[Common and New Regional Anaesthesia Techniques Under Review - From Head to Abdomen]. / Alte und neue Regionalanästhesieverfahren unter Review ­ Kopf bis Bauch.

By implementation of sonography regional anesthesia became more relevant in the daily practice of anesthesia and pain therapy. Due to visualized needle guidance ultrasound supports more safety during needle placement. Thereby new truncal blocks got enabled. Next to the blocking of specific nerve structures, plane blocks got established which can also be described as interfascial compartment blocks. The present review illustrates published and established blocks in daily practice concerning indications and the procedural issues. Moreover, the authors explain potential risks, complications and dosing of local anesthetics.

[Peripheral Regional Anesthesia Techniques - Standards in Flux?!] / Periphere Regionalanästhesieverfahren ­ Standards im Wandel?!

This review article provides an overview of current developments in peripheral regional anaesthesia (RA). The authors present a subjective compilation based on discussions at professional events and inquiries to the Working Group on Regional Anaesthesia of the German Society for Anaesthesiology and Intensive Care Medicine (DGAI). The article addresses several relevant topics, including the handling of antithrombotic medication in peripheral blockades with reference to European guidelines, the debate on the discharge timing after plexus anaesthesia, and the consideration of rebound pain as an independent pain entity following RA.Furthermore, the contentious discussion regarding the administration of peripheral nerve blockades under general anaesthesia is illuminated. The authors express no fundamental concerns in this regard but emphasize the importance of preoperative evaluation and individual patient needs. The question of mixing local anaesthetics is also addressed, with the authors critically questioning this tradition and recommending the use of individual, long-acting substances.Another focal point is the application of peripheral nerve blockades in emergency medicine, both in preclinical and emergency room settings. The authors highlight the necessity for high-quality studies and discuss the complex organizational issues associated with the preclinical application of RA techniques.

Nominal logistic regression analysis of variables determining needle visibility in ultrasound images - a full factorial cadaver study.

BACKGROUND: Needle visualization is essential to avoid vascular puncture and nerve injury in ultrasound-guided regional anesthesia. Several factors that statistically influence needle visibility have been described but the dimensions of their individual impact remain unclear. This study aimed to quantify the impact of various independent factors on ultrasound needle visibility. METHODS: A total of 1500 ultrasound videos of in-plane needle insertions were obtained in embalmed cadavers with ten different commercially available echogenic and non-echogenic needles at different insertion angles and bevel orientations in a full factorial study design. The visibility of needle tip and shaft were rated as "good" or "poor" visibility. Nominal logistic regression analyses were calculated for the visibility of the needle tip and shaft. RESULTS: SonoPlex Stim Sprotte, SonoTAP Facet (needle tip and shaft) and Spinostar PencilPoint (needle tip)), insertion angle and bevel orientation were associated with good ultrasound visibility, reaching statistical significance (p < 0.05). The range of the effect on the log-odds scale for needle tip visibility was largest for the insertion angle with 6.33, followed by the tissue condition (3.76), bevel orientation (1.45) and the needle types (1.25). Regarding the needle shaft visibility, the largest effect range was observed with the insertion angle (7.36), followed by the tissue conditions with 3.96, needle type (1.86) and bevel orientation (0.95). CONCLUSION: In-plane needle visibility in ultrasound images depends mainly on the insertion angle, as expected. This is closely followed by the tissue condition, which is a factor related to the patient, thus cannot be altered to improve needle visibility. In the dimensions of the log-odds scale, the choice of a specific needle is far less important towards achieving a good visualization, whereas optimizing the bevel orientation can have a larger impact than the needle choice. Concluding from the relative dimensions of factors that determine needle visibility in this model, the importance of needles with echogenic features may be overrated.

Intraoperative management of combined general anesthesia and thoracic epidural analgesia: A survey among German anesthetists.

