from 451 ñ 78 to 486 ñ 68 m). Conclusions: Selective training of respiratory muscles results in a functional improvement of patients with chronic heart failure

Potencia de los músculos inspiratorios en insuficiencia cardíaca crónica y en enfermedad pulmonar obstructiva crónica / Respiratory muscle power output in patients with chronic heart failure and patients with chronic pulmonary obstructive disease

Background: The maximal pressure generated by inspiratory muscles (PIMax) is an index of their strength which is diminished in both chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF). Although inspiratory muscle power output (IMPO), which includes both strength and velocity of shortening, has been shown to be reduced in COPD, there is no information regarding IMPO in CHF. Aim: To measure Impo in patients with CHF and COPD. Patients and methods: We studied 9 CHF patients with functional capacity II and III and 9 patients with severe COPD. Eight normal subjects of similar ages were included as controls. Power output was measured using the incremental threshold loading test. Results: Maximal IMPO was significantly reduced in both groups of patients. Power output developed with each increasing load was also diminished, basically as a consequence of a reduction in insp. The degree of dyspnea at the end of the test was greater in COPD than in CHF patients and normal subjects. For a given level of power, dyspnea was also greater in patients than in normals subjects. There was no decrease in SpO2 during the test. Conclusions: IMPO is equally reduced in COPD and CHF patients. Power output is better related to dyspnea than PIMax, probably because of the inclusion of shortening velocity

Neumonía intersticial no específica / Diffuse idiopathic interstitial lung disease

Se presenta un paciente, clínicamente calificado como broncoquiolitis obliterante con neumonía demostró una neumonía intersticial inespecífica, entidad poco frecuente, recientemente descrita, cuyo reconocimiento es importante por responder a tratamiento corticoidal, al contrario de la fibrosis intersticial usual, afección más frecuente con la cual ha sido confundida bajo la categoría clínica de fibrosis pulmonar idiopática

Ventilación mecánica no invasiva en pacientes con enfermedad pulmonar obstructiva crónica estable / Non-invasive mechanical ventilation in patients with stable chronic obstructive lung disease

Background: The benefits of non-invasive mechanical ventilation (NIMV) in hypercapnic patients with severe stable COPD remain controversial mainly due to their unknown mechanisms. Aim: To assess the clinical and physiological benefits of a 3 weeks period of intermittent NIMV and their underlying mechanisms in COPD patients. Patients and methods: Twelve patients (10 male) prospectively recruited (age 65 ñ 3 years, FEV1 27 ñ 2 percent predicted, PaO2 46 ñ 2 mmHg, PaCO2 55 ñ 2 mmHg) were submitted to NIMV using a commercially available system (BiPAP) 3 h a day, 5 days a week for 3 weeks. Arterial blood gases, 6 min walking distance, dyspnea (MahlerÕs scale), breathing pattern, PIMax, ventilatory drive (P0,1) and the impedance of the respiratory system (P0,1/VT/TI) were measured before and after NIMV. Results: A significant improvement in PaO2, PaCO2, PIMax, dyspnea and exercise capacity was observed in addition to a trend for VT to increase and for respiratory rate (RR) to decrease. The impedance of the respiratory system showed a significant reduction. Ventilatory drive, normalized for PaCO2 levels, did not change. Improvement in PaCO2 was related to an increase in VT, whereas a significant association between the reduction in RR and the fall in respiratory system impedance was also found. Conclusions: Our study supports previous data demonstrating that NIMV improves clinical and physiologic parameters in advanced stable COPD and suggest that the underlying mechanism is a reduction in the inspiratory load. A randomized clinical trial is needed to confirm that this mechanism is operative

Apnea del sueño en la insuficiencia cardíaca estable: factores predisponentes / Sleep apnea in patients with stable congestive heart failure: predisposing factors

