Armstrong D N, Kingsnorth A N
Ann R Coll Surg Engl. 1986 Jul;68(4):207-8.
Because recent clinical trials have shown that dextran solutions can prolong the local anaesthetic action of 0.25% bupivacaine, a prospective double blind trial was performed in patients (n = 50) undergoing uncomplicated elective inguinal herniorrhaphy under local anaesthesia alone. Patients were randomised prior to infiltration of local anaesthesia into 2 groups: 0.5% bupivacaine (30 ml) diluted with an equal volume of either 0.9% saline or an equal volume of dextran 110. There was no significant difference in duration nor degree of postoperative anaesthesia between the two groups. Dextran solutions were found to be significantly more acidic than saline solutions and the possible effects of this on bupivacaine kinetics are discussed.