BACKGROUND: Evidence concerning combined general anesthesia (GA) and thoracic epidural analgesia (EA) is controversial and the procedure appears heterogeneous in clinical implementation. We aimed to gain an overview of different approaches and to unveil a suspected heterogeneity concerning the intraoperative management of combined GA and EA. METHODS: This was an anonymous survey among Members of the Scientific working group for regional anesthesia within the German Society of Anaesthesiology and Intensive Care Medicine (DGAI) conducted from February 2020 to August 2020. RESULTS: The response rate was 38%. The majority of participants were experienced anesthetists with high expertise for the specific regimen of combined GA and EA. Most participants establish EA in the sitting position (94%), prefer early epidural initiation (prior to skin incision: 80%; intraoperative: 14%) and administer ropivacaine (89%) in rather low concentrations (0.2%: 45%; 0.375%: 30%; 0.75%: 15%) mostly with an opioid (84%) in a bolus-based mode (95%). The majority reduce systemic opioid doses intraoperatively if EA works sufficiently (minimal systemic opioids: 58%; analgesia exclusively via EA: 34%). About 85% manage intraoperative EA insufficiency with systemic opioids, 52% try to escalate EA, and only 25% use non-opioids, e.g. intravenous ketamine or lidocaine. CONCLUSIONS: Although, consensus seems to be present for several aspects (patient's position during epidural puncture, main epidural substance, application mode), there is considerable heterogeneity regarding systemic opioids, rescue strategies for insufficient EA, and hemodynamic management, which might explain inconsistent results of previous trials and meta-analyses.

Early detection of intraneural and intravascular injections with real-time injection pressure monitoring in cadavers.

BACKGROUND AND OBJECTIVES: Injection pressure monitoring can help detecting the needle tip position and avoid intraneural injection. However, it shall be measured at the needle tip in order to be accurate and reproducible with any injection system and non operator-dependent. With an innovative system monitoring the injection pressure right at the needle tip we show that it is possible to early detect an intraneural and also an intravascular injection. METHODS: We performed supraclavicular block-like procedures under real-time ultrasound guidance on two fresh cadaver torsos using a sensing needle with an optical fiber pressure sensor within the shaft continuously measuring injection pressure at the needle tip. A total of 45 ultrasound-guided injections were performed (15 perineural, 15 intraneural and 15 intravenous injections). RESULTS: Mean (SD) injection pressure after only 1 mL injected volume was already significantly higher for the intraneural compared to the perineural injections: 70.46 kPa (11.72) vs 8.34 (4.68) kPa; P < .001. Mean (SD) injection pressure at 1 mL injected volume was significantly lower for the intravascular compared to the perineural injections: 1.51 (0.48) vs 8.34 (4.68) kPa; P < .001. CONCLUSIONS: Our results show that injection pressure monitoring at the needle tip has the potential to help identifying an accidental intraneural or intravascular injection at a very early stage.

Nerve detection using optical spectroscopy, an evaluation in four different models: In human and swine, in-vivo, and post mortem.

OBJECTIVE: Identification of peripheral nerve tissue is crucial in both surgery and regional anesthesia. Recently, optical tissue identification methods are presented to facilitate nerve identification in transcutaneous procedures and surgery. Optimization and validation of such techniques require large datasets. The use of alternative models to human in vivo, like human post mortem, or swine may be suitable to test, optimize and validate new optical techniques. However, differences in tissue characteristics and thus optical properties, like oxygen saturation and tissue perfusion are to be expected. This requires a structured comparison between the models. STUDY DESIGN: Comparative observational study. METHODS: Nerve and surrounding tissues in human (in vivo and post mortem) and swine (in vivo and post mortem) were structurally compared macroscopically, histologically, and spectroscopically. Diffuse reflective spectra were acquired (400-1,600 nm) after illumination with a broad band halogen light. An analytical model was used to quantify optical parameters including concentrations of optical absorbers. RESULTS: Several differences were found histologically and in the optical parameters. Histologically nerve and adipose tissue (subcutaneous fat and sliding fat) showed clear similarities between human and swine while human muscle enclosed more adipocytes and endomysial collagen. Optical parameters revealed model dependent differences in concentrations of ß-carotene, water, fat, and oxygen saturation. The similarity between optical parameters is, however, sufficient to yield a strong positive correlation after cross model classification. CONCLUSION: This study shows and discusses similarities and differences in nerve and surrounding tissues between human in vivo and post mortem, and swine in vivo and post mortem; this could support the discussion to use an alternative model to optimize and validate optical techniques for clinical nerve identification. Lasers Surg. Med. 50:253-261, 2018. © 2017 Wiley Periodicals, Inc.

