Intravenous regional anesthesia. Evaluation of 4 different additives to prilocaine

Intravenous regional anesthesia (IVRA) is an effective method of producing anesthesia of the extremities. Disadvantages are the rapid loss of anesthesia after the deflation of the tourniquet and the rapid development of postoperative pain. This study compared the effect of four different additives to prilocaine with saline on the development of a complete sensory block, on the return of sensory function after deflation of the tourniquet and on the development of postoperative pain after IVRA for minor orthopedic surgery of the arm. Seventy-five patients, ASA class 1 or 2, were randomly divided into 5 groups. All patients received 30 ml. of prilocaine 1%, together with 5 ml. of additive. In group 1, the additive was saline, in group 2 bupivacaine 0.25%, in group 3 clonidine 150 micrograms in saline, in group 4 sufentanil 25 micrograms in saline and in group 5 tenoxicam 20 mg. The development of a complete sensory block proved significantly faster in the patients receiving sufentanil (4.8 min.) as compared to plain prilocaine (7.5 min.). The return of the sensory function was comparable for all groups. Postoperative pain scores were significantly better in the clonidine and tenoxicam groups.