Combined effects of mild-to-moderate obesity and asthma on physiological and sensory responses to exercise.

Despite the close link between asthma and obesity, there are no studies that have evaluated the sensory and physiological responses to exercise in obese asthmatics. We recently demonstrated that normal weight asthmatics with well controlled disease have preserved cardiorespiratory and sensory responses to exercise relative to non-asthmatic controls. However, these similarities may not hold true in patients with combined obesity and asthma. Accordingly, we sought to determine if combined asthma and obesity was associated with deleterious effects on cardiorespiratory fitness, exercise performance, dyspnoea, and physiological responses to exercise. Fourteen well-controlled obese asthmatics and fourteen age-matched normal weight asthmatics performed routine spirometry and underwent an incremental cardiopulmonary cycle test to assess the ventilatory, pulmonary gas exchange, cardiovascular, and sensory responses to exercise. Groups were well matched for age, height, spirometry, and asthma control. Obese asthmatics had a significantly greater body mass index (33 ± 3 vs. 23 ± 1 kg/m(2), p < 0.001) and lower self-reported activity levels by 47 % relative to normal weight asthmatics (p < 0.05). Obese asthmatics had a significantly lower maximal oxygen uptake (VO(2)) (82 ± 14 vs. 92 ± 10 %predicted) and work rate (75 ± 8 vs. 89 ± 13 %predicted) relative to normal weight asthmatics (p < 0.05). The anaerobic threshold occurred at a lower VO(2) in obese asthmatics vs. normal weight asthmatics (54 ± 15 vs. 66 ± 16 %predicted, p < 0.05). Ventilatory responses were superimposed throughout exercise with no evidence of a ventilatory limitation in either group. Cardiovascular responses were normal in both groups. Dyspnoea responses were similar but the obese asthmatics experienced greater leg fatigue ratings at submaximal work rates. In conclusion, obese individuals with well controlled asthma have reduced cardiorespiratory fitness and greater leg fatigue ratings relative to normal weight asthmatics. The relatively reduced cardiorespiratory fitness and exercise performance in obese compared to normal weight asthmatics is most likely driven by their more sedentary lifestyle and resultant deconditioning rather than due to respiratory factors.

Cardiorespiratory and sensory responses to exercise in well-controlled asthmatics.

OBJECTIVES: The purpose of this study was to evaluate detailed ventilatory, cardiovascular and sensory responses to cycle exercise in sedentary patients with well-controlled asthma and healthy controls. METHODS: Subjects included sedentary patients meeting criteria for well-controlled asthma (n = 14), and healthy age- and activity-matched controls (n = 14). Visit 1 included screening for eligibility, medical history, anthropometrics, physical activity assessment, and pre- and post-bronchodilator spirometry. Visit 2 included spirometry and a symptom limited incremental cycle exercise test. Detailed ventilatory, cardiovascular and sensory responses were measured at rest and throughout exercise. RESULTS: Asthmatics and controls were well matched for age, body mass index and physical activity levels. Baseline forced expiratory volume in 1 second (FEV(1)) was similar between asthmatics and controls (98 ± 10 versus 95 ± 9% predicted, respectively, p > 0.05). No significant differences were observed between asthmatics and controls for maximal oxygen uptake (31.8 ± 5.6 versus 30.6 ± 5.9 ml/kg/min, respectively, p > 0.05) and power output (134 ± 35 versus 144 ± 32 W, respectively, p > 0.05). Minute ventilation (V(E)) relative to maximum voluntary ventilation (V(E)/MVV) was similar between groups at maximal exercise with no subjects showing evidence of ventilatory limitation. Asthmatics and controls achieved similar age-predicted maximum heart rates (92 ± 7 versus 93 ± 8% predicted, respectively, p > 0.05). Ratings of perceived breathing discomfort and leg fatigue were not different between groups throughout exercise. CONCLUSIONS: The results of this study indicate that sedentary patients with well-controlled asthma have preserved sensory and cardiorespiratory responses to exercise with no evidence of exercise impairment or ventilatory limitation.

Responsiveness of continuous ratings of dyspnea during exercise in patients with COPD.

