Inhaled mannitol for the treatment of mucociliary dysfunction in patients with bronchiectasis: effect on lung function, health status and sputum.
OBJECTIVE
Inhaled mannitol increases mucus clearance in patients with bronchiectasis by an unclear mechanism. The effect of mannitol on lung function, health status and sputum properties was investigated.


METHODS
Nine patients with bronchiectasis inhaled 400 mg of mannitol once daily for 12 days. Health status was assessed using the St George's Respiratory Questionnaire (SGRQ). Sputum was analysed for viscosity, elasticity, spinnability, surface tension, contact angle, solids, mucociliary transportability (MCTR) on a frog palate, and cough transportability (CTR) on a simulated cough machine.


RESULTS
Lung function was unchanged with treatment (baseline FEV1 82.0 +/- 16.2%) apart from an improvement in FEF from 85.4 +/- 13% (baseline) to 90.7 +/- 14.4% (P < 0.05; 12th treatment; visit 7). The total SGRQ score (mean +/- SD) of 49.3 +/- 13.8 at baseline, decreased by 12.4 +/- 10.2 (P < 0.01; visit 7) and 10.1 +/- 9.4 units (P < 0.02) 6-10 days after treatment cessation. The baseline subscores for symptoms (72.9 +/- 11.8), activity (44.7 +/- 20.9) and impact (44.4 +/- 14.3) were reduced by 0.8 +/- 9.1 (P > 0.7), 8.4 +/- 16.0 (P > 0.1) and 19.2 +/- 13.7 (P < 0.005) units, respectively (visit 7). Mannitol reduced the baseline (mean +/- SE) surface tension from 94.5 +/- 1.4 to 84.7 +/- 2.1 mN/m (P < 0.0001), contact angle from 51.1 +/- 2.8 to 33.2 +/- 2.4 degrees (P < 0.0001), spinnability from 11.6 +/- 0.4 to 10.0 +/- 0.2 mm (P < 0.005), and solids from 5.7 +/- 0.4 to 4.3 +/- 0.7% (P < 0.02), acutely (visit 7). Viscosity, elasticity and MCTR did not change significantly, while CTR was increased from 25.8 +/- 1.0 to 34.1 +/- 2.7 mm (P < 0.003).


CONCLUSIONS
Mannitol significantly improved the health status over 12 days and this improvement was maintained for 6-10 days after cessation of treatment. In addition, mannitol reduced the tenacity, increased the hydration of mucus acutely and improved cough clearability in patients with bronchiectasis.
Daviskas
Evangelia
E
Department of Respiratory Medicine, Royal Prince Alfred Hospital, Sydney, NSW, Australia. daviskas@mail.med.usyd.edu.au
Anderson
Sandra D
SD
Gomes
Kerry
K
Briffa
Peter
P
Cochrane
Belinda
B
Chan
H-Kim
HK
Young
Iven H
IH
Rubin
Bruce K
BK
D000280:Administration, Inhalation; D000368:Aged; D001987:Bronchiectasis / Q000188:drug therapy* / Q000503:physiopathology; D003371:Cough / Q000503:physiopathology; D004548:Elasticity; D005100:Expectorants / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D008168:Lung / Q000187:drug effects*; D008297:Male; D008353:Mannitol / Q000008:administration & dosage*; D008450:Maximal Midexpiratory Flow Rate / Q000187:drug effects; D008875:Middle Aged; D009079:Mucociliary Clearance / Q000187:drug effects* / Q000502:physiology; D012123:Pulmonary Ventilation / Q000187:drug effects; D011788:Quality of Life; D013183:Sputum / Q000737:chemistry / Q000187:drug effects*; D013500:Surface Tension; D014783:Viscosity; D017155:Wettability
D005100:Expectorants; D008353:Mannitol