Risks and Benefits of Ultrasound, Nerve Stimulation, and Their Combination for Guiding Peripheral Nerve Blocks: A Retrospective Registry Analysis.

BACKGROUND: Ultrasound, nerve stimulation, and their combination are all considered acceptable ways to guide peripheral nerve blocks. Which approach is most effective and associated with the fewest complications is unknown. We therefore used a large registry to analyze whether there are differences in vascular punctures, multiple skin punctures, and unintended paresthesia. METHODS: Twenty-six thousand seven hundred and thirty-three cases were extracted from the 25-center German Network for Regional Anesthesia registry between 2007 and 2016 and grouped into ultrasound-guided puncture (n = 10,380), ultrasound combined with nerve stimulation (n=8173), and nerve stimulation alone (n = 8180). The primary outcomes of vascular puncture, multiple skin punctures, and unintended paresthesia during insertion were compared with conditional logistic regression after 1:1:1 propensity score matching. Results are presented as odds ratios and 95% CIs. RESULTS: Propensity matching successfully paired 2508 patients with ultrasound alone (24% of 10,380 patients), 2508 patients with a combination of ultrasound/nerve stimulation (31% of 8173 patients), and 2508 patients with nerve stimulation alone (31% of 8180 patients). After matching, no variable was imbalanced (standardized differences <0.1). Compared with ultrasound guidance alone, the odds of multiple skin punctures (2.2 [1.7-2.8]; P < .001) and vascular puncture (2.7 [1.6-4.5]; P < .001) were higher with nerve stimulation alone, and the odds for unintended paresthesia were lower with nerve stimulation alone (0.3 [0.1-0.7]; P = .03). The combined use of ultrasound/nerve stimulation showed higher odds of multiple skin punctures (1.5 [1.2-1.9]; P = .001) and lower odds of unintended paresthesia (0.4 [0.2-0.8]; P = .007) compared with ultrasound alone. Comparing the combined use of ultrasound/nerve stimulation with ultrasound alone, the odds for vascular puncture (1.3 [0.7-2.2]; P = .4) did not differ significantly. Systemic toxicity of local anesthetics was not observed in any patient with ultrasound guidance alone, in 1 patient with the combined use of ultrasound and nerve stimulation, and in 1 patient with nerve stimulation alone. CONCLUSIONS: Use of ultrasound alone reduced the odds of vascular and multiple skin punctures. However, the sole use of ultrasound increases the odds of paresthesia.

[Peripheral Regional Anesthesia Without Any Complications - a Dream Comes True?!] / Periphere Regionalanästhesie ohne Komplikationen ­ Ein Traum wird wahr?!

Peripheral regional anesthesia procedures, such as femoral nerve block, are relatively safe procedures in clinical anesthesia. Nevertheless, it may lead to typical, usually transient and rarely even persistent complications. This article aims to highlight key aspects of complications in peripheral regional anesthesia and, in particular, strategies to reduce risk. Moreover, beside general complications, which might potentially occur in any peripheral nerve blockade ("bleeding/infection/nerve damage"), accidental co-blockades of other nerval structures are discussed using the example of the brachial plexus. In addition to the presentation of the possible complications, this article discusses improvements in the techniques during the last two decades. Due to the use of ultrasound, some side effects nowadays are supposed to occur less likely. An outlook into the future will inform the reader about improved or more selective blockages.

DEGUM Recommendations on Infection Prevention in Ultrasound and Endoscopic Ultrasound.

Microbial contamination of ultrasound probes for percutaneous or endoscopic use is common. However, infectious diseases caused by transmission of microorganisms by US procedures have rarely been reported. In Germany, legal regulations address hygiene in ultrasound procedures. Based on these regulations and the available literature, an expert panel of the German Society of Ultrasound in Medicine (DEGUM) has formulated sophisticated recommendations on hygienic measures in percutaneous and endoscopic US, including US-guided interventions.

Prolonged Catheter Use and Infection in Regional Anesthesia: A Retrospective Registry Analysis.

BACKGROUND: Prolonged catheter use is controversial because of the risk of catheter-related infection, but the extent to which the risk increases over time remains unknown. We thus assessed the time-dependence of catheter-related infection risk up to 15 days. METHODS: Our analysis was based on the German Network for Regional Anesthesia, which includes 25 centers. We considered 44,555 patients who had surgery between 2007 and 2014 and had continuous regional anesthesia as well as complete covariable details. Cox regression analysis was performed and adjusted for confounding covariables to examine the relationship between catheter duration and probability of infection-free catheter use. RESULTS: After adjustment for confounding factors, the probability of infection-free catheter use decreases with each day of peripheral and epidural catheter use. In peripheral catheters, it was 99% at day 4 of catheter duration, 96% at day 7, and 73% at day 15. In epidural catheters, it was 99% at day 4 of catheter duration, 95% at day 7, and 73% at day 15. Only 31 patients (0.07%) had severe infections that prompted surgical intervention. Among these were five catheters that initially had only mild or moderate signs of infection and were left in situ; all progressed to severe infections. CONCLUSIONS: Infection risk in catheter use increases over time, especially after four days. Infected catheters should be removed as soon as practical. VISUAL ABSTRACT: An online visual overview is available for this article at http://links.lww.com/ALN/B683.

