The acceptance of regional anaesthesia has been limited by two major factors inherent in the local anaesthetic agents available for use, slow onset time and short duration of action. Hence, the use of mixtures of local anaesthetics for regional anaesthesia has become relatively popular in recent years. The basis for this practice is to compensate for the short duration of action certain agents such as lidocaine and long latency of other agents such as bupivacaine. Penetration of local anaesthetics into the neural tissues may be increased by alkalinization. Single dose of lumbar epidural blockade was instituted for orthopedic, urologic, perianal and lower abdominal surgery in 62 patients who were randomly assigned to three treatment groups. Groupl (n=20) received bupivacaine HCI, 0.5 percent; group II (n=22) a mixture containing bupivacaine HCI, 0.25 percent and lidocaine HCI, 1 percent; and group III (n=20) a mixture containing bupivacaine HCI, 0.25 percent, lidocaine HCI, 1 percent and NaHC03, 8.4 percent 1 ml/10 ml solution. Onset of analgesia to pin prick was significantly faster in group HI than group I and group41 ll(p<0.01). There were no significant differences between the group I and group ll(p>0.05). The duration of analgesia was significantly shorter in group III than group I and group ll(p<0.01). There were no significant differences between the group I and group ll(p>0. 05). This study shows that a mixture of bupivacaine and lignocaine provided an excellent alternative to bupivacaine alone. By reducing the dose of bupivacaine used, the combination may reduce the risk of cardiotoxicity. Alkalinization provides shorter analgesia onset time.

Mevcut lokal anesteziklerin yavaş etki göstermeleri ve etkilerinin kısa olması gibi iki temel faktör, rejional anestezi kullanılmasını sınırlar. Bu yüzden son yıllarda rejional anestezide lokal anesteziklerin karışımlarının kullanılması güncellik kazanmıştır. Bu uygulamanın temelinde lidokain gibi kısa etkili ve bupivakain gibi geç etkili ajanların olumsuzluklarının ortadan kaldırılması rol oynamaktadır. Lokal anesteziklerin sinir dokusuna geçişi, alkalinizasyonla artırılabilir. Ürolojik, ortopedik, perianal ve alt karın ameliyatı yapılan ve rastgele üç gruba ayrılan 62 hastaya tek doz lomber epidural blok uygulandı. Grup l'e %0.5 bupivakain HCI, Grup N'ye %0.25 bupivakain HCI ve %1 lidokain HCI karışımı, Grup lll'e ise bu karışıma her 10 ml'ye 1 mi %8.4'lük NaHC03 eklenmesiyle elde edilen karışım verildi.41 ll(p<0.01). There were no significant differences between the group I and group ll(p>0.05). The duration of analgesia was significantly shorter in group III than group I and group ll(p<0.01). There were no significant differences between the group I and group ll(p>0. 05). This study shows that a mixture of bupivacaine and lignocaine provided an excellent alternative to bupivacaine alone. By reducing the dose of bupivacaine used, the combination may reduce the risk of cardiotoxicity. Alkalinization provides shorter analgesia onset time.