Nervus Femoralis-Katheter in der postoperativen Analgesie nach komplexen Knieoperationen: Stimulationskatheter oder konventionell gelegter Katheter- was ist sinnvoller?

Die kontinuierliche Nervus femoralis-Blockade gewährleistet in der postoperativen Behandlung nach komplexen Knieeingriffen eine effektive Schmerztherapie und wird daher gern und häufig angewendet. Jedoch ist die Rate an Therapieversagern mit 10-40% relativ hoch. Eine mögliche ursächliche Erklärung für diese Fälle mit unbefriedigender Analgesie ist die Gegebenheit, dass die exakte Positionierung des Katheters in unmittelbarer Nervennähe während der Anlage nicht kontrolliert werden kann. Daher stellt die Entwicklung eines elektrisch stimulierbaren Katheters mit der Möglichkeit zur genauen Lokalisation in unmittelbarer Nähe zum Nerv während der Anlage eine viel versprechende Neuerung dar. Allerdings ist bisher kein Nachweis dafür erbracht worden, dass eine exaktere Katheterplatzierung mittels Stimulation durch eine verbesserte Nervenblocke zu einem verbesserten klinischen Ergebnis im Vergleich zur konventionellen Methode führt. In der vorliegenden Studie wird der Frage nachgegangen, ob durch Stimulationskatheter eine effizientere postoperative Analgesie sowie eine verbesserte funktionelle Rehabilitation als durch konventionelle Katheter erreicht werden kann.In der vorliegenden prospektiven, randomisierten und untersucherblinden Studie wurde nach Genehmigung durch die Ethikkommission und Patienteneinverständnis die konventionelle Technik der Katheterplatzierung mit der neuen Stimulationskathetertechnik verglichen. 81 Patienten erhielten für komplexe Knieeingriffe eine kontinuierliche Nervus femoralis-Blockade, 38 Patienten mittels Stimulationskatheter und 43 Patienten anhand eines konventionellen Katheters. Die Daten der postoperativen Schmerzbehandlung (Piritramidverbrauch) wurden über einen Zeitraum von 48 Stunden erhoben, in der Rehabilitation wurden die Patienten über 5 Tage untersucht (Kniebeweglichkeit sowie Schmerzintensität). Die zusätzlich zur Regionalanästhesie benötigten systemischen Analgetikamengen unterschieden sich weder in der unmittelbar postoperativen Phase, noch bei der längerfristigen Beobachtung über 48 Stunden zwischen der Stimulationskatheter- und der konventionellen Kathetergruppe signifikant (p = 0,110). Die folgenden Angaben beziehen sich auf den Median, in Klammern die Interquartilsabstände. Der Gesamt-Piritramidverbrauch nach 48 Stunden betrug in der Studiengruppe 49 (17 / 69) mg und in der Kontrollgruppe 56 (34 / 73) mg (p = 0,290). Auch in der von den Patienten empfundenen Schmerzintensität stellte sich an Tag 2 kein Unterschied (p = 0,152) zwischen den Stimulationskathetern (VAS 4 (4 / 5) bei Bewegung und VAS 2,5 (1 / 4) in Ruhe) und den konventionellen Kathetern (VAS 5 (3 / 7) bei Bewegung und VAS 1 (0 / 3) in Ruhe) heraus. In den funktionellen Rehabilitationsergebnissen waren beide Kathetertypen vergleichbar (p = 0,226). Die Beugefähigkeit im Kniegelenk nahm in der Studiengruppe von 40° (35° / 48,8°) am ersten postoperativen Tag auf 90° (85° / 90°) am fünften Tag zu und in der Kontrollgruppe von 40° (30° / 47,5°) auf 80° (70° / 90°). Auch die Streckfähigkeit verbesserte sich in beiden Gruppen (von 10° (5° / 10°) auf 0° (0° / 5°) in der Studiengruppe und von 10° (10° / 15°) auf 5° (0° / 5°) in der Kontrollgruppe).Es zeigte sich, dass bei oben genannter Indikation keine Verbesserung der postoperativen Schmerztherapie durch die neuen Stimulationskatheter erreicht werden konnte. Auch eine verbesserte funktionelle Rehabilitation oder höherer Patientenkomfort konnte nicht nachgewiesen werden. Es lassen sich mit dem heutigen Wissensstand keine eindeutigen Vorteile in der Effektivität der Stimulationskatheter bei der untersuchten Indikation nachweisen, so dass sich die höheren Kosten dieser Katheter nicht rentieren. Die Verwendung der Stimulationskatheter in der Routine kann derzeit nicht empfohlen werden. Da die stimulierbaren Katheter aber eine exaktere Platzierung in Nervennähe gewährleisten, sind weitere Untersuchungen notwendig, um eine objektive Aussage über den Nutzen der Stimulationskatheter für weitere Indikationen zu treffen

