Anestesia

ACTA BIOMED 2008; 79: 9-17

© Mattioli 1885

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Spinal anesthesia: an evergreen technique
Simone Di Cianni1, Maria Rossi1, Andrea Casati1†, Caterina Cocco2, Guido Fanelli1
1

Department of Anesthesia and Pain Therapy, University Hospital, Parma; 2 Department of Anesthesiology and Intensive Care, University of Sassari, Sassari, Italy

Abstract. Spinal anesthesia is asimple technique that provides a deep and fast surgical block through the injection of small doses of local anesthetic solution into the subarachnoid space. The purpose of this review is to provide an overview on recent developments on local anesthetic drugs, side effects, and special techniques of intrathecal anesthesia. Spinal anesthesia can be considered adequately safe, and severe complications arereasonably rare. The cardiovascular effects associated with sympathetic block are more frequent, but successfully treated with volume expansion and administration of vasoactive drugs. It is clear that the total dose of local anesthetic injected into the subarachnoid space is the most important determinant of both therapeutic and unwanted effects of spinal anesthesia. Several studies have alsodemonstrated the efficacy and safety of using small doses of long acting agents, such as bupivacaine or ropivacaine, to produce an adequately short spinal block in outpatients. Levopivacaine, the pure S(-)-enantiomer of racemic bupivacaine showed a lower risk of cardiovascular and central nervous system (CNS) toxicity than bupivacaine. In the last years we have assisted important changes in thehealth care organization, with most of the surgical procedures performed on outpatients or on elderly patients with concomitant diseases. This forced us to change the indications and clinical use of intrathecal anesthesia techniques, which have been modified according to the changing needs of surgery. The development of new drugs and special techniques for spinal anesthesia will further improve theclinical use of this old but evergreen technique. (www.actabiomedica.it) Key words: Spinal anesthesia, local anesthetic, technique, complications

Introduction Intrathecal anesthesia allows for the production of a deep nerve block in large part of the body through the relatively simple injection of a very small amount of local anesthetic. The first report on clinical use of spinal anesthesia wasperformed in 1899 by Dr August Bier, who described the intrathecal administration of cocaine (1). Since then, a lot of experience and data had been achieved on physiology, pharmacology, and clinical application of spinal anesthesia. Moreover, technological and pharmaceutic studies have enhanced our clinical practice, while new approaches as well as special techniques have been developed to producecentral neuraxial blocks. The greatest challenge of the technique is to control the spread of the local anes-

thetic through the cerebrospinal fluid (CSF), in order to produce a block that is adequate for the proposed surgery without producing a needless extensive spread. Spinal anesthesia is a relatively simple technique, which produces adequate surgical conditions by injecting a small amountof drug with easy landmarks, giving a wide popularity to this practice. The aim of this article is to focus on the most recent achievements in terms of knowledge of pharmacology, toxicology and clinical applications of this evergreen technique.

Anatomy and physiology Several descriptions of the spinal canal anatomy have been reported since the 19th century (2), and the

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S. Di Cianni, M.Rossi, A. Casati, C. Cocco, G. Fanelli

use of modern radiological imaging technology has provided important insights in understanding anatomical and pathophysiological aspects implicated in spinal anesthesia. The vertebral level at which the spinal cord finishes varies widely from T12 to the L3/L4 intervertebral disc (3); the spinal cord extends to the L1/L2 disc in 51% of people and to the...