Feasibility and Impact of Focused Intraoperative Transthoracic Echocardiography on Management in Thoracic Surgery Patients: An Observational Study.

OBJECTIVES: Intraoperative focused transthoracic echocardiography (TTE) is feasible and has an effect on the management of hemodynamically unstable surgical patients. Furthermore, in noncardiac thoracic surgery, TTE might provide additional information for hemodynamic treatment. Transthoracic accessibility during thoracic surgical interventions is assumed to be difficult. For patients positioned on their right side, a modified subcostal transthoracic view might be helpful. DESIGN: A prospective observational study. SETTING: Single-center university hospital. PARTICIPANTS: The study comprised 105 consecutive patients undergoing noncardiac thoracic surgery. INTERVENTIONS: Focused TTE was performed during anesthetic induction after intubation for mechanical ventilation. Intraoperative focused TTE, after positioning and draping for surgery, was attempted again for all 105 patients. Changes in patient management due to the results of the TTE were documented and analyzed. MEASUREMENTS AND MAIN RESULTS: Presurgical TTE with mechanical ventilation was applied successfully in 98.1% of 105 patients. Intraoperative imaging was successful in 90 patients (85.7%). Results of intraoperative TTE led to the modification of perioperative management in 39 patients (37.1%), 20 (22.0%) of these during surgery. CONCLUSIONS: TTE in noncardiac thoracic surgery is feasible using a modified subcostal view and has an effect on hemodynamic management in a considerable number of patients.

Ultrasound-guided single injection versus continuous sciatic nerve blockade on pain management and mobilisation after total knee arthroplasty (CoSinUS trial): A randomised, triple-blinded controlled trial.

BACKGROUND: Combining continuous femoral nerve blockade with single injection sciatic nerve blockade is standard peripheral nerve block practice for total knee arthroplasty (TKA) during the first 24 postoperative hours. OBJECTIVES: To assess the analgesic benefits and mobilisation capability of continuous sciatic blockade in conjunction with continuous femoral nerve blockade for 72 h after arthroplasty. DESIGN: Randomised, triple-blinded controlled trial. SETTING: Single-Centre, German University Hospital. PATIENTS: In total, 50 patients receiving continuous femoral nerve blockade (5 ml h ropivacaine 0.2%) for TKA under general anaesthesia. INTERVENTIONS: Patients were randomised to receive a sciatic nerve catheter with an initial dose of 10 ml ropivacaine 0.2% followed by either continuous double-blinded application of 5 ml h ropivacaine 0.2% (CO) or 5 ml h saline infusion (SIN). MAIN OUTCOME: Measures primary endpoint: cumulative morphine consumption until 48 h postoperatively. Further endpoints included morphine consumption, pain scores, mobilisation, dynamometry until postoperative day 3. RESULTS: Median [25th to 75th percentiles] cumulative morphine consumption at postoperative day 2 differed significantly between groups (CO 15 mg [11 to 25] versus SIN, 43 mg [27 to 67.5, P < 0.0001) in the 48 patients in the final analysis. Overall pain scores were comparable at rest and during stress at each time point. However, significantly higher pain scores of the popliteal fossa were observed in the SIN group. Mobilisation was comparable between groups. CONCLUSION: This trial demonstrates the superior analgesic effects of continuous sciatic nerve block compared with a single injection in combination with continuous femoral blockade during the first 72 h after TKA. However, mobilisation capability was impaired in both groups. Improved pain control from two catheters needs to be balanced against the potential risks of impaired mobilisation and patient falls. TRIAL REGISTRATION: DRKS - German clinical trials register (no: DRKS00010152).

