A comparison between the 133Xe washout and laser Doppler techniques for estimation of nasal mucosal blood flow in humans.

Measurements of blood flow in the human nasal mucosa can be performed with 133Xe washout technique and with laser doppler flowmetry. These methods are based on different principles and a comparison of the methods is of interest. For this purpose the 133Xe washout and laser doppler techniques were used to evaluate the effect of topical xylometazoline and noradrenaline on blood flow. Xylometazoline was found to induce a dose-dependent decrease in nasal mucosal blood flow, as registered with both methods. After noradrenaline, no change in blood flow was seen in 133Xe washout measurements, whereas a reduced blood flow was registered with laser doppler flowmetry. It is concluded that the 133Xe washout technique and laser doppler flowmetry reflect blood flow in different parts of the vascular bed in the human nasal mucosa, which means that they complement each other in such investigations.