RESUMEN
A 23-year-old woman and a 13-year-old boy were diagnosed with mitochondrial respiratory chain disease. The woman had muscle pain, fatigue and bilateral ophthalmoplegia--symptoms consistent with Kearns-Sayre syndrome. The boy had aspecific symptoms; eventually, reduced activity of complex 1 was found to be the cause of the mitochondrial respiratory chain disease in the boy and his mother, who had suffered from unexplained fatigue and muscle pain for 15 years. Mitochondrial diseases often involve several organ systems. Diagnosis can be difficult, because laboratory tests such as serum and urinary lactate and creatine kinase have low sensitivity and specificity. Biochemical assessment of muscle biopsy can reveal reduced oxidation ATP synthesis and sometimes specific abnormalities in individual protein complexes. DNA analysis may be helpful in demonstrating mitochondrial or nuclear mutations or deletions. The goal of treatment is to increase mitochondrial ATP production, improve clinical symptoms and enhance stamina. Replacement of the following substances (also referred to as cofactors) may be attempted: co-enzyme Q10, antioxidants (lipoic acid, vitamins C and E), riboflavin, thiamine, creatine and carnitine. Evidence regarding the optimal treatment approach is lacking; one usually has to rely on observing effects in the individual patient.
Asunto(s)
ADN Mitocondrial/metabolismo , Complejo IV de Transporte de Electrones/metabolismo , Enfermedades Mitocondriales/diagnóstico , Adolescente , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Enfermedades Mitocondriales/patología , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Adulto JovenRESUMEN
BACKGROUND: After lung transplantation (LTx) exercise capacity frequently remains limited, despite significantly improved pulmonary function. The aim of this study was to evaluate maximal exercise capacity and peripheral muscle force before and 1 year after LTx, and to determine whether peripheral muscle force and lactate threshold (LT) limit exercise capacity 1 year after LTx. METHODS: Twenty-five subjects (mean age 43 years, 8 women and 17 men, 4 single-lung transplantations) were included in the study. Measurements included maximal exercise capacity, lactate threshold (symptom-limited bicycle ergometer test) and muscle force test (hand-held dynamometer) were performed before and 1 year after LTx. RESULTS: Before LTx, all patients showed severe exercise intolerance (mean +/- SD): work capacity (W(peak)), 11.6 +/- 18 W; peak oxygen uptake (Vo(2)), 8.6 +/- 3.6 ml/min/kg. After LTx, exercise capacity improved significantly: W(peak), 69 +/- 27 W (p < 0.001); peak Vo(2), 15.7 +/- 4.3 ml/min/kg (p < 0.001). Ventilatory factors did not appear to limit exercise capacity. Quadriceps muscle force pre- vs post-LTx was: 248 +/- 73 N vs 281 +/- 68 N (p < 0.05). Post-LTx, a significant correlation was found between LT and exercise capacity (r = 0.76, p < 0.001), between muscle force and exercise capacity (r = 0.41, p < 0.05) and between the LT and muscle force (r = 0.53, p < 0.01). CONCLUSIONS: The occurrence of an early and pathologic LT and peripheral muscle weakness contributes to the limitation of exercise capacity and reflects a peripheral deficit post-LTx.
Asunto(s)
Tolerancia al Ejercicio/fisiología , Ejercicio Físico/fisiología , Trasplante de Pulmón/fisiología , Debilidad Muscular/fisiopatología , Adolescente , Adulto , Estudios de Cohortes , Prueba de Esfuerzo , Femenino , Humanos , Lactatos/metabolismo , Pulmón/fisiología , Masculino , Persona de Mediana Edad , Dinamómetro de Fuerza Muscular , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiología , Consumo de Oxígeno/fisiologíaRESUMEN
The aim of this study was to investigate whether the increase of ammonia concentration and lactate concentration in blood was accompanied by an increased expiration of ammonia during graded exercise. Eleven healthy subjects performed an incremental cycle ergometer test. Blood ammonia, blood lactate and the amount of expired ammonia were measured until 30 minutes post exercise. The expired air was guided through a flow chamber filled with a sulphuric acid solution to trap the expired ammonia. Blood ammonia, blood lactate increased more than proportionally and the amount of expired ammonia (in micromol/min) increased exponentially with the workload. Post-exercise the amount of expired ammonia decreased within a few minutes back to pre-exercise levels while the concentrations of lactate and ammonia in blood decreased much more slowly and were still elevated after 30 minutes of recovery. We conclude that the more than proportional increase of ammonia and lactate during graded exercise, is accompanied with an exponential increase of expired ammonia output. Faster and more accurate ammonia gas detection techniques are necessary to quantify more precisely the respiratory ammonia output during graded exercise.