[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.

Suture or Stapling Are Superior in Comparison to Bipolar Sealing for Closing the Bronchi.

Background Every anatomical lung resection requires the airtight closure of at least one bronchus. In current clinical practice, these bronchi are sealed with sutures or staplers. This study investigated in an ex vivo pig model whether a new bipolar sealing device MARSEAL (KLS Martin, Tuttlingen, Germany) could be an alternative for this purpose. Methods Complete bronchial trees were prepared free from pig heart-lung blocks that were removed at a slaughterhouse. These preparations were taken to the laboratory, and main, lobar, and segmental bronchi were closed using sutures, staples, or bipolar sealing. Each trachea was then intubated and connected to a ventilating device. The initial airtight closure of the bronchus was first tested with lung-protective ventilation. After 15 minutes of ventilation, the inspiratory ventilation pressure was slowly increased and the burst pressure (in mbar) was recorded. Each group included 12 bronchus closures. Group mean burst pressures were compared using a nonparametric test (Mann-Whitney U test). The significance level was p < 0.05. Results The main bronchi closed both stapler magazines or sutures were all initially airtight during ventilation. The mean burst pressure was 60 ± 0 mbar for staplers and 57.92 ± 5.8 mbar for sutures. In contrast, 50% of main bronchi sealed with MARSEAL devices (5 or 10 mm) leaked air from the beginning. This was also noted in all lobar bronchi sealed with the MARSEAL 5-mm device and 80% of those sealed with the MARSEAL 10-mm device. The mean burst pressure of initially airtight lobar bronchi was 12.7 ± 7.25 mbar. In contrast, all segmental bronchi (mean width: 1.6 cm) were airtight when ventilated. Mean burst pressure was 14.64 ± 9.1 mbar with the MARSEAL 5-mm device and 29.64 ± 21.3 mbar with the MARSEAL 10-mm device. Histological investigation of the preparations (with hematoxylin and eosin staining) showed intact cartilaginous structures that were largely unaffected by bipolar coagulation. The airtight sealing of the segmental bronchi resulted from fusion of the peribronchial tissue and not the cartilage. Conclusion Bipolar sealing is an inappropriate tool for the closure of the bronchi in comparison to suture or stapling.

Impact of Focused Intraoperative Transthoracic Echocardiography by Anesthesiologists on Management in Hemodynamically Unstable High-Risk Noncardiac Surgery Patients.

OBJECTIVES: Focused transthoracic echocardiography (TTE) is used perioperatively for surgical patients. Intraoperative application of TTE is feasible, but its benefits remain unclear. The intention of this study was to investigate the effect of intraoperative TTE on the management of high-risk noncardiac surgery patients. DESIGN: A prospective interventional study. SETTING: Single-center university hospital. PARTICIPANTS: Fifty consecutive hemodynamically unstable high-risk patients anesthetized for noncardiac surgery. INTERVENTIONS: Focused TTE was performed on hemodynamically unstable anesthetized patients whenever circulatory instability (defined as hypotension or low cardiac output) occurred intraoperatively. A cardiac output monitoring system using pulse contour analysis was established before induction of anesthesia. The intended therapy for stabilizing the patient was documented; however, the management actually administered was guided by the results of the TTE. Differences between the 2 lines of management were documented and analyzed. MEASUREMENTS AND MAIN RESULTS: Intraoperative TTE was applied successfully in all 50 unstable patients. In 33 patients (66%, 95% confidence interval, 52.11-77.61) TTE led to a change of management. Altogether, 82 episodes of hemodynamic instability were recorded, including 38 episodes (46.34%, 95% confidence interval, 35.95-57.06) in which TTE led to a change of treatment. The most common pathologic finding was hypovolemia (66%); in contrast, in 22%, right-heart overload or right-heart failure (4%) was detected. CONCLUSIONS: Focused TTE by anesthesiologists can provide new information that may alter the hemodynamic management of unstable high-risk noncardiac surgery patients in the operating room.

