[The solutibility of local anaesthetics in cerebrospinal fluid and the dependency of the process on the hydrogene ion concentration (author's transl)].
Reports on in vitro precipitation of local anesthetics suggested the possibility of a damaging effect on nervous tissue with spinal anesthesia. The present assays showed that the solubility of local anesthetics in aqueous media decreases with rising pH-levels. The partial pressure of CO2 determines the pH-level of the cerebrospinal fluid, the level ranging at about 7.35 + 0.011 (95% range: 7.327-7.371). The solubilities calculated for a pH of 7.371 (at 37 degrees C) are as follows: Bupivacaine.HCl 0.83+/-0.10 mh/ml Carticaine.HCl 27 +/-2.8 mg/ml Lidocaine.HCl 24 +/-1.3 mg/ml Mepivacaine.HCl 14.8 +/- 0.2 mg/ml Tetracaine.HCl 1.4 +/- 0.12 mg/ml.
D000779:Anesthetics, Local / Q000134:cerebrospinal fluid*; D002045:Bupivacaine / Q000134:cerebrospinal fluid; D002555:Cerebrospinal Fluid; D006863:Hydrogen-Ion Concentration; D008012:Lidocaine / Q000134:cerebrospinal fluid; D008619:Mepivacaine / Q000134:cerebrospinal fluid; D012995:Solubility; D013748:Tetracaine / Q000134:cerebrospinal fluid
D000779:Anesthetics, Local; D013748:Tetracaine; D008012:Lidocaine; D008619:Mepivacaine; D002045:Bupivacaine
Löslichkeit von Lokalanaesthetika im Liquor cerebrospinalis und ihre Abhängigkeit von der Wasserstoffionenkonzentration.