En los pacientes con insuficiencia cardíaca crónica(ICC) se ha descrito una falta prevalencia de alteraciones ventilatorias e hipoxemia durante el sueño. Para evaluar los factores asociados a su incidencia estudiamos con polisomnografía nocturna a 14 pacientes con ICC estable y los resultados se correlacionaron con la edad, capacidad aeróbica, función ventricular y distintos parámetros de ventilación, congestión y perfusión periférica. La etiología de la ICC era isquémica en 8 e idiopática en 6 pacientes. El estudio respiratorio durante el sueño resultó anormal en 6 pacientes (43 por ciento). Ellos presentaron 37 +18 episodios de apnea/hipopnea por hora, con predomio de apneas de tipo central. En análisis univariado, resultaron predictores de apnea del sueño la menor capacidad funcional y consumo de 02 máximo, la elevación del ácido, láctico arterial y de la uricemia, y la disminución de la PaC02 en vigilia. La función ventricular izquierda y la congestión pulmonar o sistémica, no fueron predictores de apnea del sueño. Conclusión: se corrobora una alta incidencia de apnea del sueño en la ICC y de acuerdo a nuestros datos se puede identificar a los pacientes con mayor riesgo usando criterios clínicos y de laboratorio sencillos

Efecto del entrenamiento muscular inspiratorio en el costo de oxígeno de la ventilación en pacientes con enfermedad pulmonar obstructiva crónica / Effects of inspiratory muscle training on the oxygen cost of breathing in patients with chronic obstructive pulmonary disease

Background: Patients with chronic obstructive pulmonary disease have an increased inspiratory work, since they must overcome high loads due to increased airway resistance. Aim: To determine if the reduction in the metabolic cost of exercise observed in patients with chronic obstructive pulmonary disease (COPD) after inspiratory muscle training, was due to a reduction in the oxygen cost of breathing. Patients and methods: Nine patients with COPD (FEV1 39 ñ 13 percent) subjected to inspiratory muscle training, using a training load of 30 percent of maximal inspiratory pressure, during 10 weeks; 5 patients with COPD (FEV1 44 ñ 18 percent) not subjected to training, and 7 healthy controls (FEV1 110 ñ 10 percent) were studied. The cost of breathing was calculated as the difference in VO2 measured at rest and after breathing a gas mixture containing air and 5 percent CO2. Exercise VO2 was measured at submaximal exercise. Results: Oxygen cost of breathing was increased in patients with COPD and it was inversely correlated with FEV1 (r= -0.86 p<0.001). Inspiratory muscle training increased maximal inspiratory pressure and decreased exercise VO2. Oxygen cost of breathing increased in six and decreased in three trained patients. Changes in this parameter after training did not correlate with the reduction in exercise VO2 or the increment in maximal inspiratory pressure. Conclusions: The reduction in exercise VO2 after inspiratory muscle training is not due to a reduction in the oxygen cost of breathing

Metabolismo de peróxidos en músculos respiratorios: efecto del crecimiento, desarrollo y envejecimiento / Glutathione peroxidase and catalase activity in rat respiratory muscles: effect of growth, maturation and aging

Background: Glutathione peroxidase (GSHPx) and catalase are two important cellular antioxidant enzymes involved in H2O2 and lipid-peroxide metabolism. Aim: To study the effects of growth, maturation and aging on the activity of these enzymes. Material and methods: GSHPx and catalase specific activities were measured in samples of diaphragm and intercostal muscle of male Sprague-Dawley rats of different ages (21, 50, 70, 180 and 365 days), anesthetised with chloral hydrate (45 mg/100 g ip). Results: The diaphragm and intercostal muscles did not differ in GSHPx activity at 21 days. After that, GSHPx activity increased progressively with age, but following a different pattern, in each muscle, suggesting an increase in enzyme substrates with age. In one year old animals, GSHPx activity was 5 times higher for the diaphragm and 3 times higher for the intercostal muscles, when compared with values observed at 21 days of age. Catalase activity also increased with age in the diaphragm but not in the intercostal muscles. Conclusions: GSHPx activity increases progressively with age in rat respiratory muscles, with a time course that is specific of each muscle. Catalase activity increases with age only in the diaphragm. These results support the hypothesis that antioxidants in respiratory muscles undergo specific regulatory changes with age