Initial Resistance of Carina Anastomoses with Increasing Tensile Stress: An ex vivo Model Comparing Different Suture Techniques.

BACKGROUND: After resection of the carina with a length of more than 4 cm, anastomoses often need to be performed under tension despite maximum mobilization. If the patient cannot be extubated, the anastomosis remains under continued stress. Anastomoses of the carina can be constructed using various suture techniques, including single interrupted sutures, back wall running but front wall single interrupted sutures, and complete running suture. This experimental study was designed to determine the most tensile stress-resistant anastomotic suture technique. MATERIALS AND METHODS: Isolated preparations of tracheobronchial trees were recovered from freshly slaughtered pigs. Resection of the carina was carried out in preparation of the experiments. After blind randomization, anastomoses (n = 15 per group) between the distal trachea and the proximal left main bronchus were performed with PDS 4-0 employing three different suture techniques: (1) single interrupted sutures, (2) back wall running but front wall single interrupted sutures (= mixed technique), and (3) complete running suture. The anastomotic specimen was fixed onto a specially constructed device. The tracheal end was intubated with a tube (CH 8.0) and connected to a respirator. Different weights were attached to the distal end of the preparation via a clamp and guide rollers. Airtightness was investigated at the following tensile loads: 0, 500, 1,000 and 1,500 g. Intrabronchial pressure was increased in 5-mbar steps. In an underwater trial, we analyzed whether anastomoses were airtight at a maximum intrabronchial ventilation pressure of 70 mbar. RESULTS: At an intrabronchial pressure of 25 mbar without tensile stress, all anastomoses were initially airtight. In tensionless anastomoses at 70 mbar, 100% of single interrupted and continuous sutures were airtight, as compared to 80% of sutures in mixed technique. At 70 mbar and tensile loads of 1,500 g, 80% of single interrupted sutures, 60% of sutures in mixed technique and 53% of the running sutures remained competent. CONCLUSION: If tracheal anastomoses can be performed without tension, the suture technique is not important. With increased tension, anastomoses performed in single interrupted suture technique were clearly superior. Thus, in situations, where high tensile stress is to be expected, single interrupted sutures should be preferred.

Single-dose Antibiotic Prophylaxis in Regional Anesthesia: A Retrospective Registry Analysis.

BACKGROUND: Catheter-related infection is a serious complication of continuous regional anesthesia. The authors tested the hypothesis that single-dose antibiotic prophylaxis is associated with a lower incidence of catheter-related infections. METHODS: Our analysis was based on cases in the 25-center German Network for Regional Anesthesia database recorded between 2007 and 2014. Forty thousand three hundred sixty-two surgical patients who had continuous regional anesthesia were grouped into no antibiotic prophylaxis (n = 15,965) and single-dose antibiotic prophylaxis (n = 24,397). Catheter-related infections in each group were compared with chi-square test after 1:1 propensity-score matching. Odds ratios (ORs [95% CI]) were calculated with logistic regression and adjusted for imbalanced variables (standardized difference more than 0.1). RESULTS: Propensity matching successfully paired 11,307 patients with single-dose antibiotic prophylaxis (46% of 24,397 patients) and with 11,307 controls (71% of 15,965 patients). For peripheral catheters, the incidence without antibiotics (2.4%) was greater than with antibiotic prophylaxis (1.1%, P < 0.001; adjusted OR, 2.02; 95% CI, 1.49 to 2.75, P < 0.001). Infections of epidural catheters were also more common without antibiotics (5.2%) than with antibiotics (3.1%, P < 0.001; adjusted OR, 1.94; 95% CI, 1.55 to 2.43, P < 0.001). CONCLUSIONS: Single-dose antibiotic prophylaxis was associated with fewer peripheral and epidural catheter infections.