PURPOSE: To examine the responsiveness of a new computerized method for patients to provide continuous ratings of dyspnea during exercise in patients with chronic obstructive pulmonary disease (COPD). METHODS: In this randomized, double-blind study the effects of an inhaled bronchodilator (BD), albuterol/ipratropium bromide solution, were compared with normal saline (NS) in 30 patients with COPD (age, 66+/-9 yr; forced expiratory volume in 1 s, 48+/-14% pred). At visit 1, patients were familiarized with the cycle ergometer and computer, monitor, and mouse system to provide continuous ratings of dyspnea during exercise. At subsequent visits 2-3 d apart, patients performed pulmonary function tests followed by incremental ramp (15 W.min-1) and, 1 h later, constant work (at 55% of maximal work capacity) exercise tests. RESULTS: During incremental exercise the slopes of VO2:dyspnea and VE:dyspnea regressions were significantly lower, and patients exercised longer (Delta=0.4 min; P=0.003) with BD therapy compared with NS. During constant work exercise there was a significant reduction in dyspnea at the same exercise duration (5.0+/-2.8 vs 6.2+/-2.8 units on the 0-10 category-ratio scale; P=0.02) and patients exercised longer (Delta=0.9 min; P=0.04) with BD therapy. Changes in lung function at rest did not correlate significantly with changes in dyspnea ratings during exercise. CONCLUSIONS: Continuous ratings of dyspnea were responsive to inhaled bronchodilator therapy during both incremental and constant work exercise tests in patients with symptomatic COPD.

Development of self-administered versions of modified baseline and transition dyspnea indexes in COPD.

In this study we developed self-administered versions of modified baseline and transition dyspnea indexes and compared the scores obtained by this method with the mean value obtained by two trained interviewers. Twenty-five patients (14 males/11 females) with chronic obstructive disease who had a chief complaint of "breathlessness" were tested. Age was 66+/-11 years; forced expiratory volume in one second was 48+/-23% predicted. The baseline total scores were 5.0+/-1.8 for the interviewers and 5.4+/-2.0 for the self-administered method. For the baseline dyspnea scores the correlations were 0.83 (p<0.0001) between self-administration and the mean value of two interviewers and 0.75 (p<0.0001) between the two interviewers. The transition total scores, obtained an average of 102 days (range, 7-377 days) later, were - 0.1+/-3.0 for the interviewers and - 0.4+/-3.0 for the self-administered method. For the transition dyspnea scores the correlations were 0.94 (p<0.0001) between self-administration and the mean value of two interviewers and 0.83 (p<0.0001) between the two interviewers. The self-administered dyspnea scores had similar correlations with measures of lung function as did the interview dyspnea scores. We conclude that self-administered versions of the modified baseline and transition dyspnea indexes provide comparable scores as those obtained by trained and experienced interviewers. The advantages of the self-administered versions include standardized methodology and computerized scoring.

Effect of the combination of two bronchodilators on breathlessness in patients with chronic obstructive pulmonary disease. A crossover clinical trial.

BACKGROUND: Dyspnea is the major limiting symptom for patients with chronic obstructive pulmonary disease (COPD). This study was designed to investigate the impact of the combination of two bronchodilators on perception of dyspnea in these patients. METHODS: Twenty patients with moderate to severe COPD (age was [mean +/- standard deviation (SD)] 64 +/- 7 years, FEV1/FVC ratio was 45 +/- 11%) were randomized in a crossover, double-blind, placebo-controlled clinical trial to receive two puffs of either ipratropium bromide plus salbutamol (IB+S), IB+placebo (P), S+P, or P+P through metered dose inhalers (MDIs) daily over a 2-week period for each combination. At the end of each period, spirometry was obtained at baseline and 15, 30, 60, and 120 min after bronchodilator. Dyspnea was evaluated using a Borg scale during a 12-min walking test (12-MWT) performed at baseline and 120 min after MDIs use. In addition, the dyspnea component of the Chronic Respiratory Disease Questionnaire (CRDQ) and a diary of symptoms were used to evaluate this symptom. RESULTS: After 15 days of treatment, FEV1 improved significantly with all three combinations of MDIs containing bronchodilator agents. In comparison with placebo, significant improvement in dyspnea during 12-MWT was observed only when the combination of IB+S was used. No significant changes in CRDQ or patients' symptom diaries were observed with any combinations used. CONCLUSIONS: Combination of the two bronchodilators used in this study appears to alleviate perception of dyspnea more than use of either agent alone.

