THE INFLUENCE OF CUFFED EPISTAXIS CATHETE RS ON NASAL-MUCOSA BLOOD-FLOW MEASURED BY LASER-DOPPLER FLOWMETRY

Background: Nasal packings are commonly accepted in the treatment of s evere epistaxis. Cuffed catheters are known to cause damage to the nas al mucosa most likely by interfering with tissue perfusion. In this st udy the effect of different pressure levels on local perfusion of sept al mucosa is investigated. Method: In 15 healthy subjects the blood fl ow in septal mucosa was measured by laser doppler flowmetry by positio ning a cuffed epistaxis catheter into the nasal cavity with a laser pr obe attached to it. Increasing pressure was administered by injecting saline solution while continuously recording intraluminal pressure, pe rfusion, and filling volume. The local pressure affecting the septal m ucosa at the moment of stalling perfusion was determined by subtractin g the extranasal cuff pressure from the current intranasal cuff pressu re at same inflation volumes. Results: Microcirculation of the septal mucosa stopped when the local pressure exceeded a value of p(mean) = 4 2 mmHg. Individual variations (n = 15) were small (s = 9 mmHg). The in traluminal cuff pressure was measured to be about ten times higher due to the retraction force of the cuff. Spontaneous oscillations of the blood flow were reduced with increasing pressure to the blood vessels. Filling volumes up to 3.2 ml were sufficient to stop perfusion. Concl usions: Cuffed nasal packings stop the blood flow in nasal mucosa even at low local pressures. Depending on the material characteristics of different cuffs the pressure to dilate the cuff may, however, be sever al times higher than the actual local pressure. This effect may cause problems in the proper use of cuffed catheters. Laser doppler flowmetr y proved to be helpful in determining reproducible perfusion values.