Awake, sedated or anaesthetised for regional anaesthesia block placements?: A retrospective registry analysis of acute complications and patient satisfaction in adults.

BACKGROUND: Whether adults should be awake, sedated or anaesthetised during establishment of regional anaesthesia is still debated and there is little information on the relative safety of each. In paediatric practice, there is often little choice but to use sedation or anaesthesia as otherwise the procedures would be too distressing and patient movement would be hazardous. OBJECTIVE(S): The objective of this study was to evaluate complications related to central and peripheral regional block and patient satisfaction in awake, sedated and anaesthetised adult patients. DESIGN: A retrospective registry analysis. SETTING: The German Network of Regional Anaesthesia database was analysed between 2007 and 2012. PATIENTS: We included data of 42 654 patients and defined three groups: group I awake (n = 25 004), group II sedated (n = 15 121) and group III anaesthetised (n = 2529) for block placement. MAIN OUTCOME MEASURES: Odds ratios [OR; 95% confidence interval (CI)] were calculated with logistic regression analysis and adjusted for relevant confounders to determine the risk of block-related complications in sedated or anaesthetised patients compared with awake patients. RESULTS: Rates of local anaesthetic systemic toxicity were comparable between the groups [awake 0.02% (95% CI: 0.002 to 0.0375), sedated 0.02% (0.003 to 0.042) and anaesthetised 0% (0 to 0.12%)], as were the rates of pneumothorax [awake 0.035% (0 to 0.074), sedated 0% (0 to 0.002) and anaesthetised 0.2% (0 to 0.56)]. Considering peripheral nerve blocks, sedated patients had a decreased risk for multiple skin puncture [adjusted OR: 0.78 (95% CI: 0.71 to 0.85), premature termination [0.45 (0.22 to 0.91)], primary failure [0.58 (0.40 to 0.83)] and postoperative paraesthesia [0.35 (0.28 to 0.45)], but an increased risk for a bloody tap [1.82 (1.50 to 2.21)]. General anaesthesia increased the risk of a bloody tap [adjusted OR: 1.33 (95% CI: 1.01 to 1.78)] and multiple skin puncture [1.28 (1.12 to 1.46)], but decreased the risk for postoperative paraesthesia [0.16 (0.06 to 0.38)]. In neuraxial sites, sedation increased the risk for multiple skin puncture [adjusted OR: 1.18 (95% CI: 1.09 to 1.29)], whereas block placement under general anaesthesia decreased the risk for multiple skin puncture [0.53 (0.39 to 0.72)] and bloody tap but significantly increased the risk for postoperative paraesthesia related to a catheter [2.45 (1.19 to 5.02)]. Sedation was associated with a significant improvement in patient satisfaction. CONCLUSION: Sedation may improve safety and success of peripheral nerve block placement. Block placement under general anaesthesia in adults should be reserved for experienced anaesthesiologists and special situations.

Continuous adductor canal block versus continuous femoral nerve block after total knee arthroplasty for mobilisation capability and pain treatment: a randomised and blinded clinical trial.

