Renck H, Hassan H G, Lindberg B, Akerman B
Department of Anaesthesia, Malmö General Hospital, Sweden.
Acta Anaesthesiol Scand. 1988 Jul;32(5):355-64. doi: 10.1111/j.1399-6576.1988.tb02745.x.
Sodium hyaluronate (HA) and dextran (Dx) of different molecular weights and concentrations were used as adjuvants to prilocaine for studies of the duration of infraorbital nerve block in the rat (IONB) and spinal anaesthesia in the mouse (SA). A positive relation was found between duration of block on the one hand and the concentration as well as the molecular weight of the adjuvant on the other. A direct relation was found between the duration of block and the viscosity of the anaesthetic solution. Low-sodium-content solutions of plain prilocaine caused a markedly prolonged duration of the most profound degrees of IONB as compared to medium- or high-sodium-content solutions, while no differences between the solutions were found for the weakest intensity of IONB studied or for SA. Solutions of low-sodium-content containing prilocaine and HA were associated with significant prolongations of IONB and SA as compared to corresponding solutions of medium- or high-sodium content. Inclusion of adrenaline, 5 micrograms/ml, in solutions containing prilocaine and Dx significantly prolonged the duration of the most profound degrees of IONB and of SA. By contrast, the inclusion of adrenaline in solutions containing prilocaine and HA did not prolong the duration of IONB or SA. It is concluded that modulations of the viscosity of local anaesthetic solutions by the addition of macromolecular compounds strongly affect the duration of peripheral and central nerve blocks in experimental animals. A further prolongation is accomplished by reducing the sodium content of the solutions and, in the case of Dx-containing solutions, by inclusion of adrenaline in the anaesthetic solution. The possible mechanisms of these actions are discussed.
将不同分子量和浓度的透明质酸钠（HA）和右旋糖酐（Dx）用作丙胺卡因的佐剂，用于研究大鼠眶下神经阻滞（IONB）的持续时间和小鼠脊髓麻醉（SA）。结果发现，一方面阻滞持续时间与佐剂的浓度及分子量之间呈正相关。另一方面，阻滞持续时间与麻醉溶液的粘度呈直接关系。与中钠含量或高钠含量溶液相比，普通丙胺卡因的低钠含量溶液可使最深程度的眶下神经阻滞持续时间显著延长，而在所研究的最弱强度的眶下神经阻滞或脊髓麻醉方面，各溶液之间未发现差异。与相应的中钠含量或高钠含量溶液相比，含丙胺卡因和透明质酸钠的低钠含量溶液可使眶下神经阻滞和脊髓麻醉的持续时间显著延长。在含丙胺卡因和右旋糖酐的溶液中加入5微克/毫升肾上腺素可显著延长最深程度的眶下神经阻滞和脊髓麻醉的持续时间。相比之下，在含丙胺卡因和透明质酸钠的溶液中加入肾上腺素并不会延长眶下神经阻滞或脊髓麻醉的持续时间。得出结论，通过添加大分子化合物调节局部麻醉溶液的粘度会强烈影响实验动物外周和中枢神经阻滞的持续时间。通过降低溶液的钠含量，以及在含右旋糖酐的溶液中，通过在麻醉溶液中加入肾上腺素可进一步延长阻滞时间。讨论了这些作用的可能机制。