Stability of dyspnea ratings after exercise training in patients with COPD.

PURPOSE: The purpose of this study was to examine whether patients with chronic obstructive pulmonary disease (COPD) would report similar ratings of dyspnea at the same relative exercise intensity after participation in pulmonary rehabilitation. METHODS: Forty-two patients with COPD performed incremental cardiopulmonary exercise testing before and after completion of a 6-wk exercise-training program. Subjects rated dyspnea on the 0-10 category-ratio (CR-10) scale each minute of the exercise test. RESULTS: Both responders (21 patients who exhibited an increase in [OV0312]O(2peak) after pulmonary rehabilitation) and nonresponders (21 patients who had no increase in [OV0312]O(2peak)) reported slightly lower ratings of dyspnea ( approximately 0.5 on the CR-10 scale) at the same relative (50% and 75% of [OV0312]O(2peak)) exercise intensities. These changes in dyspnea ratings after pulmonary rehabilitation were not significantly different between responders and nonresponders. CONCLUSION: The study suggests that patients with COPD can use the same ratings of dyspnea to monitor training at the same relative exercise intensity whether they achieve a physiological training response or not.

Etiopatogénesis de la enfermedad pulmonar obstructiva crónica. Con énfasis en el enfisema pulmonar / Pathogenesis of chrinic obstructive pulmonary disease. with emphasis on pulmonary emphysema

La enfermedad pulmonar obstructiva crónica es un término cuyo espectro incluye a la bronquitis crónica, a la enfermedad de la vía aérea pequeña y al enfisema pulmonar. En este trabajo despúes de definir cada una de estas entidades, se abordó la etiopatogénesis de la enfermedad pulmonar obstructiva crónica como una entidad funcional única, sin considerar si la enfermedad de la vía aérea pequeña o el enfisema, contribuyen de manera independiente en mayor o menor grado a tal obstrucción. Aunque prácticamente, los mismo factores de riesgo están implicados en la patogénesis de las tres entidades, en este trabajo se discuten los probables mecanismos por los que esos diferentes factores pueden conducir a la limitación del flujo en la vía aérea. Finalmente, en relación al enfisema pulmonar, se revisa desde su origen, la teoría del desequilibrio proteasas-antiproteasas, como la hipótesis que en la actualidad es más aceptada para explicar la génesis de la destrucción pulmonar

Diseño de una clínica para el estudio de las enfermedades pulmonares obstructivas crónicas (EPOC) en el Instituto Nacional de Enfermedades Respiratorias / Desing of a clinical for the study of the chronic obstructive pulmonary diseases (COPD) at the National Institute of Respiratory Diseases

Presentamos en esta comunicación los fundamentos, el ideario, los objetivos y los propósitos de una clínica diseñada para la atención de los pacientes afectados por una enfermedad pulmonar obstructiva crónica (EPOC). La idea surgió de la observación del impacto económico del que estas enfermedades son responsables. Creemos que nuestro Instituto no es el único centro hospitalario con este problema. Por tanto, este diseño podría ser de utilidad, ya sea que se quiera abordar la enfermedad exclusivamente desde el punto de vista asistencial, o de investigación. A 6 meses de su creación, los hechos que se mencionan es todo lo que existe. Nuestra hipótesis predice que la atención de los enfermos con EPOC será más personalizada y mejor, y esto es el preludio a la atención de excelencia que se pretende. Además, vaticina que se podrán generar conocimientos de la enfermedad como consecuencia de la realización de investigaciones clínicas originales. El tiempo se erigirá en estadística de prueba para aceptar o rechazar nuestra hipótesis

Rehabilitación pulmonar del paciente con cirugía de tórax. Comparación de la aplicación pre y postquirúrgica versus solamente postquirúrgica / Pulmonary rehabilitation of the petient with chest surgery. comparison of pre-and post-surgical application versus post-surgical application only

