Catheters for neural blockade: Materials and designs

Anesthesia has progressed leaps and bounds from the days of ether, cocaine, a finger on the pulse, and an eye on the patient. Neural blockade has advanced from topical application and local infiltration to continuous anesthesia and analgesia of neural compartments. Advances in pharmacology, neural physiology, and materials and designs have markedly broadened the applications of neural blockade over the past century. Continuous techniques have advanced from indwelling needles to catheters of multiple materials and designs. We have reviewed the literature in order to discuss the catheters available today, the materials used, the different design characteristics and their advantages and disadvantages. In particular, the controversies involving single-versus multiorifice epidural catheters and the use of microcatheters for continuous spinal anesthesia are examined. The ideal catheter would combine ease of placement and consistently excellent neural blockade with no complications. However, while awaiting its arrival, we must choose among the catheters currently available.