Brachial plexus blocks at the interscalene level are frequently chosen by physicians and recommended by textbooks for providing regional anesthesia and analgesia to patients scheduled for shoulder surgery. Published data concerning interscalene single-injection or continuous brachial plexus blocks report good analgesic effects. The principle of interscalene catheters is to extend analgesia beyond the duration of the local anesthetic's effect through continuous infusion, as opposed to a single injection. However, in addition to the recognized beneficial effects of interscalene blocks, whether administered as a single injection or through a catheter, there have been reports of consequences ranging from minor side effects to severe, life-threatening complications. Both can be simply explained by direct mispuncture, as well as undesired local anesthetic spread or misplaced catheters. In particular, catheters pose a high risk when advanced or placed uncontrollably, a fact confirmed by reports of fatal outcomes. Secondary catheter dislocations explain side effects or loss of effectiveness that may occur hours or days after the initial correct function has been observed. From an anatomical and physiological perspective, this appears logical: the catheter tip must be placed near the plexus in an anatomically tight and confined space. Thus, the catheter's position may be altered with the movement of the neck or shoulder, e.g., during physiotherapy. The safe use of interscalene catheters is therefore a balance between high analgesia quality and the control of side effects and complications, much like the passage between Scylla and Charybdis. We are convinced that the anatomical basis crucial for the brachial plexus block procedure at the interscalene level is not sufficiently depicted in the common regional anesthesia literature or textbooks. We would like to provide a comprehensive anatomical survey of the lateral neck, with special attention paid to the safe placement of interscalene catheters.

Neben der Therapie bei komplexem regionalen Schmerzsyndrom (CRPS) ist die Ganglion-stellatum-Blockade eine Behandlungsoption bei refraktären intermittierenden ventrikulären Tachykardien (VT). Trotz Verwendung bildgebender Techniken wie der Fluoroskopie oder Sonographie ist eine Vielzahl von Nebenwirkungen oder Komplikationen berichtet. Diese sind auf den komplexen anatomischen Situs sowie die injizierten Lokalanästhetika(LA)-Volumina zurückzuführen. Es wird über die Katheteranlage zur kontinuierlichen Blockade des zervikalen Truncus sympathicus (TS) mittels hochauflösender Ultraschallbildgebung (HRUI) bei einem Patienten mit intermittierenden VT berichtet. Die Kanülenspitze wurde am TS auf der Vorderseite des M. longus colli platziert, und 20 mg Prilocain, 1

Die Anlage einer peripheren Venenverweilkanüle ist eine invasive Routinemaßnahme, deren Komplikationen häufig unterschätzt werden. Bei schwierigen Venenverhältnissen sind häufig mehrere Punktionsversuche erforderlich, die zeitaufwendig, für Patienten unnötig schmerzhaft und trotzdem nicht immer erfolgreich sind. Durch die enge anatomische Lagebeziehung von Venen und Nerven am Arm sind punktionsbedingte Nervenschäden keine Seltenheit. Trotz noch limitierter Datenlage konnte gezeigt werden, dass sonographisch geführte periphere Venenpunktionen der traditionellen Landmarkentechnik in Bezug auf Erfolgsraten, Zeitersparnis, Komplikationsvermeidung und Patientenzufriedenheit überlegen sind. Um die sonographische Punktionstechnik für Gefäßzugänge erfolgreich in Routineabläufe zu integrieren, ist eine strukturierte Aus- und Weiterbildung Voraussetzung. Diese muss sowohl anatomische Kenntnisse, Kenntnisse der Ultraschallbildgebung und Training der sonographischen Nadelführungstechniken beinhalten.

Zusammenfassung Die Sonografie ist eine hochgradig vom Anwender abhangige Technik. Sie setzt ein erhebliches Ma ss an sonoanatomischen und sonografischen Kenntnissen voraus und verlangt gute Fertigkeiten des Untersuchers. Sie ermoglicht die Identifikation des Punktionsziels, die Beobachtung des Kanulenvorschubs und Beurteilung des Ausbreitungsmusters des Lokalanasthetikums in Echtzeit. Diese Vorteile kann die PNS nicht im selben Ma ss e bieten, sie kann aber die Nervenlokalisation unter schwierigen sonografischen Verhaltnissen ermoglichen. Die Kombinationen beider Lokalisierungstechniken ist in der praktischen Umsetzung komplex. Teilweise wird die eine Technik durch die Kombination mit der zweiten sogar erschwert. Die Stimulation parallel zur Sonografie dient in 1. Linie als Warntechnik bei nicht sichtbarer Kanulenspitze. Sie sollte nicht als Kompensationstechnik fur mangelnde sonografische Fertigkeiten und Kenntnisse verstanden werden. Sie kann jedoch hilfreich im Sinne eines Bridging sein, sofern sich der Anwender der Limitationen der Technik bewusst ist.Abstract Sonography is a highly user-dependent technology. It presupposes a considerable degree of sonoanatomic and sonographic knowledge and requires good practical skills of the examiner. Sonography allows the identification of the puncture target, observes the needle feed and assesses the spread pattern of the local anesthetic in real time. Peripheral electrical nerve stimulation (PNS) cannot offer these advantages to the same degree, but may allow nerve localization under difficult sonographic conditions. The combination of the two locating techniques is complex in its practical implementation. Partially, the use of one location technique is made even more difficult by the combination with the second. PNS in parallel to sonography serves primarily as a warning technology in the case of an invisible cannula tip. It should not be construed as a compensation technique for the lack of sonographic skills or knowledge. However, PNS may be helpful in the sense of a bridging technology as long as the user is aware of its limitations.

