Chest physiotherapy in chronic obstructive pulmonary disease: forced expiratory technique combined with either postural drainage or positive expiratory pressure breathing.

The aim of this study was to measure the short-term effects on mucus clearance after forced expiratory technique (FET) combined with either postural drainage (PD) or positive expiratory pressure breathing (PEP) on two different days. We also wanted to assess the patient's preference to the two methods. We measured mucociliary clearance at rest and during physiotherapy in 14 patients with chronic obstructive pulmonary disease. The subjects inhaled an aerosol containing 99mTc-labelled albumin colloid. Five sets of scintigraphic images were obtained with 22-min intervals. Lung retention of radioactivity was quantified using a gamma camera and the clearance of particles from the lungs calculated for each 22-min period. The first image was obtained directly after inhalation, the second after a period of 22 min rest, the third after physiotherapy and the fourth and fifth images after further periods of rest. Clearance from the whole lung and from central and peripheral regions were much greater after physiotherapy than at rest. Clearance during PD+FET was significantly higher than during PEP+FET in the total lung field (P < 0.05) and in the peripheral region (P < 0.004). The patients found the two methods equally efficient but most of the patients preferred PEP as a treatment.

Quantitative evaluation of aerosol deposition pattern in the lung in patients with chronic bronchitis.

A number of numeric measurements have been suggested to describe the pattern of deposition of inhaled aerosols, but there is little information about the relationship between the different measurements. We compared four different methods for analysis of aerosol deposition pattern with respect to their ability to separate patients with chronic bronchitis (CB) from healthy subjects, and with respect to their relationship to a simple index of airflow obstruction. Twelve healthy subjects and 22 patients with CB were studied. All the subjects inhaled a radiolabelled aerosol produced with an air-jet nebulizer. The aerosol contained albumin millimicrospheres labelled with 99Tcm. The ratio of peripheral to central deposition--the penetration index, the coefficient of variation, the coefficient of skewness and the quotient between maximum and mean value deposition were calculated using a gamma camera. The differences between the patients and the healthy subjects were statistically significant for all variables (p < 0.001). The sensitivity of measurements of aerosol deposition for detection of CB was similar to that of forced expiratory volume in one second (FEV1). We found strong correlations between the indices of aerosol deposition and FEV1 between all indices. In clinical routine practice, studies of aerosol deposition offer little advantage in the evaluation of patients with CB. Any of the indices may be suitable for evaluation of aerosol deposition in e.g. studies of inhaled pharmaceuticals.

Immediate effects of ethanol on mucociliary clearance in healthy men.

A recent experimental study has shown that ethanol concentrations below 1% increase ciliary beat frequency in preparations of sheep trachea. This study was designed to investigate whether low ethanol concentrations also increase mucociliary clearance in man. Mucociliary clearance was measured using inhaled, radiolabelled particles. Clearance was measured in normal men for 30 min under baseline conditions. The subjects then ingested 28 g of ethanol, and clearance was measured for a further 40 min. The subjects reached a mean plasma concentration of 0.04% 30 min after ethanol intake. The mean half-life of the radioactive particles in the lung was 160 min under basal conditions and 257 min after ethanol ingestion. The difference was not statistically significant. We conclude that low ethanol concentrations do not increase mucociliary clearance in man.

Mucus clearance at rest and during exercise in patients with bronchial hypersecretion.

The purpose of this study was to measure the effects on mucus clearance after physical exercise. We measured mucociliary clearance at rest and during exercise in eleven patients with mild or moderate bronchial hypersecretion. The subjects inhaled an aerosol containing 99mTc-labelled albumin millimicrospheres. Four sets of scintigraphic images were obtained with 15 minute intervals. The lung retention of radioactivity was quantified using a gamma camera and the clearance of particles from the lungs were calculated for each 15 min period. The first image was obtained directly after inhalation, the second after a period of 15 min rest, the third after a period of exercise on a bicycle ergometer and the final fourth image after another period of rest. We found no differences in the clearance rate at rest and after exercise.

Mucociliary clearance in healthy men at rest and during exercise.

We measured mucociliary clearance at rest and during exercise in 11 healthy non-smoking men. The subjects inhaled an aerosol containing [99Tcm]albumin millimicrospheres with deep inhalations. Four sets of scintigraphic images were obtained with 15-min intervals. Lung retention of radioactivity was quantified using a gamma camera and the clearance of particles from the lungs calculated for each 15-min period. The first image was obtained directly after inhalation, the second after a period of 15-min rest, the third after a period of exercise on a bicycle ergometer (workload approximately 80% of predicted maximum capacity) and the final fourth image after another period of rest. We found small differences in clearance rate at rest and during exercise indicating that there is no substantial change in the clearance rate during exercise in normal subjects.