Psoas Versus Femoral Blocks: A Registry Analysis of Risks and Benefits.

BACKGROUND AND OBJECTIVES: Psoas blocks are an alternative to femoral nerve blocks and have the potential advantage of blocking the entire lumbar plexus. However, the psoas muscle is located deeply, making psoas blocks more difficult than femoral blocks. In contrast, while femoral blocks are generally easy to perform, the inguinal region is prone to infection. We thus tested the hypothesis that psoas blocks are associated with more insertion-related complications than femoral blocks but have fewer catheter-related infections. METHODS: We extracted 22,434 surgical cases from the German Network for Regional Anesthesia registry (2007-2014) and grouped cases as psoas (n = 7593) and femoral (n = 14,841) blocks. Insertion-related complications (including single-shot blocks and catheter) and infectious complications (including only catheter) in each group were compared with χ tests. The groups were compared with multivariable logistic models, adjusted for potential confounding factors. RESULTS: After adjustment for potential confounding factors, psoas blocks were associated with more complications than femoral blocks including vascular puncture 6.3% versus 1.1%, with an adjusted odds ratio (aOR) of 3.6 (95% confidence interval [CI], 2.9-4.6; P < 0.001), and multiple skin punctures 12.6% versus 7.7%, with an aOR of 2.6 (95% CI, 2.1-3.3; P <0.001). Psoas blocks were also associated with fewer catheter-related infections: 0.3% versus 0.9% (aOR of 0.4; 95% CI, 0.2-0.8; P = 0.016), and with improved patient satisfaction (mean ± SD 0- to 10-point scale score, 9.6 ± 1.2 vs 8.4 ± 2.9; P < 0.001). Results from a propensity-matched sensitivity analysis were similar. CONCLUSIONS: Psoas blocks are associated with more insertion-related complications but fewer infectious complications. CLINICAL TRIAL REGISTRATION: ID NCT02846610.

[Regional anaesthesia in patients with lower limb injury]. / Anästhesie in der Orthopädie†/Unfallchirurgie - Regionalanästhesie bei Verletzungen der unteren Extremität.

Almost all surgical procedures following injury can be provided in peripheral regional anaesthesia or spinal anaesthesia - under consideration of specific contraindications. The majority of injuries at the lower limb are associated with severe pain and immobilization during the postoperative phase. Moreover, opioids are often required which are related to nausea, vomiting and impairment of vigilance. For avoidance of those side effects, regional anaesthesia techniques should be considered as a more effective approach with a better profile of side effects. Hip and proximal femur fractures are more frequent in elder patients with a corresponding high morbidity. Therefore anaesthesia is challenging in those patients. Even injuries of the long bones - like the femur and the tibia - are causing severe pain, therefore an appropriate concept for acute pain therapy is required. Moreover, for injuries with affection of bony joint-structures (i. e. knee, ankle, calcaneus) and marked soft-tissue injuries continuous regional anaesthesia techniques could provide advantages during acute pain therapy.

[Regional anaesthesia in injuries of the upper extremity]. / Anästhesie in der Orthopädie†/Unfallchirurgie - Regionalanästhesie bei Verletzungen der oberen Extremität.

Regional anaesthesia has significant advantages compared to general anaesthesia with an opiate-based postoperative analgesia in injuries of the upper extremity. Severe pain may be considered a risk factor for the development of chronic postoperative pain syndromes in adults and children. Depending on the anticipated postoperative pain level, a catheter procedure should be used. Fractures of the upper extremity are common and may also be associated with seemingly minor injuries with a high postoperative pain level. Nerve damage can be caused mainly by traumatic fractures, or iatrogenically during surgical procedures. Reduced possible neurological evaluability should not prevent the excellent pain control which regional anesthesia can provide. Since the brachial plexus is predominantly responsible for the sensory innervation of the entire upper extremity, therefore all known block techniques in regional anaesthesia apply. Since the introduction of ultrasound in regional anaesthesia (USGRA), older methods like the supraclavicular approach, which were previously banned due to high complication rates, are now being rediscovered. Both new and old blockade methods are much more effective and safe with ultrasound support because of the rapid visualization of the anatomy and needle.

[The DGAI training module 3 in anaesthetic focussed sonography: neurosonography]. / DGAI-zertifizierte Seminarreihe Anästhesie Fokussierte Sonografie - Modul 3: Neurosonografie.

Identification of the right puncture site and the target structures are mandatory in performing nerve blocks. Ultrasound is a new method, that visualizes target structures as well as the injection and spread of local anaesthetic solution. The presented module 3 neurosonography is part of the didactic concept "anaesthesiology focussed sonography" developed by the german society of anaesthesiology and intensive care. It contains all essential nerve blocks of the upper and lower limb. Additionally the structural requirements to provide the course are included.