The objective of this prospective, randomised study was to examine the impact of a multi-angle needle guide for ultrasound-guided, in-plane, central venous catheter placement in the subclavian vein. One hundred and sixty patients were randomly allocated to two groups, freehand or needle-guided, and then 159 catheterisations were analysed. Cannulation of the first examined access site was successful in 96.9% of cases with no significant difference between groups. There were three arterial punctures and no other severe injuries. Catheter misplacements did not differ between the groups. Higher success rates within the first and second attempts in the needle-guided group were observed (p = 0.041 and p = 0.019, respectively). Use of the needle guide reduced the access time from a median (IQR [range]) of 30 (18-76 [6-1409]) s to 16 (10-30 [4-295]) s; p = 0.0001, and increased needle visibility from 31.8% (9.7%-52.2% [0-96.67]) to 86.2% (62.5%-100% [0-100]); p < 0.0001. A multi-angle needle guide significantly improved aligning the needle and ultrasound plane compared with the freehand technique when cannulating the subclavian vein. Use of the guide resulted in faster access times and increased success at the first and second attempts.

Background Although intima-media thickness (IMT) was increased in several inflammatory diseases, studies investigating whether the inflammatory processes lead to macrovascular alteration with increased IMT in complex regional pain syndrome (CRPS) lack. Methods Using ultrasound (high-resolution B-mode), we compared bilaterally the IMT of the common carotid artery (CCA-IMT), the radial artery (RA-IMT), the brachial artery (BRA-IMT) and the quotient Q RA/CCA , in CRPS type I (n=17), peripheral nerve injury (PNI, n=17) and pain-free controls (PFC, n=22, matched to CRPS by gender, age and traditional cardiovascular risk factors). Statistics: Spearman’s correlation, paired t-test, ANOVA (p<0.05). Results Compared to PFC, RA-IMT were significantly increased in both patient groups bilaterally (mean±standard deviation, CRPS affected side vs. PFC dominant side: 0.32±0.08 mm vs. 0.19±0.08 mm, p<0.001; PNI affected side vs. PFC dominant side: 0.27±0.09 mm vs. 0.19±0.08 mm, p< 0.05; CRPS non-affected side vs. PFC non-dominant side: 0.30±0.10 mm vs. 0.19±0.09 mm, p<0.001; PNI non-affected side vs. PFC non-dominant side: 0.25±0.10 mm vs. 0.19±0.09 mm, p<0.05) and Q RA/CCA (CRPS affected-side vs. PFC dominant side: 0.49±0.12 vs. 0.30±0.11, p<0.001; PNI affected side vs. PFC dominant side: 0.41±0.10 vs. 0.30±0.11, p<0.05; CRPS non-affected side vs. PFC non-dominant side: 0.43±0.19 vs. 0.30±0.13, p<0.001; PNI non-affected side vs. PFC non-dominant side: 0.39±0.14 vs. 0.30±0.13, p<0.05), and BRA-IMT - only on the affected side in CRPS (CRPS: 0.42±0.06 mm vs. PFC: 0.35±0.08 mm; p<0.05). In CRPS, Q RA/CCA was significantly higher on the affected side compared to PNI (p<0.05). However, only CRPS displayed within-group side-to-side differences with a significantly increased RA-IMT and Q RA/CCA on the affected side (p<0.05). The CCA-IMT was comparable between all groups and sides. Conclusions The increased IMT of peripheral arteries in CRPS suggests ongoing inflammatory process. Until now, only endothelial dysfunction has been reported. The presented morphological macrovascular alterations might explain the treatment resistance of some CRPS patients.

