We read with interest the comments of Blumenthal et al. on our article. 1In the reported case, the infraclavicular block was performed using a modified approach of the technique reported by Salazar et al. 2The patient lies supine with the head turned away from the arm to be anesthetized. The puncture is performed 1.5 cm internal to the coracoid process and 1.5 cm caudal to the clavicle, with the arm abducted 45 degrees. The direction of the needle is perpendicular to the operating room table (vertical technique). In general, infraclavicular block techniques attain their effect by diffusion of the anesthetics in an area close to the brachial plexus. 3Therefore, two groups of techniques can be differentiated according to the site where the infraclavicular plexus is reached. The access between the clavicle and the medial border of the pectoral minor (Salazar et al. , 2Rodríguez et al. , 3Kilka et al. , 4Wilson et al. 5) was performed in this case. Other techniques describe the access below or distal to the pectoral minor (Kapral et al. 6and Raj et al. 7). In the former, the fascicles of the brachial plexus lie grouped along the posterolateral edge of the axillar artery, and a complete block of the upper extremity can be achieved because of the anatomic proximity of the fascicles without arterial interposition. If the infraclavicular plexus is reached more distally, the interposition of the axillar artery and the division of the fascicles into the terminal nerves could lead to an incomplete block. When compared to the interscalene technique, the proposed approach has some advantages, such as the anesthetic effect on the medial fascicle (C8–T1) and the intercostobrachial nerve. However, the anesthetic effect on the superficial cervical plexus or the suprascapular nerve (obtained with the interscalene approach) would not be achieved. For those reasons, the proposed technique (vertical infraclavicular block + suprascapular block) could be even more effective than the interscalene approach.
With regard to the incidence of complications, the interscalene approach causes phrenic paresis, either by single-shot or continuous-local anesthetic infusion, but occurrence of pneumothorax is rare. Supraclavicular block produces phrenic paresis, too, but the feared complication is pneumothorax. On the other hand, the infraclavicular techniques carry a low risk for either complication, 8as does the suprascapular nerve block. Therefore, we think that the risk–benefit balance of the available techniques supports our election of the infraclavicular block.
The interesting comments of Blumenthal et al. provide us with more information and enable us to consider the infraclavicular technique, which surely will be of increasing interest among anesthesiologists in the future.