Browsing by Author "CRUZ, E"

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    INSPIRATORY MUSCLE TRAINING IN CHRONIC AIR-FLOW LIMITATION - COMPARISON OF 2 DIFFERENT TRAINING LOADS WITH A THRESHOLD DEVICE
    (1994) LISBOA, C; MUNOZ, V; BEROIZA, T; LEIVA, A; CRUZ, E
    The usefulness of inspiratory muscle training (IMT) in chronic airflow limitation (CAL) patients is a controversial issue, mainly due to differences in the training load. To further evaluate this aspect, we studied the effect of the magnitude of the load using a threshold pressure trainer.
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    MEASUREMENT OF PLEURAL FLUID CHOLESTEROL AND LACTATE-DEHYDROGENASE - A SIMPLE AND ACCURATE SET OF INDICATORS FOR SEPARATING EXUDATES FROM TRANSUDATES
    (1995) COSTA, M; QUIROGA, T; CRUZ, E
    Objectives: To evaluate the usefulness of diverse combinations of pleural cholesterol concentration, pleural or serum protein, and lactate dehydrogenase (LDH) levels for the differentiation of pleural exudates and transudates.
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    STRONG-MOTION ACCELEROGRAPH ARRAY IN SANTIAGO, CHILE, AND PRELIMINARY EVALUATION OF SITE EFFECTS
    (JOHN WILEY & SONS LTD, 1991) MIDORIKAWA, S; RIDDELL, R; CRUZ, E
    A strong-motion accelerograph array in Santiago, Chile has been installed. One of the sites is located on rock and the other six sites are on soil ground with different surface geology, so that local site effects on ground motions can be studied. As a preliminary evaluation of the site effects, the spectral ratios of weak-motion records at soil sites with respect to the rock site are calculated. The spectral ratios show that the amplification of ground motions with respect to the rock site is approximately 1.25 on dense gravel deposits, 2.5 on stiff pumice ground and 3.5 on soft silt ground.
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    VENTILATORY DRIVE AND RESPIRATORY MUSCLE FUNCTION IN PREGNANCY
    (AMER LUNG ASSOC, 1991) CONTRERAS, G; GUTIERREZ, M; BEROIZA, T; FANTIN, A; ODDO, H; VILLARROEL, L; CRUZ, E; LISBOA, C
    It has been demonstrated that during pregnancy expiratory reserve volume (ERV) decreases and minute ventilation (VE) increases initially and then stabilizes. In order to determine the role of thoracoabdominal mechanics, control of breathing, and inspiratory muscle function in these alterations, we studied inspiratory pressures, lung volumes, thoracic configuration, and respiratory drive in 18 normal pregnant women at Weeks 13, 21, 30, and 37 of pregnancy. Ten of them were studied 6 months after delivery. Transdiaphragmatic pressure (Pdi) was measured at Week 37 and 3 months after delivery in an additional group of seven women. VE as well as VT/Tl increased early during gestation and remained unchanged thereafter. In contrast, mouth occlusion pressure (P0.1) increased progressively during pregnancy, from 1.53 +/- 0.16 (mean +/- SE) to 2.02 +/- 0.18 cm H2O, and fell significantly to 1.1 +/- 0.15 cm H2O after delivery, indicating that effective respiratory impedance increases during pregnancy. Mean P0.1 correlated with progesterone plasma levels (r = 0.918 p < 0.05). No changes in Plmax, PEmax, and Pdi(max), were observed. End-expiratory gastric pressure (Pga) increases significantly during pregnancy: 11.8 +/- 0.8 versus 8.4 +/- 1.12 cm H2O after delivery (p < 0.012). This increment was correlated with the fall in ERV observed in late pregnancy (r = 0.74 p < 0.05). Our results demonstrate that during pregnancy ventilatory drive and respiratory impedance increase with the consequent stabilization of VE, but our data do not permit us to differentiate whether the increment in P0.1 is secondary to the increase in impedance or to the rise in progesterone. Respiratory muscle function remains normal despite the alteration of thoracic configuration.
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    WEEKLY CUIRASS VENTILATION IMPROVES BLOOD-GASES AND INSPIRATORY MUSCLE STRENGTH IN PATIENTS WITH CHRONIC AIR-FLOW LIMITATION AND HYPERCARBIA
    (1988) GUTIERREZ, M; BEROIZA, T; CONTRERAS, G; DIAZ, O; CRUZ, E; MORENO, R; LISBOA, C
    We studied the effects of an 8-h, once-a-week schedule of cuirass ventilation (CV) in 5 patients with advanced chronic air-flow limitation and chronic hypercarbia (PaCO2, 58.6 .+-. 10.1 mm Hg; mean .+-. SD). Repeated measurements of arterial blood gases, maximal inspiratory mouth pressure (Pimax), 12-min walking distance, and respiratory cycle were performed during a 1-mouth run-in period. Quality of life and transdiaphragmatic pressure were measured once. All patients completed the planned 4-month study. Four of them were ventilated for longer periods because CV could not be discontinued at the end of the study. PaCO2 showed a significant fall starting during the first month; PaO2 significantly increased from the second month, whereas Pimax significantly rose from the third month on. Maximal trnsdiaphragmatic pressure increased in the 2 patients with abnormal baseline values. The fall in PaCO2 was associated with an increase in tidal volume because of a longer inspiratory time. Significant improvements in quality of life and in the 12-min walking distance were observed. We conclude that weekly CV improves blood gases, inspiratory muscle strength, and clinical conditions of patients with chronic air-flow limitation and chronic hypercarbia, probably because of correction of chronic inspiratory muscle fatigue.