ESTIMATION OF THE RESIDUAL VOLUME OF THE LUNGS BY NITROGEN WASHOUT TECHNIQUE.
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BACKGROUND: Exercise is an important component of pulmonary rehabilitation for patients with chronic lung disease. OBJECTIVE: To explore the role of physical activity in maintaining cardiac and respiratory function in healthy people. METHODS: Cardiorespiratory fitness was measured by a maximal treadmill test (MTT), and respiratory function was tested by spirometry. The cross sectional study included data from 24 536 healthy persons who were examined at the Cooper Clinic between 1971 and 1995; the longitudinal study included data from 5707 healthy persons who had an initial visit between 1971 and 1995 and a subsequent visit during the next five years. All participants were aged 25-55 years and completed a cardiorespiratory test and a medical questionnaire. RESULTS: In the cross sectional study, after controlling for covariates, being active and not being a recent smoker were associated with better cardiorespiratory fitness and respiratory function in both men and women. In the follow up study, persons who remained or became active had better MTT than persons who remained or became sedentary. Men who remained active had higher forced expiratory volume in one second (FEV(1)) and forced vital capacity (FVC) than the other groups. Smoking was related to lower cardiorespiratory fitness and respiratory function. CONCLUSIONS: Physical activity and non-smoking or smoking cessation is associated with maintenance of cardiorespiratory fitness. Change in physical activity habits is associated with change in cardiorespiratory fitness, but respiratory function contributed little to this association during a five year follow up.
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BACKGROUND: Cystic fibrosis is the most frequent congenital disease in Caucasian and is transmitted by recessive autosomic inheritance. It is characterized by affection of different glands of exocrine secretion, particularly the pancreas and the lung. The aim of this study was to analyze the degree of alteration of pulmonary and pancreatic exocrine function in a group of patients with cystic fibrosis in relation to the time of disease evolution. METHODS: Twenty-one patients between 9 and 31 years of age were studied; 11 with an evolution of lower than or equal to 158 months and 10 with an evolution of higher than 158 months (median of the total patients). To study pancreatic exocrine function the BT-PABA test immunoreactive serum trypsin test were used. To evaluate respiratory function FEV1, FVC, FEV1/FVC ratio and PaO2 were used. RESULTS: The results obtained demonstrated that in the group with a lower time of evolution the diagnosis had been carried out at earlier ages (17 +/- 17 months versus 84 +/- 60 months; p = 0.002) and presented a significantly more altered pancreatic exocrine function (BT-PABA: 13 +/- 12% versus 35 +/- 23%; p = 0.013). However, respiratory function was altered in the group with longer time of evolution (FEV1: 68 +/- 20% versus 36 +/- 23%; p = 0.003; FVC: 74 +/- 9 versus 52 +/- 25%; p = 0.013; FEV1/FEV: 77 +/- 19 versus 50 +/- 9%; p < 0.001; PaO2: 84 +/- 16 versus 58 +/- 11%; p < 0.001). CONCLUSIONS: Pancreatic exocrine function is most intensely affected in patients diagnosed with cystic fibrosis at earlier and with shorter times of evolution while patients who have the longest time of evolution and who were diagnosed later in life presented greater changes in respiratory function.
Respiratory muscle strength and endurance should be assessed when dyspnea, respiratory failure, or poor performance on routine pulmonary function tests are unexplained. Respiratory muscle strength can be measured non-invasively from maximal mouth pressures, but measurement of transdiaphragmatic pressure refines the assessment. The maximal voluntary ventilation test is the only simple index of ventilatory or respiratory muscle endurance. Other tests for endurance and fatigue are more difficult, but some newer techniques may be applicable to the clinical laboratory. Some patients who exhibit tachypnea, marked use of neck inspiratory muscles, and chest-abdomen asynchrony may be developing respiratory muscle fatigue.
Exercise intolerance is a common complaint, the cause of which often remains elusive after a comprehensive evaluation. In this report, we describe 28 patients with unexplained dyspnea or exertional limitation secondary to biopsy-proven mitochondrial myopathies. Patients were prospectively identified from a multidisciplinary dyspnea clinic at a tertiary referral center. All patients were without underlying pulmonary, cardiac, or other neuromuscular disorders. Patients underwent history, physical examination, complete pulmonary function testing, respiratory muscle testing, cardiopulmonary exercise testing, and muscle biopsy. Results were compared with a group of normal control subjects. The estimated period prevalence was 8.5% (28 of 331). Spirometry, lung volumes, and gas exchange were normal in patients and control subjects. Compared with control subjects, the patient group demonstrated decreased exercise capacity (maximum achieved V O(2) 67 versus 104% predicted; p < 0.0001) and respiratory muscle weakness (PI(max) 77 versus 115% predicted; p = 0.001). These patients have a characteristic exercise response that was hyperventilatory (peak VE/V CO(2); 55 versus 42) and hypercirculatory (maximum heart rate - baseline heart rate/V O(2)max - baseline V O(2)max; 91 versus 41) compared to control subjects. Patients stopping exercise due to dyspnea (n = 16) (as compared with muscle fatigue, n = 11) displayed weaker respiratory muscles (Pdi(max) 61 versus 115 cm H(2)O; p = 0.01) and were more likely to reach mechanical ventilatory limitation (V Emax/ MVV 0.81 versus 0.58; p = 0.02). The sensation of dyspnea was related to indices of respiratory muscle function including respiratory rate and inspiratory flow. We conclude that mitochondrial myopathies are more prevalent than previously reported. The characteristic physiological profile may be useful in the diagnostic evaluation of mitochondrial myopathy.
