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Biomedical subjects

D Pavia

Publications and source records attributed to D Pavia.

At least 109 records · Page 6Linked to original sources
PubMed1979

Regional lung clearance of excessive bronchial secretions during chest physiotherapy in patients with stable chronic airways obstruction.

Clearance of excessive bronchial secretions labelled with inhaled radioactive polystyrene particles has been directly measured with a gamma-camera linked to a computer. Chest physiotherapy significantly increased clearance from central, intermediate, and peripheral lung regions and sputum yield. These findings confirm the value of this form of treatment, which has hitherto been in doubt, in removing excessive bronchial secretions from all lung regions and in aiding their expectoration.

Aerosols↗
PubMed1979

The effect of sodium 2-mercapto-ethane sulphonate and hypertonic saline aerosols on bronchial clearance in chronic bronchitis.

1 The efficacy of a mucolytic agent, 2-mercapto-ethane sulphonate, administered in the form of an aerosol was evaluated in a group of eleven patients with chronic bronchitis in a controlled, double-blind, crossover study. 2 Saline aerosol isotonic (1.21M, 7.1%) to the drug was used as a placebo. 3 Approximately 1 ml drug/placebo was inhaled by the patients twice a day for 3 days and a final dose was given on the mornings of the drug/placebo trial runs. 4 There was no improvement in this group of patients in lung function or subjective well being attributable to the drug. 5 The viscosity of sputum, dry macromolecular weight and N-acetyl neuraminic acid/fucose ratio remained unaltered throughout the study. 6 An enhancement of tracheobronchial clearance was obtained following the administration of either placebo (31%) or drug aerosols (24%) Statistical significance (P less than 0.01) was only achieved for the placebo and was attributed to an increase in sputum volume.

Aerosols↗
PubMed1979

Effect of ipratropium bromide on mucociliary clearance and pulmonary function in reversible airways obstruction.

The effects of (a) regular use for one week and (b) a single dose of a synthetic anticholinergic (ipratropium bromide) on lung mucociliary clearance and as a bronchodilator was ascertained in a controlled, double-blind, cross-over study in 12 patients with reversible airways obstruction (mean increase in FEV after isoprenaline: 17% range 10-50%). Two puffs from a metered dose inhaler of either placebo (propellants only) or drug (40 microgram) were administered four times a day for one week (regular use), and mucociliary clearance was measured, by radioaerosol tracer, at the end of each treatment period and after a control period in which no treatment was given. On the mornings of the measurements after the placebo and drug periods one final dose (single dose) of ipratropium (40 microgram) or placebo was given 2.5 hours before the start of the test. There was no statistically significant difference between the three mean mucociliary clearance curves (control, placebo, and drug) for the group; however, there was a significantly greater penetration towards the periphery of the lung of the tracer in the test after drug administration compared with the other two. This increased penetration was attributed to bronchodilatation caused by the drug. Ipratropium bromide does not appear to impair mucociliary clearance, and it acts an effective bronchodilator.

Aged↗
PubMed1978

The retention of lung secretions during the night in normal subjects.

1. Mucociliary clearance has been measured over a 6 h period by using the radioaerosol technique in seven normal male subjects lying supine, both during the day when awake, and during the night when asleep. 2. The percentage of radioaerosol cleared during the night, when asleep, was significantly less than during the day when awake (P less than 0.02). 3. A comparison of radioaerosol clearance before and after the time of onset of sleep demonstrates that reduced clearance occurred during sleep, indicating that this is probably a sleep-related phenomenon and not merely a result of diurnal variation. 4. This finding has important implications for patients with chronic bronchitis or asthma, in whom early morning cough or wheeze may be a predominant feature.

Adult↗
PubMed1978

Obstructive azoospermia: respiratory function tests, electron microscopy and the results of surgery.

