Equipment and Safety Conditions

Selection of suitable equipment for plexus and mixed nerves blocks

Mixed nerves trunks and plexuses are best localized by using electrical stimulation to elicit twitches in supplied muscles. The intensity of delivered current is critical and has been prospectively evalua-ted during humeral blocks in adults.[33] This recent publication confirms previous empirical findings: muscle twitches should be elicited at intensities ranging from 0.5 to 0.8 mA to guarantee high success rate (>95%) of blockade. Sheathed needles of adequate length are the most appropriate for both safety and precision, provided they have a short-bevel or a pinpoint tip. More sophisticated devices have recently been suggested to allow insertion of a catheter either through a cannula mounted over a metallic blunt needle, or directly through the insulated needle connected to a nerve stimulator. More recently, the catheter itself, with a built-in spiraled metallic wire, can be connected to the nerve stimulator, thus allowing its precise placement in close contact to the relevant nerve path. These catheters can be connected to infusion pumps or inflatable bags allowing precise delivery of LA, either continuously or on-demand, over long periods of time.

Selection of a suitable equipment for compartment blocks

Precise identification of fascial planes is the essential step of compartment blocks such as the fascia iliaca compartment block. To achieve this goal, it is necessary to use a short-beveled needle that allows good identification of the relevant fascial plane. Using this kind of needle also improves considerably the safety of the procedure. Several commercially available short-beveled needles, including pediatric Tuohy needles, allow safe placement of a catheter along the inner surface of the relevant fascial plane, thus permitting continuous infusion or intermittent injections of anesthetic solutions for both passive and active (reeducation and joint mobilization) postoperative pain relief.