The presence of transverse cervical and dorsal scapular arteries at three ultrasound probe positions commonly used in supraclavicular brachial plexus blockade.
ABSTRACT Ultrasound-guided supraclavicular brachial plexus block carries a risk for puncture of vascular structures. In this study, we determined the frequency with which the transverse cervical artery (TCA) and the dorsal scapular artery (DSA) are detected by ultrasound evaluation at 3 probe positions during supraclavicular block.
Ultrasound examinations of the supraclavicular region were performed in 53 healthy adult volunteers. Ultrasound images of the supraclavicular region were acquired at 3 probe positions: position A (the brachial plexus and the subclavian artery both lying on the first rib); position B (the brachial plexus on the first rib; the artery on the pleura); and position C (the brachial plexus between the anterior and middle scalene muscles). The primary outcome variables were the frequencies with which TCA and DSA were detected by 2-dimensional and color Doppler imaging at 3 specified probe positions.
One hundred six supraclavicular regions were examined in 53 subjects. The subclavian artery was detected in all subjects. TCA was more often detected than DSA, 94 (88.7%, 95% confidence interval [CI] 80.7%-93.8%) and 36 (34%, 95% CI 25.3%-43.9%) of 106 scans, respectively (McNemar P value <0.001). TCA was detected in 2 (1.9%, 95% CI 0.3%-7.3%), 31 (29.2%, 95% CI 20.9%-38.9%), and 61 (57.5%, 95% CI 47.5%-66.9%) of scans at probe positions A, B, and C, respectively, whereas DSA was detected in 3 (2.8%, 95% CI 0.7%-8.6%), 23 (21.7%, 95% CI 14.5%-30.9%), and 10 (9.4%, 95% CI 4.8%-17.0%) of scans at probe positions A, B, and C, respectively. Thus, the TCA and DSA were less likely to be present with probe position A (all P < 0.001).
TCA was more often detected than DSA in the vicinity of the brachial plexus in the supraclavicular region. Both TCA and DSA were least likely to be present in probe position A. Color Doppler, particularly for probe position A, may help to reduce the risk for inadvertent vascular puncture during ultrasound-guided supraclavicular block.
- Regional anesthesia and pain medicine 01/2011; 36(4):412-3. · 4.16 Impact Factor
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ABSTRACT: The use of ultrasound (US) for localization of neural structures allows real-time visualization of anatomy; however, variability in the arrangement of structures has been observed. The impact of these variations on the performance and outcome of regional anesthetic techniques remains unclear. We discuss possible anatomic explanations and correlation with clinical observations. We report limited spread of local anesthetic observed during the performance of a US-guided interscalene block. This was associated with an anomalous vessel arising from the subclavian artery, which effectively divided the brachial plexus into 2 compartments. Spread of local anesthetic was restricted to the upper compartment around the C5 through C7 nerve roots. There was no anesthetic fluid visualized in the lower compartment. This produced a block that provided surgical anesthesia for shoulder arthroscopy as well as excellent postoperative analgesia, although the medial and distal aspects of the arm remained unaffected. This case illustrates the ability of US to identify anatomic variations and their relevance to the performance of regional anesthetic techniques.Regional anesthesia and pain medicine 01/2008; 33(4):357-9. · 4.16 Impact Factor
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ABSTRACT: In this study, we evaluated state-of-the-art ultrasound technology for supraclavicular brachial plexus blocks in 40 outpatients. Ultrasound imaging was used to identify the brachial plexus before the block, guide the block needle to reach target nerves, and visualize the pattern of local anesthetic spread. Needle position was further confirmed by nerve stimulation before injection. The block technique we describe aligned the needle path with the ultrasound beam. The block was successful after one attempt in 95% of the cases, with one failure attributable to subcutaneous injection and one to partial intravascular injection. Pneumothorax did not occur. Our preliminary data suggest that a high-resolution ultrasound probe can reliably identify the brachial plexus and its neighboring structures in the supraclavicular region. The technique of real-time guidance during needle advancement can quickly localize nerves. Distinct patterns of local anesthetic spread observed on ultrasound can further confirm accurate needle location. IMPLICATIONS: Real-time ultrasound imaging during supraclavicular brachial plexus blocks can facilitate nerve localization and needle placement and examine the pattern of local anesthetic spread.Anesthesia & Analgesia 11/2003; 97(5):1514-7. · 3.30 Impact Factor