Enfisema pulmonar experimental en la rata: fenómenos inflamatorios y progresión del daño pulmonar / Experimental pulmonary emphysema in the rat: inflammatory phenomena and progression of lung damage

Background: Although the hamster model of elastase induced emphysema is well characterized, the rat model has received less attention. Aim: To evaluate the effect of a single intratracheal elastase dose on lung pathological changes of Sprague-Dawley rats. Material and methods: Rats were injected with a single intratracheal elastase dose of 28 U/100 g body weight or saline and studied 7, 15, 30 and 365 days after injection. Results: Forty percent of rats died in the first 48 hours after injection, six were sacrificed at 7 days, 6 at 15 days, 7 at 30 days and 12 at 365 days. Progressive centroacinar emphysema was found from day 7 after elastase, with a persistent inflammatory reaction in the vicinity of emphysematous areas. Conclusions: Present findings differ from the panacinar emphysema described in the hamster using a similar elastase dose

Entrenamiento muscular inspiratorio en pacientes con enfermedad pulmonar obstructiva crónica / Inspiratory muscle training in patients with chronic obstructive pulmonary disease

We analyze the effect of inspiratory muscle training (IMT) in patients with chronic obstructive pulmonary disease (COPD), with special emphasis on its effects on inspiratory muscle function and clinical outcomes. We reviewed only randomized, controlled studies that have either controlled both the load and the breathing pattern when using resistive training or have employed a threshold trainer in which the load is independent of the pattern of breathing, since methodological aspects may explain inconsistent results in the literature. In these circumstances, most of the studies demonstrated positive effects on inspiratory muscle function. Clinical effects were seldom evaluated; limited available data showed a reduction in dyspnea that was related to an increase in maximal inspiratory pressures (PIMax). When exercise capacity was evaluated through the distance the patients were able to walk in 6 or 12 minutes, most studies demonstrated a significant increase. Other reported positive effects were improvement in nocturnal SaO2, inspiratory muscle power output and maximal inspiratory flow rate. Based in this review, a recommended training regime appears to be an intermediate load (30-40 percent PIMax) using a threshold device for 30 minutes daily for at least 5 weeks. Although in the literature the criteria for selecting patients are not always well defined, we consider IMT as a helpful procedure for pulmonar rehabilitation in those patients with a moderately severe inspiratory muscle dysfunction presenting dyspnea during daily living activities despite optimal therapy

Tensión trascutánea de oxígeno y sibilancias en la evaluación de la reactividad bronquial en niños sanos y asmáticos de 3 a 6 años / Transcutaneous oxygen tension and wheezing during methacholine challenge test in normal and asthmatic 3 to 6 years old children

La tensión transcutánea de oxígeno (tcPO,) se correlaciona con el VEF, durante la prueba de provocación con metacolina (MC). Nuestro objetivo fue evaluar la reactivídad bronquial en niños de 3 a 6 años utilizando la medición de la tcPO2 y presencia de sibilancías durante la prueba de MC. Se estudiaron 28 niños sanos (S), 13 hombres, edad 4,6 ñ 1 años (promedio ñ DS) y 32 asmáticos (A), (18 hombres) 4,6 ñ 1 años. Los niños sanos no presentaron antecedentes familiares de asma ni infección respiratoria 4 semanas antes del examen. Los asmáticos se clasificaron como leves (11), moderados (17) y severos (4). La prueba de MC se realizó duplicando la dosis desde 0,06 a 8 mg/ml según Cockroft y cols (Clín Allergy 1977;7:235). Se monitorizó a) tcPO2 con un electrodo a 44ºC en el antebrazo, b) SaO2, c) sibílancias, d) frecuencia respiratoria. La caída de un 20 por ciento de la tcPO2 desde su valor basal (PC20-tcPO2), o algún efecto adverso fueron los criterios de término de la prueba. La tcPO2 varió en el grupo de sanos desde 88 ñ 13 a 74 ñ 18 mmHg y en asmáticos desde 74 ñ 8 a 55 ñ 6 mmhg desde el valor basal al final respectivamente (p < 0,0l). Las sibílancias estuvieron presentes a 1,5 ñ 1 mg/ml de metacolina en S y a 0,3 ñ 0,3 mg/ml en A (p < 0,0l). La PC20 tcPO, fue de 1,8 ñ 1 mg/ml en S y de 0,4 ñ 0,4 mg/ml en A (p < 0,01). Las sibilancias se correfacionaron con la PC20-tcPO2 (r= 0,67; p< 0,001). La PC20-tcPO2 estuvo presente en 17/28 sanos y en 32/32 asmáticos (p < 0,001; x2). La concentración de MC de 0,75 mg/ml tuvo una sensibilidad de 91 por ciento y especificidad de 93 por ciento para detectar hiperreactividad bronquial El examen se repitió en 10 niños (4 sanos) en un lapso de 3 a 6 meses, obteniéndose valores que estuvieron dentro de un 10 por ciento de variabilidad. Se concluye que la tcPO2 y sibilancias son útiles en la evaluación de la reactívidad bronquial en asmáticos que no colaboran con las pruebas espirométrícas