Asunto(s)
Amoníaco/metabolismo , Ejercicio Físico/fisiología , Respiración , Adulto , Amoníaco/sangre , Pruebas Respiratorias , Colorimetría , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Estudios Prospectivos , Intercambio Gaseoso PulmonarRESUMEN
The majority of patients with cystic fibrosis (CF) will grow into adulthood. Despite this improvement in survival, the disease is progressive, especially with respect to the decline in pulmonary function, which in turn may have an impact on a patient's quality of life. In this study we evaluated the quality of life in CF adults and examined the relationship between quality of life and pulmonary function, exercise capacity, and dyspnea. We assessed in 15 patients in stable clinical condition their forced expired volume in the first second (FEV1) inspiratory vital capacity (IVC), cycle exercise capacity (Wmax), and subjective degrees of dyspnea during daily living (MRC dyspnea scale). Quality of life was assessed with the Sickness Impact Profile (SIP). A sample of 100 healthy individuals, ranging in age from 18 to 30 years, served as the control group. Mean (SD) age of the patients was 25.9 (7.3) years, FEV1 was 38 (16)% predicted, IVC was 65 (17)% predicted, FEV1 IVC ratio was 46 (10)%, and Wmax was 90 (54) W. The overall SIP and physical SIP scores in CF patients were significantly higher than in the controls, indicating more impairment in overall and physical functioning in the patients than in the control group (P < 0.001). The psychosocial SIP score did not differ significantly between the two groups. Overall SIP score correlated poorly with FEV1 % predicted (r = -0.33; n.s) and IVC % predicted (r = -0.36; n.s.) but showed a better and significant relationship to the maximal exercise capacity (r = -0.57; P < 0.05). MRC dyspnea scores showed a strong correlation with overall SIP scores (r = 0.75; P < 0.001). These results show that CF affects quality of life in adults primarily due to a limitation in physical functioning. Psychosocial functioning did not differ from that of healthy controls. Exercise capacity and dyspnea scores were related to the impairment in the quality of life. Therefore, the effects of programs aimed to improve exercise capacity and reduce dyspnea on CF patients' quality of life need to be evaluated.
Asunto(s)
Fibrosis Quística/fisiopatología , Calidad de Vida , Mecánica Respiratoria , Adolescente , Adulto , Disnea/etiología , Ejercicio Físico , Femenino , Volumen Espiratorio Forzado , Humanos , Masculino , Perfil de Impacto de EnfermedadRESUMEN
The median age of survival in patients with cystic fibrosis (CF) has improved considerably. Despite this improvement, deterioration of pulmonary function and decrease in exercise capacity are still the main problems for many patients. Although dyspnoea is a common complaint in CF patients, relatively little regard has been paid to this symptom. This study examined the relationship between dyspnoea, bicycle exercise capacity and pulmonary function in patients with CF. In 14 patients in a stable clinical condition, pulmonary function [forced expiratory volume in 1 s (FEV1), inspiratory vital capacity (IVC)], bicycle exercise capacity [maximum exercise capacity (Wmax)], subjective degree of dyspnoea during daily living [Medical Research Council (MRC) dyspnoea scale], and during exercise (Borg scale) were assessed. The mean (SD) age of the patients was 25 (6.8) years, FEV1 was 41 (19)% predicted, IVC was 63 (17)% predicted and FEV1/IVC ratio was 47 (10)%; median (range) Wmax was 55 (0-79)% predicted. Bicycle exercise test performance appeared to be mainly determined by pulmonary function and MRC dyspnoea grade; multiple regression equation containing FEV1 and dyspnoea accounted for 76% of the variance in Wmax (% predicted) (Wmax = -7.9 dysp + 1.1 FEV1, +24). Exercise dyspnoea, assessed by the Borg scale, showed a significant linear correlation with minute ventilation. (VE), maximal voluntary ventilation (MVV) (%) (r = 0.76; P < 0.001). Medical Research Council dyspnoea score correlated relatively poorly with FEV1 (% predicted) (r = -0.17; n.s.) and IVC (% predicted) (r = -0.48; n.s.). Borg score at maximal exercise did not correlate with MRC dyspnoea score (r = -0.07). Borg50% score correlated significantly with MRC dyspnoea score (r = 0.61; P < 0.05). These results show that dyspnoea has an influence on exercise capacity. Dyspnoea score showed a large inter-individual variation, not strongly related to pulmonary function. It is concluded that dyspnoea deserves more attention in CF patients and needs to be assessed in rehabilitation programmes and other intervention studies in these patients.