INTRODUCTION: Continuous femoral nerve blocks for total knee arthroplasty can cause motor weakness of the quadriceps muscle and thus prevent early mobilisation. Perioperative falls may result as an iatrogenic complication. In this randomised and blinded trial, we tested the hypothesis that a continuous adductor canal block is superior to continuous femoral nerve block regarding mobilisation ('timed up-and-go' test and other tests) after total knee arthroplasty under general anaesthesia. METHODS: In our study, we included patients scheduled for unilateral knee arthroplasty under general anaesthesia into a blinded and randomised trial. Patients were allocated to a continuous adductor canal block (CACB) or a continuous femoral nerve block (CFNB) for three postoperative days (POD 1-3); with a bolus of 15 ml ropivacaine 0.375%, followed by continuous infusion of ropivacaine 0.2% and patient-controlled bolus administration. Both groups received an additional continuous sciatic nerve block as well as a multimodal systemic analgesic treatment. The primary outcome parameter was mobilisation capability, assessed by 'timed up-and-go' (TUG) test. Analgesic quality, need for opioid rescue and local anaesthetic consumption were also assessed. RESULTS: Forty-two patients were included and analysed (21 patients per group). No significant difference was noted in respect to mobilisation at POD 3 (TUG [s]: CACB 45, CFNB 51). It is worth saying that pain scores (numeric rating scale, NRS) were similar in both groups at POD 3 {rest [median (interquartile range)]: CACB 0 (0-3), CFNB 1 (0-3); stress: CACB 4 (2-5), CFNB 3 (2-4)}. CONCLUSIONS: Concerning the mobilisation capability, we did not actually observe a superior effect of CACB compared with CFNB technique in our patients following total knee arthroplasty. Moreover, no difference was observed concerning analgesia quality.

[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.

[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.

Mechanical ventilation during cardiopulmonary resuscitation with intermittent positive-pressure ventilation, bilevel ventilation, or chest compression synchronized ventilation in a pig model.

OBJECTIVE: Mechanical ventilation with an automated ventilator is recommended during cardiopulmonary resuscitation with a secured airway. We investigated the influence of intermittent positive-pressure ventilation, bilevel ventilation, and the novel ventilator mode chest compression synchronized ventilation, a pressure-controlled ventilation triggered by each chest compression, on gas exchange, hemodynamics, and return of spontaneous circulation in a pig model. DESIGN: Animal study. SETTING: University laboratory. SUBJECTS: Twenty-four three-month-old female domestic pigs. INTERVENTIONS: The study was performed on pigs under general anesthesia with endotracheal intubation. Arterial and central venous catheters were inserted and IV rocuronium (1 mg/kg) was injected. After 3 minutes of cardiac arrest (ventricular fibrillation at t = 0 min), animals were randomized into intermittent positive-pressure ventilation (control group), bilevel, or chest compression synchronized ventilation group. Following 10 minute uninterrupted chest compressions and mechanical ventilation, advanced life support was performed (100% O2, up to six defibrillations, vasopressors). MEASUREMENTS AND MAIN RESULTS: Blood gas samples were drawn at 0, 4 and 13 minutes. At 13 minutes, hemodynamics was analyzed beat-to-beat in the end-inspiratory and end-expiratory cycle comparing the IPPV with the bilevel group and the CCSV group. Data were analyzed with the Mann-Whitney U test. Return of spontaneous circulation was achieved in five of eight (intermittent positive-pressure ventilation), six of eight (bilevel), and four of seven (chest compression synchronized ventilation) pigs. The results of arterial blood gas analyses at t = 4 minutes and t = 13 minutes (torr) were as follows: PaO2 intermittent positive-pressure ventilation, 143 (76/256) and 262 (81/340); bilevel, 261 (109/386) (p = 0.195 vs intermittent positive-pressure ventilation) and 236 (86/364) (p = 0.878 vs intermittent positive-pressure ventilation); and chest compression synchronized ventilation, 598 (471/650) (p < 0.001 vs intermittent positive-pressure ventilation) and 634 (115/693) (p = 0.054 vs intermittent positive-pressure ventilation); PaCO2 intermittent positive-pressure ventilation, 40 (38/43) and 45 (36/52); bilevel, 39 (35/41) (p = 0.574 vs intermittent positive-pressure ventilation) and 46 (42/49) (p = 0.798); and chest compression synchronized ventilation, 28 (27/32) (p = 0.001 vs intermittent positive-pressure ventilation) and 26 (18/29) (p = 0.004); mixed venous pH intermittent positive-pressure ventilation, 7.34 (7.31/7.35) and 7.26 (7.25/7.31); bilevel, 7.35 (7.29/7.37) (p = 0.645 vs intermittent positive-pressure ventilation) and 7.27 (7.17/7.31) (p = 0.645 vs intermittent positive-pressure ventilation); and chest compression synchronized ventilation, 7.34 (7.33/7.39) (p = 0.189 vs intermittent positive-pressure ventilation) and 7.35 (7.34/7.36) (p = 0.006 vs intermittent positive-pressure ventilation). Mean end-inspiratory and end-expiratory arterial pressures at t = 13 minutes (mm Hg) were as follows: intermittent positive-pressure ventilation, 28.0 (25.0/29.6) and 27.9 (24.4/30.0); bilevel, 29.1 (25.6/37.1) (p = 0.574 vs intermittent positive-pressure ventilation) and 28.7 (24.2/36.5) (p = 0.721 vs intermittent positive-pressure ventilation); and chest compression synchronized ventilation, 32.7 (30.4/33.4) (p = 0.021 vs intermittent positive-pressure ventilation) and 27.0 (24.5/27.7) (p = 0.779 vs intermittent positive-pressure ventilation). CONCLUSIONS: Both intermittent positive-pressure ventilation and bilevel provided similar oxygenation and ventilation during cardiopulmonary resuscitation. Chest compression synchronized ventilation elicited the highest mean arterial pressure, best oxygenation, and a normal mixed venous pH during cardiopulmonary resuscitation.

