Prämedikationsqualität und Patientenzufriedenheit nach Prämedikation mit Midazolam, Clonidin oder Placebo: Randomisierte Doppelblindstudie mit altersangepasster Dosierung

Zusammenfassung: Hintergrund: Die Prämedikation hat u.a. zum Ziel, Angstgefühle und innere Unruhe vor einem chirurgischen Eingriff zu lindern und gleichzeitig möglichst wenig unerwünschte Wirkungen zu verursachen. Es gibt bisher keine Untersuchungen, die die Wirkungen und Nebenwirkungen von Clonidin (Catapresan®), Midazolam (Dormicum®) und Placebo in altersabhängig unterschiedlicher Dosierung verglichen und deren Akzeptanz beim Patienten untersucht haben. Patienten und Methoden: In dieser randomisierten, placebokontrollierten Studie wurden 139 erwachsene Patienten untersucht und 60min vor der Narkoseeinleitung mit Clonidin, Midazolam oder Placebo prämediziert. Angst, Sedierungstiefe und Nebenwirkungen wurden an 6 aufeinanderfolgenden Zeitpunkten erfasst. Ergebnisse: Midazolam zeigte eine stärkere anxiolytische und sedative Wirkung als Clonidin. Die Prämedikation mit Midazolam verminderte die Sauerstoffsättigung. Es gab keine klinisch relevanten Veränderungen in der Hämodynamik in allen Gruppen. Midazolam und Clonidin verminderten das Risiko für "postoperative nausea and vomiting" (PONV). Midazolam zeigte die geringsten Nebenwirkungen. Placebo wurde von den Patienten weitaus am schlechtesten beurteilt, im Gegensatz zu Clonidin und Midazolam, das am besten beurteilt wurde. Schlussfolgerung: Die sedierende und anxiolytische Wirkung von Midazolam ist stärker als diejenige von Clonidin. Midazolam wurde von den Patienten besser angenommen als Clonidin, Clonidin siginfikant besser als Placebo. Die meisten Patienten würden Midazolam wieder wähle

Updates in perioperative coagulation: physiology and management of thromboembolism and haemorrhage

Understanding of blood coagulation has evolved significantly in recent years. Both new coagulation proteins and inhibitors have been found and new interactions among previously known components of the coagulation system have been discovered. This increased knowledge has led to the development of various new diagnostic coagulation tests and promising antithrombotic and haemostatic drugs. Several such agents are currently being introduced into clinical medicine for both the treatment or prophylaxis of thromboembolic disease and for the treatment of bleeding. This review aims to elucidate these new concepts and to outline some consequences for clinical anaesthesia and perioperative medicine

Allogeneic red blood cell transfusions: efficacy, risks, alternatives and indications

Careful assessment of risks and benefits has to precede each decision on allogeneic red blood cell (RBC) transfusion. Currently, a number of key issues in transfusion medicine are highly controversial, most importantly the influence of different transfusion thresholds on clinical outcome. The aim of this article is to review current evidence on blood transfusions, to highlight 'hot topics' with respect to efficacy, outcome and risks, and to provide the reader with transfusion guidelines. In addition, a brief synopsis of transfusion alternatives will be given. Based on up-to-date information of current evidence, together with clinical knowledge and experience, the physician will be able to make transfusion decisions that bear the lowest risk for the patient

Coagulopathy and blood component transfusion in trauma

Trauma is a serious global health problem, accounting for approximately one in 10 deaths worldwide. Uncontrollable bleeding accounts for 39% of trauma-related deaths and is the leading cause of potentially preventable death in patients with major trauma. While bleeding from vascular injury can usually be repaired surgically, coagulopathy-related bleeding is often more difficult to manage and may also mask the site of vascular injury. The causes of coagulopathy in patients with severe trauma are multifactorial, including consumption and dilution of platelets and coagulation factors, as well as dysfunction of platelets and the coagulation system. The interplay between hypothermia, acidosis and progressive coagulopathy, referred to as the 'lethal triad', often results in exsanguination. Current management of coagulopathy-related bleeding is based on blood component replacement therapy. However, there is a limit on the level of haemostasis that can be restored by replacement therapy. In addition, there is evidence that transfusion of red blood cells immediately after injury increases the incidence of post-injury infection and multiple organ failure. Strategies to prevent significant coagulopathy and to control critical bleeding effectively in the presence of coagulopathy may decrease the requirement for blood transfusion, thereby improving clinical outcome of patients with major trauma

Allogeneic blood transfusions: benefit, risks and clinical indications in countries with a low or high human development index.

The risks associated with allogeneic red blood cell (RBC) transfusions differ significantly between countries with low and high human development indexes (HDIs). In countries with a low HDI, the risk of infection (HIV, HBV, HCV and malaria) is elevated. In contrast, in countries with a high HDI, immunological reactions (haemolytic transfusion reactions, alloimmunization and immunosuppression) are predominant. Therefore the overall risk associated with RBC transfusions in low HDI countries is much more significant than that in high HDI countries. In view of these risks, the limited efficacy of RBC transfusion and its high costs, this procedure should be used sparingly and rationally. Therefore RBC transfusion protocols adapted to the local situation are essential. Such protocols should distinguish between physiological and haemoglobin-based transfusion triggers. In countries with a high HDI, relative tachycardia and hypotension, despite normovolaemia, ST-segment changes suggestive of myocardial ischaemia and an Hb level <6 g/dl can serve as general guidelines for transfusion. Higher haemoglobin transfusion triggers should be used for patients aged >80 years and those with coronary artery or cerebrovascular disease. In countries with a low HDI, clinical signs of circulatory failure or myocardial ischaemia and an Hb level <5 g/dl can serve as transfusion guidelines

Effect of a factor-based coagulation management on blood product use after major burn injury: A retrospective cohort study.