Asunto(s)
Fibrosis Quística/fisiopatología , Disnea/fisiopatología , Adolescente , Adulto , Prueba de Esfuerzo , Femenino , Volumen Espiratorio Forzado , Humanos , Capacidad Inspiratoria , Masculino , Ventilación Pulmonar , Análisis de Regresión , Índice de Severidad de la EnfermedadRESUMEN
In November 1990, a lung transplantation program began at the University Hospital in Groningen, the Netherlands. As of April 1994, 300 patients were referred for lung transplantation and we investigated the decisions that have been made concerning these referrals up to January 1, 1995. The patients were evaluated according to a stepwise procedure. In stage 1, written information about the referred patients was discussed during the weekly, multidisciplinary lung transplantation meeting. In this stage, 14% of the patients were rejected and 2% were postponed. If no major objections for transplantation were identified, the patient was invited for a visit to the outpatient clinic, stage 2. The newly acquired information from that visit was discussed again at the transplantation meeting. In this stage, 11% of the patients were rejected and 18% postponed. The remaining patients underwent an (partial or complete) inpatient evaluation, stage 3. From all patients about whom a decision was made in this stage, only 5% were rejected, respectively 35% after partial evaluation and only 1.5% after complete evaluation. A total of 110 patients (37% of all referred patients) were listed for lung transplantation, stage 4. Of the listed patients, 20% died while awaiting an appropriate donor. The group of patients with COPD/emphysema had by far the lowest death rate on the waiting list. Patients with short stature (< or = 1.65 m) had a much higher risk to die on the waiting list compared with patients with longer stature, 42% vs 13%. As of January 1, 1995, 55 patients have undergone transplantation, which is 50% of all patients on the waiting list and 18% of all referred patients. The stepwise selection procedure identifies patients with potential contraindications at an early stage. In this way, unrealistic expectations and unnecessary examinations, expense, and/or hospital admissions may be prevented. Donor shortage, and thus waiting list problems, still remains a significant drawback in the further development of lung transplantation.
Asunto(s)
Enfermedades Pulmonares/cirugía , Trasplante de Pulmón , Selección de Paciente , Algoritmos , Contraindicaciones , Humanos , Países Bajos , Evaluación de Programas y Proyectos de Salud , Listas de EsperaRESUMEN
Atresia of the pulmonary veins of the left lung and the right upper lobe with moderate pulmonary hypertension was diagnosed in a 20 year old man presenting with exertional dyspnoea and haemoptysis. After left pneumonectomy gas exchange appeared to have improved. This was shown by improved arterial oxygen pressures during all steps of exercise in a cycle ergometer test in comparison with values obtained before surgery. This improvement could be entirely attributed to a decrease in physiological dead space ventilation.
Asunto(s)
Neumonectomía , Intercambio Gaseoso Pulmonar/fisiología , Venas Pulmonares/anomalías , Adulto , Prueba de Esfuerzo , Humanos , Masculino , Oxígeno/sangre , Periodo PosoperatorioRESUMEN
OBJECTIVE: To analyse the selection and outcome in patients placed on the waiting list for lung transplantation in Groningen. DESIGN: Retrospective and descriptive. SETTING: University Hospital Groningen. PATIENTS: Clinical lung transplantations have been performed at Groningen University Hospital since November 1990. Until the beginning of August 1993 over 200 patients were presented. Patients' eligibility for lung transplantation was evaluated according to a fixed protocol. RESULTS: Seventy patients were placed on the waiting list. Indications for lung transplantation were cystic fibrosis (22 patients), COPD/emphysema (24), pulmonary hypertension (14), pulmonary fibrosis (7), and another diagnosis (2). One patient required a second transplantation. Thirty patients underwent a transplantation after an average waiting period of 6.3 months. Eleven patients died on the waiting list, after an average waiting period of 3.9 months. The highest mortality on the waiting list concerned patients with cystic fibrosis. Characteristics and evolution on the waiting list of the selected patients were in accordance with the literature. CONCLUSION: The growing number of candidates for lung transplantation is increasing the shortage of suitable donor lungs. A successful lung transplantation programme necessitates expansion of the donor potential, as well as meticulous selection of candidates.