Background and objective For cannulation of the internal jugular vein (IJV), ultrasound increases the number of first pass successes and reduces the rate of mechanical complications. A frequent complication of IJV access is the accidental injury of the common carotid artery (CCA), which can be dangerous in some circumstances. Landmarks and palpation of the CCA are used when ultrasound is not available. These conventional methods are based on the lateral position of the IJV to the CCA, and physicians traditionally employ head rotation to increase the success rates of IJV cannulation. Ultrasound scanning strictly from the anterior to posterior is not possible for this process because the probe must be adequately coupled to compensate for the curvature of the neck. Scans have been performed from different angles lateral to the neck, but misleadingly depict the relationship of the IJV to the CCA. In this study, the authors examined the effect of scanning at a 45° angle at the level of the cricoid on the depiction of the IJV in relation to the CCA. Furthermore, the influence of 30° head rotation to the contralateral side was also investigated. Method The relationship of the IJV to the CCA was recorded using ultrasound in 600 patients. Patients were placed in a supine position and the probe was coupled at the level of the cricoid, scanning at an angle of 45° from the lateral side of the neck. Based on the ultrasound images, the position of the IJV in relation to the CCA was recorded using a segmented grid. The centre of the vein (cross-section of the vertical and longitudinal diameter) determined the segment classification, in which the top of the ultrasound image was defined as the anterior. Additionally, in 300 patients, the head was rotated to the contralateral side at 30° to examine the impact of head rotation on the position of the IJV. Results The IJV was found in the lateral segment in only 3.0–3.3% of the patients. It was found in the anteromedial segment more frequently on the left side compared to the right side (P < 0.005). On the right side, the IJV was shown more frequently in the anterolateral position (P < 0.0001). Head rotation at 30° in 300 of the 600 patients caused a significant change of the IJV position in the left anteromedial segment, in that it frequently placed the IJV towards the anterior and anterolateral segment (P < 0.05). There was no significant impact of head rotation on the IJV representation on the right side. Atypical positions of the IJV (posterior, medial or thrombosis) were found in some cases. Conclusion Ultrasound images used for IJV access usually depict the vein as being anterior to the CCA and only to a minor extent in the lateral position. This positioning is important for needle processing in order to avoid accidental arterial puncture and to identify atypical positions of the IJV. To determine the ideal puncture site, images of the neck vessels along their entire pathway should be obtained when using ultrasound for vascular access.

Background and Objectives: Needle visibility is a crucial requirement for successful and safe ultrasound-guided peripheral nerve blocks. We performed a prospective study on the ultrasonic imaging quality of various commercially available needles. We tested the hypothesis that different nerve block needles would have different ultrasonic appearances. Furthermore, we examined the influence of needle angle with regard to the ultrasound plane, 2 types of media surrounding the needle, and the impact of 3 different ultrasound machines.Methods: Twelve needles were prospectively tested for 3 ultrasound planes (longitudinal, axial tip, and axial sbaft) at 2 different angles (0 degrees and 45 degrees). Quality of needle visibility and ultrasound scans were described by using 6 criteria (visibility score range 0-10): (1) visibility of needle; (2) visibility of surrounding media; (3) consistency of needle surface; (4) formation of artifacts; (5) degree of shadowing; and (6) detection and distinction of the needle from the surrounding media. Additionally, every ultrasound scan was performed in 2 media (water bath and animal model) with 3 ultrasound devices and evaluated by 2 investigators. Evaluation of the ultrasound scans was blinded with regard to needle but not to the ultrasound machine and media.Results: in the animal model, visibility was good at 0 degrees (visibility score greater than 6) but was decreased for all needles at a 45 degree angle (criterion 6). In this setting, 2 needles were difficult to identify (score less than 3; criterion 6) and only 3 of 12 reached a score of 7 or more (criterion 6). Depiction quality for all 3 planes was significantly lower in the animal model when compared with the water bath (P <.001) and at an angle of 45 degrees when compared with 0 degrees (P <.001). There was no significant impact of the ultrasound machine on image quality.Conclusions: in a tissue-equivalent model we found significant differences among different types of needles at a 45 degree angle. In clinical use, angles between 30 degrees and 60 degrees are required. Because visibility of the needle is a keystone of ultrasound-guided peripheral nerve blocks, our results suggest the need to optimize the echogenicity of needles used for ultrasound-guided nerve blocks.

Physicians spend a considerable amount of time and effort inserting catheters and needles into patients. Central venous catheters are the mainstay of measuring hemodynamic variables that cannot be assessed by noninvasive procedures. These catheters also allow hemodialysis, parenteral nutritional support, delivery of medications, and catecholamine administration. Arterial pressure catheters are frequently used for hemodynamic monitoring and for obtaining arterial blood gases in critically ill patients. Such use of arterial and central venous catheters, however, is potentially associated with severe complications that can be injurious to patients and expensive to treat. Techniques involving the use of anatomic landmarks have been the traditional mainstay of accessing the central venous system for decades. With the development and refinement of portable and affordable high-resolution ultrasound devices, imaging vascular access has changed the role of the traditional landmark techniques. In this article, we explain the use of ultrasound for vascular access to reduce complications associated with cannulation of veins and arteries. We will also provide a brief overview of the current literature regarding ultrasound-guided vascular access.