Verkürzung der Zeitintervalle bis zur Erstdefibrillation und Intubation bei der kardiopulmonalen Reanimation durch ein Ventilations- Kompressionsverhältnis von 5:50 statt 2:15 - eine kontrollierte Studie der Arbeitsabläufe unter BLS am Modell

In der ersten Phase einer kardiopulmonalen Reanimation durch zwei professionelle Helfer müssen Advanced-Cardiac-Life-Support (ACLS) -Maßnahmen (Frühdefibrillation, Intubation und die Medikamentenapplikation) möglichst ohne Unterbrechung der Basic-Life-Support (BLS) -Maßnahmen (Beatmung und die externe Herzdruckmassage) durchgeführt werden. Das Ziel dieser Studie war es, den Unterschied zwischen den Zeitintervallen vom Beginn der BLS-Maßnahmen bis zur 1. Defibrillation und vom Beginn der BLS -Maßnahmen bis zur Intubation bei zwei unterschiedlichen Ventilations-Kompressionsverhältnisse zu untersuchen. Es wurden die Ventilations-Kompressionsverhältnisse 2:15 (Methode A: heutiger Standard) und 5:50 (Methode B: alternatives Verfahren) ausgewählt. In einer randomisierten Studie führten 40 in kardiopulmonaler Reanimation trainierte Helfer (Rettungsassistenten/-sanitäter) wechselweise eine standardisierte Reanimation mit BLS- und ACLS-Maßnahmen mit einem Ventilations-Kompressionsverhältnisses von 2:15 und 5:50 gemäß den heute gültigen Richtlinien von der ILCOR (International Liaison Committee of Resuscitation) an einem Reanimationsmodell (Resusci Skillreporter Anne, Laerdal, Norwegen) durch. Die BLS-Maßnahmen wurden mit der Ventilation mittels Beatmungsbeutel und -maske begonnen, ein halbautomatischer Defibrillator (Corpuls 08/16S biphasic) wurde konnektiert, die EKG Analyse (Kammerflimmern) durchgeführt, 3 Schocks ausgelöst und die endotracheale Intubation vorbereitet. Ventilation und kardiale Kompressionen wurden nur für die EKG Analyse und die Defibrillation unterbrochen. Das Atemminutenvolumen (AMV) und die Anzahl der Kompressionen wurden erhoben und die Zeit der obengenannten Zeitintervallen mittels eines gepaarten t-Test verglichen. Zusätzlich wurde das Rettungsdienstpersonal über den Arbeitsablauf und den emotionalen Stress während des Tests vergleichend befragt. Die Zeitintervalle vom Start der BLS-Maßnahmen bis zum 1. Schock waren 78s (2:15) gegenüber 63s (5:50), p0,1 und die durchschnittliche Anzahl der Kompressionen 65/min (2:15) bzw 68/min (5:50), p>0,1. Der Arbeitsablauf verlief bei 5:50 subjektiv ruhiger und der emotionale Stress während der Versuche wurde von dem Rettungsdienstpersonal als signifikant geringer bei 5:50, p<0,0001 eingestuft. Zusammenfassend kann man sagen, dass die Frühdefibrillation und die Intubation bei der alternativen Methode B (5:50) signifikant eher erfolgte bei gleichbleibendem AMV und durchschnittlichen Anzahl der Kompressionen. Weiterhin wurde der Arbeitsablauf während der ersten Phase der Reanimation bei der Methode B verbessert und der Stress der Helfer verringert

Recommendations for anesthesia and perioperative management in patients with Ehlers-Danlos syndrome(s)

Ehlers-Danlos syndrome (EDS, ORPHA98249) comprises a group of clinically and genetically heterogeneous heritable connective tissue disorders, chiefly characterized by joint hypermobility and instability, skin texture anomalies, and vascular and soft tissue fragility. As many tissues can be involved, the underlying molecular defect can manifest itself in many organs and with varying degrees of severity, with widespread implications for anesthesia and perioperative management. This review focuses on issues relevant for anesthesia for elective and emergency surgery in EDS. We searched the literature for papers related to all EDS variants; at the moment most of the published data deals with the vascular subtype and, to a lesser extent, classic and hypermobility EDS. Knowledge is fragmented and consists mostly of case reports, small case series and expert opinion. Because EDS patients commonly require surgery, we have summarized some recommendations for general, obstetrical and regional anesthesia, as well as for hemostatic therapy

