[Anatomic basis of continuous axillary block of the brachial plexus with thoracic reservoir]. / Bases anatómicas del bloqueo axilar continuo del plexo braquial con reservorio torácico.

Although continuous axillary block is effective for periods of up to four to six weeks, pain clinic patients with severe chronic pain in the upper extremities, mainly resulting from neuropathic disease, can require continuous drug delivery by catheter-reservoir for up to three months or longer. We studied possible locations for implanting reservoirs or catheters from the perivascular axillary space in fresh cadavers, checking for possible vascular or nerve damage after applying the usual technique for reservoir implantation. The ideal location for the reservoir is the subcutaneous tissue of the homolateral infraclavicular space of the anterior side of the thorax. The customary procedures for inserting the catheter along the subcutaneous route that extends from the perivascular axillary space to the reservoir carry no risk of damaging vascular or nerve structures.

[Subarachnoid anesthesia with minimal doses of lidocaine in ambulatory arthroscopic surgery of the knee]. / Anestesia subaracnoidea con dosis mínimas de lidocaína en la cirugía artroscópica de rodilla en régimen ambulatorio.

The objective is demonstrate that subarachnoid anesthesia with 2% isobaric lidocaine at low doses (0.5 mg/kg) is safe and effective for outpatient arthroscopic surgery of the knee. This was a prospective study of 150 ASA I-III patients undergoing arthroscopic knee surgery as outpatients under subarachnoid anesthesia. With no prior vascular filling, we provided blockade by administering 2% isobaric lidocaine at a dose of 0.5 mg/kg through a Sprotte 25G needle without vasoconstrictor. We assessed effectiveness and degree of sensory-motor blockade, cardiovascular repercussions, recovery time (until reversal of blockade, ambulation, micturition and discharge) as well as side effects observed. The mean dose of lidocaine used was 33.44 +/- 4.16 mg. The sensory-motor blockade achieved provided optimum conditions for prevention of ischemia and the practice of the surgical procedure in all cases. Surgery lasted a mean 38 +/- 10 min. Hemodynamic changes were not clinically significant and no patients additional fluids, atropine or vasopressors. Time from start of blockade until ambulation, micturition and discharge from the recovery unit were 123 +/- 8.3, 175 +/- 12.4 and 194 +/- 13.4 min, respectively. Micturition was spontaneous in all cases. Complications recorded were cephalea and backache. In conclusion, subarachnoid anesthesia at low doses of 2% isobaric lidocaine provides excellent conditions for practicing arthroscopic surgery of the knee on outpatients, with minimum side effects.