Transfusion of allogenic blood products was shown to be associated with more adverse events and a higher mortality in severely burned patients. This study investigated the impact of a goal-directed and factor-based coagulation algorithm on blood product use and clinical outcomes in severely burned patients. This retrospective cohort study included adult patients admitted to the burn center of the University Hospital Zurich with major burn injuries compromising 20-80% of total body surface area. We compared two 3-year periods, one before the introduction of a goal-directed coagulation and transfusion algorithm (period 1: 2009-2011) and one after (period 2: 2016-2018). We applied linear and logistic regression models adjusted for confounders. We analyzed 36 patients (27.8% female) versus 42 patients (14.3% female) in period 1 and 2, respectively. Comorbidities and burn types were comparable between both collectives. Treatment according to the coagulation algorithm resulted in an overall reduction of 33 units of red blood cells (95% CI -52.8 to -12.9, p = 0.002), 9 units fresh frozen plasma (95% CI -14.7 to -2.6, p = 0.006) and 1.4g fibrinogen (95% CI -2.2 to -0.5, p = 0.001) per patient. We observed less infections (61.8% vs. 41.5%, p = 0.11) and a reduced mortality (38.9% vs. 26.8%, p = 0.33) during the algorithm treated period, although not significant. Treatment of severely burned patients with a goal-directed coagulation algorithm reduced blood product use and resulted in target-oriented administration of coagulation factors to improve outcomes

Changes in axonal excitability of primary sensory afferents with general anaesthesia in humans

BACKGROUND: Intraoperative monitoring of neuronal function is important in a variety of surgeries. The type of general anaesthetic used can affect the interpretation and quality of such recordings. Although the principal effects of general anaesthetics are synaptically mediated, the extent to which they affect excitability of the peripheral afferent nervous system is unclear. METHODS: Forty subjects were randomized in a stratified manner into two groups, anaesthetized with either propofol or sevoflurane. The threshold tracking technique (QTRAC(®)) was used to measure nerve excitability parameters of the sensory action potential of the median nerve before and after induction of general anaesthesia. RESULTS: Several parameters of peripheral sensory afferent nerve excitability changed after induction of general anaesthesia, which were similar for both propofol and sevoflurane. The maximum amplitude of the sensory nerve action potential decreased in both groups (propofol: 25.3%; sevoflurane: 29.5%; both P<0.01). The relative refractory period [mean (sd)] also decreased similarly in both groups [propofol: -0.6 (0.7) ms; sevoflurane: -0.3 (0.5) ms; both P<0.01]. Skin temperature at the stimulation site increased significantly in both groups [propofol: +1.2 (1.0)°C; sevoflurane: +1.7 (1.4)°C; both P<0.01]. CONCLUSIONS: Small changes in excitability of primary sensory afferents after the induction of anaesthesia with propofol or sevoflurane were detected. These effects, which were non-specific and are possibly explained by changes observed in temperature, demonstrate possible anaesthetic effects on intraoperative neuromonitoring

Preconditioning with sevoflurane decreases PECAM-1 expression and improves one-year cardiovascular outcome in coronary artery bypass graft surgery

BACKGROUND: Cardiac preconditioning is thought to be involved in the observed decreased coronary artery reocclusion rate in patients with angina preceding myocardial infarction. We prospectively examined whether preconditioning by sevoflurane would decrease late cardiac events in patients undergoing coronary artery bypass graft (CABG) surgery. METHODS: Seventy-two patients scheduled for elective CABG surgery were randomized to preconditioning by sevoflurane (10 min at 4 vol%) or placebo. For all patients, follow-up of adverse cardiac events was obtained 6 and 12 months after surgery. Transcript levels for platelet-endothelial cell adhesion molecule-1 (PECAM-1/CD31), catalase and heat shock protein 70 (Hsp70) were determined in atrial biopsies after sevoflurane preconditioning. RESULTS: Pharmacological preconditioning by sevoflurane reduced the incidence of late cardiac events during the first year after CABG surgery (sevoflurane 3% vs 17% in the placebo group, log-rank test, P=0.038). One patient in the sevoflurane group and three patients in the placebo group experienced new episodes of congestive heart failure and three additional patients had coronary artery reocclusion. Perioperative peak concentrations for myocardial injury markers were higher in patients with subsequent late cardiac events [NTproBNP, 9031 (4125) vs 3049 (1906) ng litre(-1), P&lt;0.001; cTnT, 1.31 (0.88) vs 0.46 (0.29) microg litre(-1), P&lt;0.001]. Transcript levels were reduced for PECAM-1 and increased for catalase but unchanged for Hsp70 in atrial biopsies after sevoflurane preconditioning. CONCLUSIONS: This prospective randomized clinical study provides evidence of a protective role for pharmacological preconditioning by sevoflurane in late cardiac events in CABG patients, which may be related to favourable transcriptional changes in pro- and antiprotective proteins