Changes in mucociliary clearance during acute exacerbations of asthma

MS Messina, TG O'riordan… - American Review of …, 1991 - atsjournals.org
MS Messina, TG O'riordan, GC Smaldone
American Review of Respiratory Disease, 1991atsjournals.org
Previous studies have suggested that mucociliary clearance (MC) is Impaired in asthmatic
subjects. If so, impaired clearance may be an important factor in acute exacerbation. We
proposed that if MC plays a significant role in acute illness, MC should be impaired during
the exacerbation but improve after recovery. To test this hypothesis, five asthmatic patients
with attacks requiring hospitalization underwent measurement of MC using radlolabeled
aerosol and a gamma camera. They were studied on the second or third day after admission …
Previous studies have suggested that mucociliary clearance (MC) is Impaired in asthmatic subjects. If so, impaired clearance may be an important factor in acute exacerbation. We proposed that if MC plays a significant role in acute illness, MC should be impaired during the exacerbation but improve after recovery. To test this hypothesis, five asthmatic patients with attacks requiring hospitalization underwent measurement of MC using radlolabeled aerosol and a gamma camera. They were studied on the second or third day after admission with repeat measurements after discharge. Spirometry was performed before all studies. After an equilibrium xenon scan (133Xe), which defined lung borders and measured regional volume, radiolabeled saline particles containing technetium-labeled (99mTc) sulfur colloid were deposited and used to label airway mucus. Deposition patterns were matched by regulating particle distribution and breathing pattern. MC was then measured as percentage retention of radioactivity at 10-min Intervals for 2 h. When hospitalized, 96.0 ± 2.06% (SEM) of the initial radioactivity was retained in the lung after 2 h, indicating little clearance of mucus from the lung. In fact, no significant changes were detected when activity at 120 min was compared with measurements at 10 min (99.2 ± 0.22%, NS). After discharge clearance was markedly enhanced. That is, retention of lung activity was significantly lower at all time intervals from 10 min onward, with only 70.9 ± 3.86% retained at 120 min (p = 0.008). During an asthmatic attack warranting hospital admission, MC is significantly impaired, with marked improvement following recovery. Although a causal relationship remains to be established between mucociliary impairment and the clinical features of an acute exacerbation of asthma, the association demonstrated in this paper suggests that MC assessment may yet provide a further objective means of assessing the severity of a patient's asthma and the response to therapy.
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