Forty-five patients have been treated surgically for obstructive azoospermia. Fifteen underwent reversal of vasectomy and 40% of the wives became pregnant. Thirty had epididymovasostomy, and in only 2 (6.5%) did the sperm count become normal, although a few poorly motile sperms appeared in the ejaculate in a further 4 patients. Congenital abnormalities of the vasa in 7 cases and post-inflammatory blocks in 4 cases were examples of obstructive azoospermia due to well defined causes. However, in half of the patients (15 cases) the cause was obscure although it was associated with sinusitis, bronchitis or bronchiectasis (Young's syndrome). The results of pulmonary function tests in 30 cases, and electron microscopic studies of cilia from epididymes (10 cases) and bronchial mucosa (2 cases) indicated that the basic abnormality might be malfunction of the microtubules which appeared to be ultrastructurally normal in most cases. One case appeared to be associated with dietary deficiency, and correction of diet coincided with a successful result of surgery.

Adult↗
PubMed1978

Enhanced clearance of secretions from the human lung after the administration of hypertonic saline aerosol.

The radioaerosol method was used to measure the effect of saline aerosol on the rate of clearance of secretions from the lung. Two trial runs were done in each of 7 patients with chronic obstructive lung disease (mean +/- SD ratio of 1-sec forced expiratory volume for forced vital capacity, 50 +/- 15 per cent), a control run and a saline run. In both runs, 5.0 +/- 0.7-micron polystyrene particles tagged with 99mTc were inhaled under controlled conditions by the patients, and their subsequent clearance was monitored for 6 hours by whole lung counters. Scanning was also done with a gamma rectilinear scanner. The saline run was identical to the control run except that 30 min after inhaling the radioaerosol the patient inhaled an aerosol of hypertonic (1.21 M) saline for 11 min from an ultrasonic nebulizer. Although the initial distribution of the radioaerosol along the airways was the same in both runs, whole lung clearance during the first 50 min was twice as fast after the inhalation oft he hypertonic saline aerosol as in the control (P less than 0.01). The mean weight of sputum produced was higher (P less than 0.05) in the saline run. The number of coughs in the 2 runs was the same.

Aerosols↗
PubMed1977

Ipratropium bromide: mucociliary clearance rate and airway resistance in normal subjects.

The effect of ipratropium bromide, a new anticholinergic drug, on the rate of clearance of secretions from the lung and on airways resistance was investigated in 12 healthy subjects in a double-blind cross-over trial with placebo and a control run without aerosol. Before taking the drug the subjects inhaled uniform 5 micrometer tracer particles of polystyrene in which 99mTc had been unleachably incorporated. The initial depth of deposition and the rate of clearance of the particles were obtained from serial gamma counts made externally to the chest over six hours. The difference between drug, placebo and control runs in the deposition patterns of the tracer particles and their subsequent rates of clearance were not significant. The drug treatment resulted in statistically significant falls in specific airway resistance at 1, 2, 3 and 6 hours (P less than 0.02). There was no objective or subjective evidence of side effects from the drug.

Aerosol Propellants↗
PubMed1977

Effect of lung function and mode of inhalation on penetration of aerosol into the human lung.

The method using radioactive tracer particles has been applied to study the effect of the mode of inhalation of aerosols on the depth of deposition in the lungs of 50 patients with airways obstruction. The findings show that the penetration of particles is directly related to: (1) volume inspired per breath (VI); (2) forced expiratory volume in one second (FEV1); and inversely related to (3) flow rate during inhalation (V). In mathematical terms, alveolar deposition (%) = 40-3 (VI)+10-98 (FEV1)--0-75 (V)+40-4; for this regression F = 4-41 and P less than 0-01.

Adult↗
PubMed1975

No demonstrable effect of S-carboxymethylcysteine on clearance of secretions from the human lung.

The mucolytic efficacy of S-carboxymethylcysteine has been assessed in a double-blind crossover trial in 16 patients with chronic obstructive bronchitis. No significant difference was found between drug and placebo after four or seven days' treatment in the rate of clearance of secretions from the lung. This was measured by external counting of previously inhaled polystyrene tracer particles tagged with technetium-99m (99mTc). Lateral scans across the right chest after inhaling the aerosol showed equal penetration of particles towards the periphery of the lung in drug and placebo runs; this indicated that the airways had not been cleared of mucus by the drug. There was no significant difference between drug and placebo runs in the number of coughs or the weight and radioactive content of sputum voided or raised at the end of the run by chest percussion and postural drainage. Ventilatory capacity was not significantly changed nor was there any subjective improvement in the patients as a result of taking the drug.

Aged↗