Bipolar impedance-controlled sealing of the pulmonary artery with SealSafe G3 electric current: determination of bursting pressures in an ex vivo model.

BACKGROUND: In every anatomic lung resection operation, the pulmonary artery itself or its branches must be sealed. This involves either stapling or ligating the vessels. Based on the positive results with the bipolar vessel sealing ≤7 mm in abdominal surgery the present study aimed to evaluate burst pressures of the pulmonary artery after sealing with the sealing instrument SealSafe G3 (Gebrüder Martin & CoKG, Tuttlingen, Germany). MATERIAL AND METHODS: The whole pulmonary artery above the pulmonary valve was exposed up to the periphery of the left lung in freshly removed pig heart-lung blocks. A pressure-measuring cylinder was then implanted in the prepared vessel on the side at the main trunk of the pulmonary artery to determine the pressure in the vessel. After either ligation or bipolar sealing of the pulmonary artery, the pneumatic burst pressure (millimeters of mercury) was determined in a water bath. Three groups (n = 12 for each seal type) with different vessel diameters were examined: group 1: 0-6 mm, group 2: 7-12 mm, and group 3: >12 mm. In all cases, vessel sealing was performed with a MARSEAL 5 instrument (Gebrüder Martin & Co KG, Tuttlingen, Germany) and the SealSafe G3 current. The mean burst pressures of the individual groups (ligature and bipolar sealing) were compared using two-tailed, nonparametric Mann-Whitney U test. Significance was defined as P < 0.05. RESULTS: The mean burst pressures in group 1 were measured by 340 ± 13.4 mm Hg with ligature and 205 ± 44.4 mm Hg with bipolar sealing (P < 0.001). In group 2, the mean values obtained were 270 ± 28.2 mm Hg for ligature and 162 ± 36.0 mm Hg for bipolar sealing (P < 0.001). In group 3, the mean burst pressures for bipolar sealing were only 52.1 ± 15.1 mm Hg, whereas those for ligated vessels were 253 ± 46.9 mm Hg (P < 0.001). For this size of vessel the burst pressure was also determined after stapling. The mean value in this case was 230 ± 21.8 mm Hg. CONCLUSIONS: In all groups, the mean burst pressures after bipolar sealing were significantly lower than those achieved with ligation, but they were sufficient for a save closure of the pulmonary artery with diameters up to 12 mm.