M Klinger1, R Siegert. 1. Klinik für HNO-Heilkunde der Med. Universität Lübeck.
Abstract
BACKGROUND: Nasal packings are commonly accepted in the treatment of severe epistaxis. Cuffed catheters are known to cause damage to the nasal mucosa most likely by interfering with tissue perfusion. In this study the effect of different pressure levels on local perfusion of septal mucosa is investigated. METHOD: In 15 healthy subjects the blood flow in septal mucosa was measured by laser doppler flowmetry by positioning a cuffed epistaxis catheter into the nasal cavity with a laser probe attached to it. Increasing pressure was administered by injecting saline solution while continuously recording intraluminal pressure, perfusion, and filling volume. The local pressure affecting the septal mucosa at the moment of stalling perfusion was determined by subtracting the extranasal cuff pressure from the current intranasal cuff pressure at same inflation volumes. RESULTS: Microcirculation of the septal mucosa stopped when the local pressure exceeded a value of Pmean = 42 mmHg. Individual variations (n = 15) were small (s = 9 mmHg). The intraluminal 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. CONCLUSIONS: 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 several times higher than the actual local pressure. This effect may cause problems in the proper use of cuffed catheters. Laser doppler flowmetry proved to be helpful in determining reproducible perfusion values.
BACKGROUND: Nasal packings are commonly accepted in the treatment of severe epistaxis. Cuffed catheters are known to cause damage to the nasal mucosa most likely by interfering with tissue perfusion. In this study the effect of different pressure levels on local perfusion of septal mucosa is investigated. METHOD: In 15 healthy subjects the blood flow in septal mucosa was measured by laser doppler flowmetry by positioning a cuffed epistaxis catheter into the nasal cavity with a laser probe attached to it. Increasing pressure was administered by injecting saline solution while continuously recording intraluminal pressure, perfusion, and filling volume. The local pressure affecting the septal mucosa at the moment of stalling perfusion was determined by subtracting the extranasal cuff pressure from the current intranasal cuff pressure at same inflation volumes. RESULTS: Microcirculation of the septal mucosa stopped when the local pressure exceeded a value of Pmean = 42 mmHg. Individual variations (n = 15) were small (s = 9 mmHg). The intraluminal 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. CONCLUSIONS: 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 several times higher than the actual local pressure. This effect may cause problems in the proper use of cuffed catheters. Laser doppler flowmetry proved to be helpful in determining reproducible perfusion values.