Ultrasound Mapping of Stimulated Finger Flexion During Infra-Clavicular Brachial Plexus Nerve Blockade for Elbow Arthroplasty and Its Correlation To Postoperative Analgesia

Background: Infraclavicular brachial plexus nerve blockade (ICNB) is a very common anesthetic procedure performed for upper extremity surgery at the elbow and distally, however the rate of adequate analgesia is variable among patients. Ultrasound guidance (US) has not been demonstrated to increase the success rate of ICNB when compared to nerve stimulator (NS) guidance. Combined US and NS guided ICNB have not been reported, although there is a call for more trials comparing the two techniques. This study was performed to observe if a specific anatomic region near the axillary artery of the brachial plexus identified by finger flexion with nerve stimulation results in improved postoperative analgesia. Method: Patients undergoing elective elbow arthroplasty received a postoperative ICNB. The angle of the nerve stimulator needle tip and the radial distance from the center of the arterial lumen at which an optimal finger flexion twitch response was observed were measured with ultrasound imaging. Pain scores and postoperative opioid dosages on discharge from the post anesthesia care unit and at 24 hours after surgery were recorded. Results: 11 patients enrolled in this study. Adequate finger flexion response to nerve stimulation that resulted in complete analgesia was more frequently observed when the needle was located in the postero-superior quadrant in relation to the axillary artery. Identifying a specific point near the brachial plexus in relation to the artery that consistently provides superior analgesia is desirable and would lead to improved analgesia and faster onset time of nerve blockade and would reduce the need for other approaches for brachial plexus blockade with their associated disadvantages.

Ultrasound Mapping of Nerve Stimulator Response during Sciatic Nerve Blockade and Relation to Postoperative Pain Scores

1.1 Background and Purpose: Ultrasound guided sciatic nerve blockade has rapid onset but at 24 hours pain is greater than nerve stimulator techniques. Injection of the nerve branches or trunk and sub-sheath blockade increase success and reduce onset times but risk injury. This study mapped needle coordinates for sciatic nerve blockade with nerve stimulation and its relation to postoperative pain scores. 1.2 Method: Angle and distance of the needle tip and infusion catheter from the popliteal sciatic nerve at which stimulated plantar flexion occurred were measured. Pain scores at postanesthesia unit discharge and 24 hours were recorded. 1.3 Results: 81% of opioid naïve patients reported immediate analgesia and 20.8% at 24 hours. In opioid tolerant patients 56.8% reported immediate analgesia and 9.1% at 24 hours. Plantar flexion was observed with the needle in the posterior medial quadrant near the sciatic nerve. Opioid tolerant patients reported adequate analgesia when the needle was located more medially and proximally to the sciatic nerve. 1.4 Conclusion: Stimulated plantar flexion is isolated to a narrow angular range in the posterior medial quadrant adjacent to the sciatic nerve. Opioid tolerant patients report adequate analgesia if the needle and catheter are more medial and proximal to the nerve surface.

Patient Variability in Sciatic Nerve Branch Point Distance Using Ultrasound Guided Localization

Background and Objectives: Improved ultrasound and needle technology make popliteal sciatic nerve blockade a popular anesthetic technique and imaging to localize the branch point of the common peroneal and posterior tibial components is important because successful blockade techniques vary with respect to injection of the common trunk proximally or separate injections distally. Nerve stimulation, ultrasound, cadaveric and magnetic resonance studies demonstrate variability in distance and discordance between imaging and anatomic examination of the branch point. The popliteal crease and imprecise, inaccessible landmarks render measurement of the branch point variable and inaccurate. The purpose of this study was to use the tibial tuberosity, a fixed bony reference, to measure the distance of the branch point. Method: During popliteal sciatic nerve blockade in the supine position the branch point was identified by ultrasound and the block needle was inserted. The vertical distance from the tibial tuberosity prominence and needle insertion point was measured. Results: In 92 patients the branch point is a mean distance of 12.91 cm proximal to the tibial tuberosity and more proximal in male (13.74 cm) than female patients (12.08 cm). Body height is related to the branch point distance and is more proximal in taller patients. Separation into two nerve branches during local anesthetic injection supports notions of more proximal neural anatomic division. Limitations: Imaging of the sciatic nerve division may not equal its true anatomic separation. Conclusion: Refinements in identification and resolution of the anatomic division of the nerve branch point will determine if more accurate localization is of any clinical significance for successful nerve blockade.

Ultrasound Guided lateral Infra-trochanteric Sciatic Nerve Blockade for Proximal Tibial Surgery: A Novel Technique

Sciatic nerve blockade (SNB) can be performed at several point along its anatomic course. Proximal SNB techniques described include the classic Labat, sacral (Mansur), infragluteal (Raj), and anterior approches Distal SNB techniques include the mid-femoral, posterior and lateral popliteal and mid-tibial approaches. The anatomic region of the lower extramity to be anesthetixzed will determine the appropriate SNB technique to use for the operative procedure.

Abstract Title: Ultrasound Guided Trans-sartorial Continuous Saphenous Nerve Blockade - A technique for Relief of Postoperative Medial Incisional Foot and Ankle Pain

The saphenous nerve (SaN) innervates the region from the upper medial thigh to the medial aspect of the foot and ankle. A femoral nerve block (FNB) is effective for blockade of the SaN but this causes quadriceps weekness and reduced patient mobility that is unsuitable in an ambulatory surgical setting.