title: Comparative evaluation of nasal blood flow and airflow in the decongestant response to oxymetazoline.
abstract: BACKGROUND
  Nasal blood flow (NBF) plays a crucial role in many physiological and pathological processes but its regulation and relation to other rhinological outcomes is poorly understood.
  
  
  OBJECTIVE
  We measured nasal airway patency, nasal blood flow, and subjective and objective measures of decongestion and assessed their reproducibility and responsiveness.
  
  
  METHODS
  19 healthy adults attended twice. A dose-response curve was constructed using doubling doses of oxymetazoline of 25 μg, 50 μg, 100 μg, and 200 μg at 20 minute intervals. Peak nasal inspiratory flow (PNIF) and nasal airway resistance (NAR) were measured at baseline and after each successive dose, NBF using laser Doppler flowmetry at baseline, 50 μg and 200 μg and a decongestion visual analogue scale after the final dose.
  
  
  RESULTS
  After the final dose of oxymetazoline, NBF decreased by a mean (95% CI, P value) of 139.6 (108.3-170.8, P < .001) units and 99.4 (68.1-130.7, P < .001) units, PNIF increased by 48.9 (22.0-75.8, P < .001) L.min-1 and 38.9 (12.0-65.8, P = .003) L.min-1, and NAR decreased by 0.1 (0.02-0.15, P < .001) Pa/s/cm(3) and 0.09 (0.02-0.15, P = .002) Pa.s.cm-3 at the first and second visits respectively. The area under the curve of decongestion was not significantly different between visits for each variable. The standardized response means for the decongestant response were as follows: NBF, 1.41; PNIF, 1.03; and NAR, 0.97.
  
  
  CONCLUSIONS
  Nasal blood flow using laser Doppler flowmetry is a sensitive and reproducible outcome to decongestion with oxymetazoline, similar to nasal patency and symptoms.
  
  
  BACKGROUND
  www.clinicaltrials.gov (NCT 00487032).
authors.affiliation: Asthma & Allergy Research Group, Centre of Cardiovascular and Lung Biology, University of Dundee, Dundee DD1 9SY, Scotland, United Kingdom.
authors.forename: Sriram
authors.initials: S
authors.lastname: Vaidyanathan
authors.forename: Peter
authors.initials: P
authors.lastname: Williamson
authors.forename: Brian
authors.initials: B
authors.lastname: Lipworth
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001944:Breath Tests; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D014663:Nasal Decongestants / Q000008:administration & dosage* / Q000009:adverse effects; D009666:Nose / Q000098:blood supply* / Q000502:physiology*; D010109:Oxymetazoline / Q000008:administration & dosage* / Q000009:adverse effects; D012123:Pulmonary Ventilation / Q000187:drug effects*; D012039:Regional Blood Flow / Q000187:drug effects*; D015203:Reproducibility of Results
chemical_list: D014663:Nasal Decongestants; D010109:Oxymetazoline