Since the postoperative long-term evaluation for thoracic esophageal carcinoma had not been sufficient by a conventional respiratory function test alone, investigation was carried out by observing the changes in motor tolerance. The subjects were selected of 50 cases who elapsed more than 3 months before and after the operation among the cases who had been undergone radical operations with right thoracotomy and laparotomy for thoracic esophageal carcinoma; and then all of the subjects were subjected to a conventional respiratory function test and a respiratory movement loading test. Furthermore, investigation by use of multivariate analysis (Quantification: Class 1) was conducted for the factors relating to the depression of respiratory movement. For loading the movement, bicycle-type ergometer were employed, and a graded gradual-increase loading method was adopted. With the general respiratory function test, vital capacity was depressed from a preoperative average value of 2.1 +/- 0.4 (1/m2) to a postoperative average value of 1.6 +/- 0.3 (1/m2) showing a depressing trend being significant to a postoperative condition (p < 0.0001), and no significant postoperative difference was observed for FEV 1.0%. Even in such a condition, no significant depression was observed for oxygen intake at resting, but the maximum oxygen intake showed a significant depression (p < 0.0001) from a preoperative average value of 22.3 +/- 5.0 to a postoperative average value of 19.3 +/- 4.1 ml/min/kg. The maximum carbon oxide evacuation showed a significant depression (p < 0.0001) after operation. The ventilation quantity in a course of movement showed a depressing trend after operation, with be number of respiration in an increasing trend, showing a shallow-but-quick respiratory pattern. Mobility restriction due to circulation factors was not observed, and also the nutrition before and after operation did not show any significant difference in the blood examination. But the lactic acid during movement showed a significant increase after operation. As described above, it is considered that a pattern of restrictive impairment at resting increased an oxygen equivalent resulted from depression of oxygen intake by the movement, an increase in dead space ventilation rate for minute ventilation at movement, and a shallow-but-quick respiratory pattern have caused aggravation of the ventilation efficiency, which finally led to the interruption of movement. In a long-term period, as clinical factors relating to those, cigarette smoking, nutrition before operation, age, and postoperative radiation therapy are concerned, which were thus considered the key factors in considering the postoperative long-term QOL. Nutrition and rehabilitation by continuous muscle training is necessary to improve the long-term QOL, after radical esophagectomy.
Survival rates for infants undergoing surgical repair of oesophageal atresia with tracheo-oesophageal fistula (OA-TOF) have improved dramatically, but this condition remains associated with substantial morbidity. Most studies of patients following OA-TOF repair have concentrated on school-age and older people; whereas, the most hazardous period is infancy. We aimed to assess respiratory function in a group of infants following primary operative repair, and to relate the results to clinical findings during the first year of life. We studied 16 infants within 3 months of primary repair of OA-TOF. Measurements were made of maximum expiratory flow at functional residual capacity (VmaxFRC), thoracic gas volume (TGV) and airways resistance (Raw). Ten infants had tests repeated, usually to assess progress alongside continuing symptoms, or to ascertain improvement following additional surgery. Seven infants had essentially normal initial respiratory function tests, and six remained either symptom-free or developed only minor clinical problems. One infant subsequently developed stridor, with spontaneous improvement towards the end of the first year. The remaining nine infants had abnormal initial respiratory function tests: one was symptom-free at that time. The remainder developed respiratory and/or gastro-oesophageal symptoms. The functional abnormalities appeared to reflect the severity of the clinical problems encountered. We conclude that respiratory function testing in infants following OA-TOF repair may augment the value of clinical appraisal, help define postoperative respiratory status, and provide a general guide to likely clinical progress.
The measurement of respiratory resistance by forced oscillations, a theory known for over 20 years, has found a practical application by a simplification of the method. The comparison with the plethysmographic measurement of the resistance of airways in 27 healthy children shows a good correlation (r = 0,73), similarly with F.E.V1 (r = 0,78) and peak flow (r = 0,61). This technique does not require the forced expiration demanded by the measurement of F.E.V1 and peak flow and it does not need the costly equipment of body plethysmography. In this technique the causes of error are easy to detect. Its rapid execution and the absence of discomfort should make it a choice method in the functional respiratory tests in the child.
INTRODUCTION: For possible use as a predictor of wheezing illnesses in routine care, we evaluated the feasibility and variability of measurement of passive respiratory mechanics in a large, open population of healthy neonates and infants. METHODS: As part of the ongoing Wheezing Illnesses Study Leidsche Rijn, respiratory compliance (Crs), respiratory resistance (Rrs), and time constant (taurs) were measured during natural sleep in 450 healthy term neonates and infants using the single-occlusion technique (SOT). Interobserver and intraobserver variability of data sampling and the subsequent selection and analysis of occlusions as well as intra-measurement variability were examined. RESULTS: Technically acceptable lung function measurements could be performed in 328 infants (73%). Low intraobserver and interobserver variability was found for both data sampling (intraclass correlation coefficient [ICC] > or = 0.87) and for selection and analysis of occlusions (ICC > or = 0.99). Intra-measurement variability was low, with a mean intra-measurement coefficients of variation for Crs, Rrs, and taurs of 8.5%, 10.4%, and 15.4%, respectively. Averaging three or more occlusions resulted in stable values of Crs, Rrs, and taurs. CONCLUSION: Results of this study indicate that feasibility and variability of lung function testing using the SOT is acceptable for use in large populations of healthy neonates and infants in routine care.