Quantification of exhaled propofol is not feasible during single-lung ventilation using double-lumen tubes : A multicenter prospective observational trial

Background: Volatile propofol can be measured in exhaled air and correlates to plasma concentrations with a time delay. However, the effect of single-lung ventilation on exhaled propofol is unclear. Therefore, our goal was to evaluate exhaled propofol concentrations during single-lung compared to double-lung ventilation using double-lumen tubes. Methods: In a first step, we quantified adhesion of volatile propofol to the inner surface of double-lumen tubes during double- and single-lumen ventilation in vitro. In a second step, we enrolled 30 patients scheduled for lung surgery in two study centers. Anesthesia was provided with propofol and remifentanil. We utilized left-sided double-lumen tubes to separately ventilate each lung. Exhaled propofol concentrations were measured at 1-min intervals and plasma for propofol analyses was sampled every 20 min. To eliminate the influence of dosing on volatile propofol concentration, exhalation rate was normalized to plasma concentration. Results: In-vitro ventilation of double-lumen tubes resulted in increasing propofol concentrations at the distal end of the tube over time. In vitro clamping the bronchial lumen led to an even more pronounced increase (Δ AUC +62%) in propofol gas concentration over time. Normalized propofol exhalation during lung surgery was 31% higher during single-lung compared to double-lung ventilation. Conclusion: During single-lung ventilation, propofol concentration in exhaled air, in contrast to our expectations, increased by approximately one third. However, this observation might not be affected by change in perfusion-ventilation during singlelung ventilation but rather arises from reduced propofol absorption on the inner surface area of the double-lumen tube. Thus, it is only possible to utilize exhaled propofol concentration to a limited extent during single-lung ventilation. Registration of Clinical Trial: DRKS-ID DRKS00014788 (www.drks.de)

Hypotension Prediction Index Software to Prevent Intraoperative Hypotension during Major Non-Cardiac Surgery: Protocol for a European Multicenter Prospective Observational Registry (EU-HYPROTECT)

Intraoperative hypotension is common in patients having non-cardiac surgery and associated with postoperative acute myocardial injury, acute kidney injury, and mortality. Avoiding intraoperative hypotension is a complex task for anesthesiologists. Using artificial intelligence to predict hypotension from clinical and hemodynamic data is an innovative and intriguing approach. The AcumenTM Hypotension Prediction Index (HPI) software (Edwards Lifesciences; Irvine, CA, USA) was developed using artificial intelligence-specifically machine learning-and predicts hypotension from blood pressure waveform features. We aimed to describe the incidence, duration, severity, and causes of intraoperative hypotension when using HPI monitoring in patients having elective major non-cardiac surgery

Hypotension prediction index software to prevent intraoperative hypotension during major non-cardiac surgery: protocol for a european multicenter prospective observational registry (EU-HYPROTECT)

Background: Intraoperative hypotension is common in patients having non-cardiac surgery and associated with postoperative acute myocardial injury, acute kidney injury, and mortality. Avoiding intraoperative hypotension is a complex task for anesthesiologists. Using artificial intelligence to predict hypotension from clinical and hemodynamic data is an innovative and intriguing approach. The AcumenTM Hypotension Prediction Index (HPI) software (Edwards Lifesciences; Irvine, CA, USA) was developed using artificial intelligence-specifically machine learning-and predicts hypotension from blood pressure waveform features. We aimed to describe the incidence, duration, severity, and causes of intraoperative hypotension when using HPI monitoring in patients having elective major non-cardiac surgery. Methods: We built up a European, multicenter, prospective, observational registry including at least 700 evaluable patients from five European countries. The registry includes consenting adults (?18 years) who were scheduled for elective major non-cardiac surgery under general anesthesia that was expected to last at least 120 min and in whom arterial catheter placement and HPI monitoring was planned. The major objectives are to quantify and characterize intraoperative hypotension (defined as a mean arterial pressure [MAP] &lt; 65 mmHg) when using HPI monitoring. This includes the time-weighted average (TWA) MAP &lt; 65 mmHg, area under a MAP of 65 mmHg, the number of episodes of a MAP &lt; 65 mmHg, the proportion of patients with at least one episode (1 min or more) of a MAP &lt; 65 mmHg, and the absolute maximum decrease below a MAP of 65 mmHg. In addition, we will assess causes of intraoperative hypotension and investigate associations between intraoperative hypotension and postoperative outcomes. Discussion: There are only sparse data on the effect of using HPI monitoring on intraoperative hypotension in patients having elective major non-cardiac surgery. Therefore, we built up a European, multicenter, prospective, observational registry to describe the incidence, duration, severity, and causes of intraoperative hypotension when using HPI monitoring in patients having elective major non-cardiac surgery.Funding: Edwards Lifesciences SA, Department of Critical Care, Route de l’Etraz 70, 1260 Nyon, Switzerland funded the study and acts as the legal sponsor. The sponsor/funder had an active role in the design of the study. The collection, analysis, and interpretation of the data will be a collaborative effort of all investigators, who will also write the manuscript. Acknowledgments: We acknowledge the support of all participating patients and their physicians. We also acknowledge the tremendous contribution of the staff at Edwards Lifesciences, especially Edward Hembrow, Tim van den Boom, Anne Halfmann, Pierre Sibileau, Barbara Plasschaert, Volker Haag, Giulia Torricella and Alessia Longo. We further appreciate the excellent project management secured by Daniel Greinert, Marie Zielinksi and Claudia Lüske at the Institute for Pharmacology and Preventive Medicine (Cloppenburg, Germany). Data are captured using the s4trials software provided by Software for Trials Europe GmbH (Berlin, Germany)

