Author Information To the Editor: We read with great interest the recent report by Borgeat et al. regarding infraclavicular brachial plexus blockade (1) . However, we had difficulty interpreting their results in two respects. They report an impressive 97% success rate (115 patients) when a distal response was elicited (118 patients), and a 44% success rate (14 patients) when a “proximal” response was obtained (32 patients). However, this suggests that a practitioner using this same technique can expect an overall success rate of a more modest 86% (129 successes in 150 patients). The authors “accepted” what they labeled “proximal” responses because it was part of their study protocol. Obviously, practitioners aware of this information would not choose to accept a proximal response as an endpoint, and would attempt to stimulate a distal contraction. However, in our experience using a different approach to the brachial plexus cords (2,3) , eliciting a distal response is not always possible. Therefore, we are very interested to learn what the authors’ experience has been using this technique when not abiding by their study protocol of accepting any muscle contraction distal to the deltoid. Only with this additional information can practitioners calculate the success rate that they may expect using the technique described by the authors. Additionally, in their Methods section, the authors indicate that they considered contraction of the flexor carpi radialis and ulnaris to be a “proximal” contraction. However, immediately following this, they state that the contraction was considered to be “distal if flexion or extension of the wrist or the fingers was obtained.” The tendon of the flexor carpi radialis runs through the flexor retinaculum and inserts into the bases of the second and third metacarpals. The tendon of the flexor carpi ulnaris inserts into the pisiform, and via two ligaments, into the hamate and fifth metacarpal. Therefore, Brian M. Ilfeld, MD F. Kayser Enneking, MD Anesthesia & Analgesia: September 2002 - Volume 95 - Issue 3 - p 784 doi: 10.1213/00000539-200209000-00058 LETTERS TO THE EDITOR: Letters & Announcements Brachial Plexus Infraclavicular Block Success Rate and Appropriate Endpoints Ilfeld, Brian M. MD; Kayser Enneking, F. MD Department of Anesthesiology University of Florida, College of Medicine Gainesville, FL