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Biomedical subjects

H Sala

Publications and source records attributed to H Sala.

7 recordsLinked to original sources
PubMed1996

Relationship between supramaximal flows and flow-limiting mechanisms.

The aim of this study was to evaluate the relationship between supramaximal flows (SF) and indices of airway mechanics. We studied 26 asymptomatic young subjects (13 smokers, mean +/- SD 15.9 +/- 6.6 pack-years. Subjects performed maximal expiratory flow-volume (MEFV) curves, according to the American Thoracic Society (ATS) criteria, on a rolling-seal spirometer and then repeated them through a specially devised valve, which occluded the mouthpiece either 3 or 6 times.s-1 with a ratio of open:closed time of 3:1. Envelope MEFV curves for 3 and 6 Hz occlusions were constructed passing through the SF obtained after each occlusion, and the increment in flow at 50% of vital capacity was measured with respect to the basal curve (delta V' max50). We found that the delta V' max50 at 3 and 6 Hz correlated to the baseline forced mid-expiratory flow (FEF25-75) in % of predicted value (r = -0.73 and r = -0.55, respectively). our results suggest that inhomogeneities within the lung are an important mechanism in the occurrence of supramaximal flow in normal subjects.

Adult↗
PubMed1992

Effects of inhaled platelet activating factor on bronchial responsiveness in patients with symptomatic and asymptomatic pulmonary embolism.

To determine the possible role of platelet-activating factor (PAF) in pulmonary embolism (PE), the reactivity of the airways to inhaled PAF, using doses ranging from 6.25 to 400 micrograms, was examined in 24 patients with a past episode of PE. Twelve of these patients had experienced acute respiratory insufficiency during the episode (with or without additional symptoms). None of the remaining 12 patients had experienced any respiratory symptoms during the PE episode. Diagnosis was established by means of a ventilation-perfusion lung scan performed when admitted to the hospital because of deep venous thrombosis (DVT) in the lower limbs. Nonspecific bronchial reactivity as measured by the response to bronchoprovocation testing with methacholine showed no significant differences between both groups. PAF caused a dose-dependent bronchoconstriction defined by at least a 35 percent decrease in specific airway conductance (SGaw) in all patients. The average dose of PAF needed to decrease SGaw 35 percent was significantly lower in patients who had had a symptomatic PE than in those with asymptomatic PE (p = 0.011). This finding suggests that patients who suffered from symptomatic PE may present a greater airway reactivity to inhaled PAF. This different behavior might explain the existence of some of the respiratory symptoms of PE, which could be attributed to PAF-related effects. However, additional studies are needed to evaluate the role of PAF in PE.

Administration, Inhalation↗
PubMed1991

Hygroscopic condenser humidifier as a solution to nasal dryness due to nasal CPAP treatment for obstructive sleep apnea syndrome.

We report an apparent solution to nasal dryness for patients with obstructive sleep apnea syndrome treated with nasal continuous positive airway pressure (CPAP) when a hygroscopic condenser humidifier is introduced into the CPAP circuit. Six patients underwent a 5-h test period of nasal CPAP therapy with a mask containing a hygroscopic humidifier. The water vapor showed a statistically significant increase in both inspired and expired gases. The relative humidity of the inspired gases increased significantly. The levels of O2 and CO2 in the respired gases did not change. When patients were asked about nasal dryness at the end of the test, all of them reported marked improvement.

Air Conditioning↗
PubMed1986

Captopril and bronchial reactivity.

In order to assess the effect of captopril on bronchial reactivity, 16 consecutive patients with asthma and hypertension were randomized in a double-blind crossover study, with increasing doses of placebo or captopril for 4 week periods. Forced expiratory flow (FEV1) and a dose-response curve with methacholine (PD20) were measured before and after treatment . Effective control of hypertension was achieved in all patients on captopril (P less than 0.05), while no changes in FEV1 and PD20 were observed. We conclude that captopril can be used as a first step in the treatment of asthmatic patients with hypertension.

Asthma↗
PubMedDate not supplied

Evaluation of a new piston-type spirometer.

A new dry spirometer (DS) incorporating a microcomputer for automatic calculation and direct read-out of spirometric parameters was compared to a calibrated Fleisch pneumotachograph (PT). Twenty-eight volunteers, including healthy subjects, obstructive and non-obstructive patients, performed a total of 48 spirometric tests with the two apparatuses randomly alternated. DS values for FVC were lower than those of the PT with a mean difference of 0.177 1 +/- 0.171 SD (p less than 0.0001). Mean FEV1 values were very similar in both apparatuses with a non significant difference of 0.003 1 +/- 0.182 FEF25-75 values were higher with the DS, showing a mean difference with the PT of 0.407 1 . s-1 +/- 0.324 (p less than 0.00001). The DS also gave slightly higher PEFR values than the PT, with a mean difference of 0.310 1 . s-1 +/- 0.830 (p less than 0.02). Differences in FVC readings between DS and PT were greater in severely obstructed patients (0.350 1 +/- 0.084, p less than 0.0001) than among healthy subjects (0.120 1 +/- 0.051, p less than 0.0002). On the contrary, in absolute figures DS values for FEF25-75 showed a greater difference with those of the PT in normals (0.547 1 . s-1 +/- 0.320, p less than 0.001) than in obstructed patients (0.288 1 . s-1 +/- 0.244, p less than 0.05). DS flow resistance was 2.67 cmH2). s. 1-1 for a flow of 8.8 1. s-1. Based on the spirometric differences observed, and on the high flow resistance and volume limitation imposed by its 6 1 capacity, we concluded that the apparatus tested cannot be recommended for clinical spirometry.

Adult↗