Factors influencing preoperative stress response in coronary artery bypass graft patients

BACKGROUND: In many studies investigating measures to attenuate the hemodynamic and humoral stress response during induction of anaesthesia, primary attention was paid to the period of endotracheal intubation since it has been shown that even short-lasting sympathetic cardiovascular stimulation may have detrimental effects on patients with coronary artery disease. The aim of this analysis was, however, to identify the influencing factors on high catecholamine levels before induction of anaesthesia. METHODS: Various potential risk factors that could impact the humoral stress response before induction of anaesthesia were recorded in 84 males undergoing coronary aortic bypass surgery, and were entered into a stepwise linear regression analysis. The plasma level of norepinephrine measured immediately after radial artery canulation was chosen as a surrogate marker for the humoral stress response, and it was used as the dependent variable in the regression model. Accordingly, the mean arterial blood pressure, heart rate and the calculated pressure-rate product were taken as parameters of the hemodynamic situation. RESULTS: Stepwise regression analysis revealed that the oral administration of low-dose clonidine (mean dose 1.75 μg·kg(-1)) on the morning of surgery was the only significant predictor (p = 0.004) of the high variation in preoperative norepinephrine plasma levels. This intervention decreased norepinephrine levels by more than 40% compared to no clonidine administration, from 1.26 to 0.75 nmol·l(-1). There was no evidence for dose-responsiveness of clonidine. All other potential predictors were removed from the model as insignificant (p > 0.05). The use of beta-blocker, ace-inhibitors, ejection fraction, and body mass index were significant determinants for the hemodynamic situation (heart rate, mean arterial pressure, pressure rate product) of the patient during the pre-induction period. CONCLUSION: The oral administration of clonidine is the only significant predictor for the observed variation of norepinephrine levels during the preoperative period. Lack of significant dose responsiveness suggests that even a low dose of the drug can attenuate the preoperative stress response and thus is recommended in cardiovascular high risk patients

Risk factors for bacterial catheter colonization in regional anaesthesia

BACKGROUND: Although several potential risk factors have been discussed, risk factors associated with bacterial colonization or even infection of catheters used for regional anaesthesia are not very well investigated. METHODS: In this prospective observational trial, 198 catheters at several anatomical sites where placed using a standardized technique. The site of insertion was then monitored daily for signs of infection (secretion at the insertion site, redness, swelling, or local pain). The catheters were removed when clinically indicated (no or moderate postoperative pain) or when signs of potential infection occurred. After sterile removal they were prospectively analyzed for colonization, defined as > 15 colony forming units. RESULTS: 33 (16.7%) of all catheters were colonized, and 18 (9.1%) of these with additional signs of local inflammation. Two of these patients required antibiotic treatment due to superficial infections. Stepwise logistic regression analysis was used to identify factors associated with catheter colonization. Out of 26 potential factors, three came out as statistically significant. Catheter placement in the groin (odds-ratio and 95%-confidence interval: 3.4; 1.5–7.8), and repeated changing of the catheter dressing (odds-ratio: 2.1; 1.4–3.3 per removal) increased the risk for colonization, whereas systemic antibiotics administered postoperatively decreased it (odds ratio: 0.41; 0.12–1.0). CONCLUSION: Colonization of peripheral and epidural nerve catheter can only in part be predicted at the time of catheter insertion since two out of three relevant variables that significantly influence the risk can only be recorded postoperatively. Catheter localisation in the groin, removal of the dressing and omission of postoperative antibiotics were associated with, but were not necessarily causal for bacterial colonization. These factors might help to identify patients who are at increased risk for catheter colonization