En el presente trabajo se estudió a dos grupos de pacientes que fueron sometidos a cirugía de tórax por diversas causas, con un programa de ejercicios de rehabilitación pulmonar. El primero de ellos, formado por 28 pacientes, recibió el tratamiento antes y después de la cirugía; el segundo grupo, integrado por 51 pacientes, sólo recibió tratamiento con el mismo programa de ejercicios después de la cirugía. El tratamiento consistió en técnicas de relajación, ejercicios respiratorios, como respiración diafragmáica, costobasal, respiración sumada, drenaje postural, vibración manual, entrenamiento de tos y ejercicios de higiene de columna. Los resultados muestran que el grupo que recibió el tratamiento antes y después de la cirugía presentó una menor morbilidad en términos de complicaciones pulmonares relacionados con la cirugía, que el grupo que sñolo recibió el tratamiento después de la cirugía. El grupo tratamiento pre y postquirúrgico mostró, además, un menor número de días de estancia hospitalaria, que podría traducirse en una recuperación más rápida y con menor costo. Con base en estos resultados, se recomienda el uso de un curso de tratamiento previo a la cirugía, como el programa de rehabilitación mencionando en el presente estudio, para optimizar la atención de los pacientes que sean candidatos a un procedimiento queirúrgico de tórax, y reducir así la posibilidad de complicaciones en el postoperatorio

Reproducibilidad de una prueba de inteligencia en pacientes con insuficiencia respiratoria crónica / Reproducibility of an inteligence test in patients with chronic respiratory failure

En 10 pacientes con insuficiencia respiratoria crónica, se probó la reproducibilidad de la escala de inteligencia para adultos de Welchsler (WAIS). La prueba se aplicó en dos ocasiones diferentes por el mismo investigador con intervalo de un mes. A todos los pacientes se les realizó espirometría, gasometría arterial en reposo y oximetría digital. Para medir la concordancia entre la primera y la segunda aplicación, se utilizó el coeficiente de correlación intraclase (RI). Adicionalmente se probó la significancia estadística de los cambios observados con la prueba de t de Student para muestras pareadas. Todos los pacientes mostraron disminución de la capacidad vital forzada, hipoxemia y desaturación de oxígeno en reposo de grado variable. La mayor parte de las subáreas del WAIS, así como los coeficientes de inteligencia verbal, de ejecución y total, mostraron una concordancia > 0.70. Las subáreas de ordenación de dibujos, composición de objetos y vocabulario, así como el índice del deterioro mental mostraron concordancias muy bajas. Sin embargo, la diferencia promedio entre la primera y la segunda aplicación sólo fue significativa para la subárea de composición de objetos (p < 0.01). Estos resultados sugieren que después de un mes, el WAIS es una prueba que tiene una concordancia aceptable en la mayoría de las subáreas, por tanto, podría ser utilizado en mediciones secuenciales en pacientes con insuficiencia respiratoria cuando se quieren detectar cambios en sus habilidades intelectuales

Alteraciones cardiopulmonares en la xifoescoliosis / Cardiopulmonary alterations in xiphoscoliosis

La falla respiratoria crónica y la hipertensión pulmonar, son las complicaciones más frecuentes en pacientes con xifoescoliosis severa con ángulos mayores de 100 grados. La capacidad vital (CV), la capacidad funcional total (CFT), la distensibilidad del sistema respiratorio (CL,dyn Dpd), la distensibilidad de la caja torácica(cl, st Dpd), la presión arterial de oxígeno(PaO2)y el volumen espiratorio forzado en el primer segundo(VEF1), son inversamente proporcionales al ángulo de la escoliosis y a la edad del paciente. Asimismo, la presión arterial de dióxido de carbono (PCO2) es directamente proporcional al ángulo de la escoliosis. La hiperplasia de la íntima y la hipertrofia de la media como parte de los cambios a nivel cardiovascular, incrementan las resistencias vasculares, disminuyen la distensibilidad pulmonar y son la causa de hipertensión pulmonar, con pulmonale y falla cardiaca congestiva. Las manifestaciones clínicas ocurrirán dependiendo del grado de severidad de la escoliosis