Ventilación mecánica no invasiva intermitente: utilidad en el tratamiento de la insuficiencia cardíaca crónica avanzada / Non invasive intermittent mechanical ventilation: utility in the treatment of advanced chronic cardiac failure

The higher respiratory work and less inspiratory muscle strength of patients with cardiac failure may contribute to dicrease their functional capacity. To assess the effects of non invasive intermittent mechanical ventilation on clinical parameters, peropheral perfusion, cardiac and inspiratory muscle function. Patients with chronic cardiac failure, functional cpacity III-IV were subjected to 6 sessions of nasal non invasive intermittent ventilation during 4 hours or to simulated ventilation (controls). Fifteen ventilated patients and 6 controls completed the protocol. Ventilated patients improved the mahler transition score for dysnea by 4ñ1.6 points. They also improved their aerobic capacity, increasing the exercise duration from 10.9ñ4 to 12.7ñ5 min and their maximal oxygen consumption from 14.6ñ4 to 16.4ñ5.7 ml/kg/min. These patients also decreased their O2 and CO2 ventilatory equivalents. Maximal inspiratory pressure increased from 67.9ñ23.6 to 80.19ñ21.4 cm H2O, sustained maximal inspiratory pressure increased from 101.4ñ48 to 133ñ53 cm H2O and maximal endurance increased from 132ñ52 to 162ñ58 g in ventilated patients. None of these variables was modified in control patients. No changes were observed in renal function, blood volume, arterial gases, spirometry or plasma catecholamine levels in any group. Intermittent nasal ventilation or other measures to improve inspiratory muscle function may be beneficial for patients with severe cardiac failure

Efectos clínicos del entrenamiento muscular inspiratorio en pacientes con limitación crónica del flujo aéreo / Clinical effects of inspiratory muscular training in patients with chronic airway flow limitation

The clinical role of inspiratory muscular training (IMT) in chronic obstructive pulmonary disease (COPD) has not been established, because data on its clinical effect is scarce and controversial. To further investigate these aspects we studied 20 COPD patients (FEV1 37ñ3 percent P) who were randomly and double blindy trained for 30 minutes a day during 10 weeks using a threshold inspiratory trainer with either 30 percent (group 1) or 10 percent (group 2) of PIMax as a training load. The training load was cossed after each patient completed 10 weeks of training. Effects were assessed through changes in PIMax, dyspnea through the transition dyspnea index (ITD) and the respiratory effort with Borg's score. Walking capacity was measured with the six minutes walking distance test (6WD) and depression symptoms with Beck's score. Daily life activities were also assessed. Results showed that after 10 weeks of IMT, PIMax increased in both groups (p<0.05), dyspnea improved in group 1 as compared to group 2 (p<0.04), 6WD increased significantly in group 1 disclosed a significant deterioration in PIMax whereas group 2 disclosed significant improvements in PIMax, dyspnea and 6WD. We conclude that IMT using a threshold device with 30 percent PIMax is a useful procedure for the treatment of severe COPD patients