[Electrolyte concentration, real and osmotic pressure in abscesses].

Electrolyte concentrations, osmotic and hydrostatic pressures of 26 abscesses in the head and neck area were measured. As the main cations Sodium (138 +/- 38 mmol/l) and Potassium (37 +/- 16 mmol/l and as anions Chloride (183 +/- 46 mmol/l) and Bicarbonate (10 +/- 4 mmol/l) were identified. The pH-value of the pus liquid decreased to 6.164 +/- 0.233. The calculated mean osmotic pressure of the pus liquid was 7910 +/- 1455 mm Hg whereas the measured physical pressure inside the abscess was 49 +/- 13 mm Hg. As a consequence of being an osmotically active system the inactivity of antibiotics in abscesses may be explained by a lack of diffusion through the abscess membrane, due to electrochemical charges or the size of the molecule, or by lack or reduction of the capillary perfusion and ultrafiltration rate due to physical pressure of the abscesses on perifocal blood vessels.