technetium-tc-99m-sulfur-colloid and Cough

A standardized protocol for measuring mucociliary (MCC) and cough clearance (CC) was developed and tested at the University of North Carolina at Chapel Hill, NC (UNC), Johns Hopkins University (JHU), and the University of Pittsburgh (Pitt).. A total of 50 healthy nonsmoking adults with normal lung function were studied at the three sites: 30 [21 males/9 females (21M/9F)] at UNC, 10 (6M/4F) at JHU, and 10 (4M/6F) at Pitt. Subjects inhaled an aerosol of (99m)technetium sulfur colloid in 0.9% saline (mass median aerodynamic diameter=5.4 μm) under controlled breathing conditions (500 mL/sec, 30 breaths/min) by following a metronome and flow signal from a commercial dosimeter. Following inhalation, subjects sat in front of a gamma camera as sequential lung images were acquired for 60 min. Subjects then coughed 60 times, and images were acquired after each set of 20 coughs, i.e., at 70, 80, and 90 min. Subjects returned to the laboratory approximately 24 hr later for a final image of residual lung activity. Initial aerosol distribution was measured as a central/peripheral (C/P) ratio of activity. MCC/CC was expressed as the area under the retention versus time curve over 90 min (AUC90).. A multivariate analysis of clearance versus time with site and C/P as covariates showed no significant site-specific differences. Interestingly, MCC/CC was greater in females (n=19) versus males (n=31), with AUC90=0.84 ± 0.11 and 0.90±0.07, respectively (p=0.03), for the combined data set from all sites (not significant for any given site). There were no gender differences for either C/P ratio or 24-hr clearance.. This standardized protocol may prove beneficial in multicenter trials for testing new therapies that are designed to improve MCC/CC.

Topics: Administration, Inhalation; Adolescent; Adult; Aerosols; Area Under Curve; Cough; Female; Humans; Lung; Male; Mucociliary Clearance; Multivariate Analysis; Radionuclide Imaging; Sex Factors; Technetium Tc 99m Sulfur Colloid; Time Factors; Tissue Distribution; Young Adult

Indirect evidence suggests that induced sputum derives from the surfaces of the bronchial airways. To confirm this experimentally, we employed a radiolabeled aerosol bolus delivery technique that preferentially deposits aerosol in the central airways in humans. We hypothesized that there would be significantly more radioactivity recovered in an induced sputum sample, and greater airways clearance of radiolabeled particles, immediately after a central versus peripheral airways deposition. Ten healthy volunteers underwent radiolabeled aerosol deposition ((99m)Tc sulfur colloid particles) to the central and peripheral airways on separate occasions followed immediately by induced sputum or no sputum (control), while seated in front of a gamma camera. Radioactivity was measured in the selected sputum sample, processed cell pellet, and supernatant fraction. Significantly more radioactivity was present in all portions of the sputum sample after central versus peripheral airways deposition (i.e., selected sample: 15,607 counts +/- 2,985 versus 943 counts +/- 298, p = 0.001). Clearance from the whole lung was significantly greater 40 min after central versus peripheral airways deposition (48 +/- 3% versus 5 +/- 1%, p = 0.0001). Compared with control, induced sputum greatly enhanced clearance after central deposition (48 +/- 3% versus 11 +/- 6%, p = 0.0001), but not after peripheral deposition (5 +/- 1% versus 3 +/- 0.8%). These results provide direct evidence that induced sputum derives from the central airways with little or no contribution from the peripheral airways.

Topics: Administration, Inhalation; Adolescent; Adult; Aerosols; Cough; Female; Forced Expiratory Volume; Humans; Isotope Labeling; Leukocyte Count; Lymphocytes; Macrophages, Alveolar; Male; Mucociliary Clearance; Neutrophils; Particle Size; Radionuclide Imaging; Radiopharmaceuticals; Specimen Handling; Sputum; Technetium Tc 99m Sulfur Colloid; Time Factors; Vital Capacity

In patients with cystic fibrosis (CF), dehydration of airway secretions leads to a decrease in mucociliary clearance (MCC). We examined the acute effect of MCC of a single administration by aerosolization of hypertonic saline (7%) (HS), amiloride (0.3% in 0.12% NaCl) (AML) and a combination of AML and HS (AML + HS) in 12 patients with CF using a radioaerosol technique. Isotonic saline [0.9%] (IS) was used as a control solution. As both the AML and HS solutions induced cough in some patients, the last nine patients studied also underwent a cough clearance day. This was to eliminate the possible confounding effect of cough on MCC measurement. Patients ranged from 18 to 28 yr (mean +/- SD, 22 +/- 3) with an FEV1 of 27 to 112% predicted (61 +/- 30%). Following deposition of the radioaerosol, baseline clearance was assessed for 30 min. This was followed by a 30-min intervention period. Assessment of post-intervention clearance for a further 30 min was then performed. Comparison of the amount of radioaerosol cleared from the right lung was made at 60 min (%C60) and 90 min (%C90) using repeated measures ANOVA. The percent cleared at 60 and 90 min was significantly increased with HS (%C60 = 26.5%, %C90 = 29.4%) and the combination of AML + HS (%C60 = 23.1%, %C90 = 27.4%) compared with both IS (%C60 = 14.7%, %C90 = 17.5%) and COUGH (%C60 = 18.0%, %C90 = 19.5%), p < 0.01. Inhalation of hypertonic saline is a potentially useful treatment in patients with cystic fibrosis.

Topics: Adolescent; Adult; Aerosols; Amiloride; Analysis of Variance; Confounding Factors, Epidemiologic; Cough; Cystic Fibrosis; Drug Combinations; Expectorants; Female; Forced Expiratory Volume; Humans; Isotonic Solutions; Lung; Male; Mucociliary Clearance; Saline Solution, Hypertonic; Technetium Tc 99m Sulfur Colloid

Pulmonary aspiration was assessed using a scintigraphic swallowing procedure in 14 dysphagics in whom penetration of the larynx had been previously diagnosed. No patient had recent evidence of aspiration pneumonia. Imaging was performed during and following ingestion of a cupful of thin liquid admixed with between 1-2 mCi of Tc-99m sulfur colloid. Follow-up scans were obtained several hours later as needed to assess airway clearance. Five of the fourteen (36%) showed penetration distal to the trachea. Seven (50%) were indeterminate for aspiration, as isotope localized to the neck could not be clearly designated as being in either airway or foodway. Two subjects had negative studies. Of patients with subtracheal penetration, (1) fractions of the ingested material which were aspirated ranged from < 1%-25%, and (2) elimination from airways was complete or near-complete by 3 hours. The presence of an immediate or delayed cough was noted but did not correlate with subtracheal aspiration. Based on the results of scintigraphy, 8 of 9 patients on some form of liquid restriction at the time of testing were allowed to ease restrictions. Five patients without prior liquid restriction were allowed to continue to drink. We propose that scintigraphy provides important data on airway penetration and clearance that is useful in the dietary management of dysphagic patients.

Topics: Adult; Aged; Cough; Deglutition; Deglutition Disorders; Foreign Bodies; Humans; Inhalation; Larynx; Middle Aged; Mucociliary Clearance; Radionuclide Imaging; Severity of Illness Index; Technetium Tc 99m Sulfur Colloid; Trachea