Biomarker-guided intervention to prevent acute kidney injury after major surgery (BigpAK-2 trial): study protocol for an international, prospective, randomised controlled multicentre trial

IntroductionPrevious studies demonstrated that the implementation of the Kidney Disease Improving Global Outcomes (KDIGO) guideline-based bundle, consisting of different supportive measures in patients at high risk for acute kidney injury (AKI), might reduce rate and severity of AKI after surgery. However, the effects of the care bundle in broader population of patients undergoing surgery require confirmation.Methods and analysisThe BigpAK-2 trial is an international, randomised, controlled, multicentre trial. The trial aims to enrol 1302 patients undergoing major surgery who are subsequently admitted to the intensive care or high dependency unit and are at high-risk for postoperative AKI as identified by urinary biomarkers (tissue inhibitor of metalloproteinases 2*insulin like growth factor binding protein 7 (TIMP-2)*IGFBP7)). Eligible patients will be randomised to receive either standard of care (control) or a KDIGO-based AKI care bundle (intervention). The primary endpoint is the incidence of moderate or severe AKI (stage 2 or 3) within 72 hours after surgery, according to the KDIGO 2012 criteria. Secondary endpoints include adherence to the KDIGO care bundle, occurrence and severity of any stage of AKI, change in biomarker values during 12 hours after initial measurement of (TIMP-2)*(IGFBP7), number of free days of mechanical ventilation and vasopressors, need for renal replacement therapy (RRT), duration of RRT, renal recovery, 30-day and 60-day mortality, intensive care unit length-of-stay and hospital length-of-stay and major adverse kidney events. An add-on study will investigate blood and urine samples from recruited patients for immunological functions and kidney damage.Ethics and disseminationThe BigpAK-2 trial was approved by the Ethics Committee of the Medical Faculty of the University of Münster and subsequently by the corresponding Ethics Committee of the participating sites. A study amendment was approved subsequently. In the UK, the trial was adopted as an NIHR portfolio study. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and will guide patient care and further research.Trial registration numberNCT04647396

Short term non-invasive ventilation post-surgery improves arterial blood-gases in obese subjects compared to supplemental oxygen delivery - a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>In the immediate postoperative period, obese patients are more likely to exhibit hypoxaemia due to atelectasis and impaired respiratory mechanics, changes which can be attenuated by non-invasive ventilation (NIV). The aim of the study was to evaluate the duration of any effects of early initiation of short term pressure support NIV vs. traditional oxygen delivery via venturi mask in obese patients during their stay in the PACU.</p> <p>Methods</p> <p>After ethics committee approval and informed consent, we prospectively studied 60 obese patients (BMI 30-45) undergoing minor peripheral surgery. Half were randomly assigned to receive short term NIV during their PACU stay, while the others received routine treatment (supplemental oxygen via venturi mask). Premedication, general anaesthesia and respiratory settings were standardized. We measured arterial oxygen saturation by pulse oximetry and blood gas analysis on air breathing. Inspiratory and expiratory lung function was measured preoperatively (baseline) and at 10 min, 1 h, 2 h, 6 h and 24 h after extubation, with the patient supine, in a 30 degrees head-up position. The two groups were compared using repeated-measure analysis of variance (ANOVA) and t-test analysis. Statistical significance was considered to be P < 0.05.</p> <p>Results</p> <p>There were no differences at the first assessment. During the PACU stay, pulmonary function in the NIV group was significantly better than in the controls (p < 0.0001). Blood gases and the alveolar to arterial oxygen partial pressure difference were also better (p < 0.03), but with the addition that overall improvements are of questionable clinical relevance. These effects persisted for at least 24 hours after surgery (p < 0.05).</p> <p>Conclusion</p> <p>Early initiation of short term NIV during in the PACU promotes more rapid recovery of postoperative lung function and oxygenation in the obese. The effect lasted 24 hours after discontinuation of NIV. Patient selection is necessary in order to establish clinically relevant improvements.</p> <p>Trial Registration#</p> <p>DRKS00000751; <url>http://www.germanctr.de</url></p