Asunto(s)
Trasplante de Pulmón , Listas de Espera , Adolescente , Adulto , Protocolos Clínicos , Fibrosis Quística/cirugía , Femenino , Humanos , Hipertensión Pulmonar/cirugía , Enfermedades Pulmonares Obstructivas/cirugía , Masculino , Persona de Mediana Edad , Países Bajos , Evaluación de Resultado en la Atención de Salud , Pronóstico , Fibrosis Pulmonar/cirugía , Pruebas de Función Respiratoria , Estudios RetrospectivosRESUMEN
Physical training in patients with pulmonary diseases, including cystic fibrosis (CF), may improve exercise tolerance in these patients. Most training programs are performed in a clinical setting. Little information is available concerning the effect of home exercise training programs in CF patients. The purpose of this study was to investigate the effect of a home exercise training program in CF patients. Ten adolescent patients (seven male and three female) with CF, mean (SD) age 20.6 (6.5) years, participated in a home exercise training program for 3 months. Pretraining condition was assessed during a control period of 2 months in which patients were asked to continue their normal daily activities. Home exercise training consisted of cycle training of 15 min at a submaximal workload once a day and was supervised by a physiotherapist two times a week. A follow-up period of 1 month, in which the patients were advised to continue cycling at home without supervision, was included after the training program. Pulmonary function, bicycle exercise test performance, and the degree of limitation in activities of daily living (ADL) were measured. No significant differences were found between the two pretraining assessments. After the training period we found significant improvement in maximal exercise capacity (Wmax) (mean [SEM]: 126 [10] W before and 146 [11] W after; p = 0.004), maximal oxygen uptake (VO2max) (mean [SEM]: 31.4 [2.1] ml.kg-1.min-1 before and 36.5 [2.5] ml.kg-1.min-1 after; p = 0.008), oxygen pulse (VO2/HR) (mean [SEM]: 10.9 [0.66] ml before and 11.9 [0.74] ml after; p = 0.047), and degree of limitation in ADL (mean [SEM]: 2.4 [0.43] before and 1.5 [0.48] after; p = 0.019) as compared with the initial values. Since no significant differences were found between the posttraining values and the results at the end of the follow-up period, the patients were apparently able to maintain the training effects during the follow-up period. We conclude that in CF patients, a home exercise training program, after clinical assessment of exercise tolerance, is an effective and relatively simple treatment to improve physical performance and decrease limitation in ADL and should be included in the maintenance treatment in these patients.
Asunto(s)
Ciclismo/fisiología , Fibrosis Quística/rehabilitación , Terapia por Ejercicio , Actividades Cotidianas , Adolescente , Adulto , Umbral Anaerobio/fisiología , Fibrosis Quística/fisiopatología , Tolerancia al Ejercicio/fisiología , Femenino , Estudios de Seguimiento , Volumen Espiratorio Forzado/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Inhalación/fisiología , Masculino , Ventilación Voluntaria Máxima/fisiología , Consumo de Oxígeno/fisiología , Aptitud Física/fisiología , Respiración/fisiología , Espacio Muerto Respiratorio/fisiología , Capacidad Vital/fisiologíaRESUMEN
The effects of 100 mg ibopamine, an orally active aselective dopamine (DA) agonist, on plasma catecholamines was evaluated in 8 healthy men during sympathetic stimulation by graded exercise in a single-blind, placebo-controlled cross-over study. The exercise consisted of progressive cycling activity less than or equal to 90% of the previously determined VO2max. Graded exercise resulted in an increase in systolic and mean blood pressure (SBP, MBP), heart rate, norepinephrine (NE) and epinephrine level, with a decrease in diastolic BP (DBP). The increase in NE was significantly blunted by ibopamine as compared with placebo. No differences for BP, heart rate (HR), or epinephrine between placebo- and ibopamine study day were noted. In previous studies, ibopamine decreased resting plasma NE in patients with congestive heart failure (CHF), whereas plasma NE was not altered by ibopamine in healthy volunteers. This different outcome in both categories might therefore be explained by the absence of substantial sympathetic stimulation in normal humans at rest. Because it is reasonable to assume that the effect of ibopamine on systemic and local hemodynamics is negligible as compared with the effect of exercise in the healthy volunteers, the plasma decrease caused by ibopamine is probably related to stimulation of DA2-receptors. In conclusion, ibopamine blunts the increase of plasma NE during graded exercise in healthy men.
Asunto(s)
Desoxiepinefrina/análogos & derivados , Dopaminérgicos/farmacología , Ejercicio Físico/fisiología , Norepinefrina/sangre , Adulto , Glucemia/metabolismo , Presión Sanguínea/efectos de los fármacos , Desoxiepinefrina/sangre , Desoxiepinefrina/metabolismo , Desoxiepinefrina/farmacología , Dopaminérgicos/efectos adversos , Esquema de Medicación , Epinefrina/sangre , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Método Simple CiegoRESUMEN
The mean airway pressure difference within a respiratory cycle at end-inspiration was measured at different tidal volumes (VT) in 59 patients treated with mechanical ventilation, and plotted in a pressure-volume (P-V) diagram. Regression analysis revealed three types of regression lines which were clearly correlated with clinical pulmonary condition and outcome. The slope of such regression lines may be a more realistic representation of lung elasticity than conventional total static compliance, which is measured at only one VT, and the intercept of these lines may be a more appropriate reflection of operating lung volume than functional residual capacity. Ventilator settings should put the patient's lungs on the steepest part of the P-V curve with the smallest intercept, while maintaining acceptable arterial blood gas tensions.