Der Anaesthesist
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In 1977 a new anaesthesiology preoperative evaluation clinic was started for evaluation of all elective surgical patients for their fitness to undergo anaesthesia. Physical examination, medical history and anaesthetic risk assessment are assessed in a standardized manner with the aid of computer menus. Comprehensive laboratory tests included electrocardiography, lung function assessment (vital capacity and forced exspiratory volume within 1 s), chest X-ray, and arterial blood gas analysis and blood chemistry analysis with an SMA-22 (System Multi Analyzer). ⋯ We found that perioperative complications and adverse outcome correlated with preoperative data and physical examination. The main source of perioperative morbidity and mortality was the cardiovascular system, followed by nephrologic diseases, correlating exactly with preoperative BUN and plasma creatinine. These studies also underlined the value of the ASA physical status to predict perioperative outcome.(ABSTRACT TRUNCATED AT 250 WORDS)
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Despite a widespread approach to explain the molecular mechanisms of anaesthetic agents, the complex state of "general anaesthesia" is still not completely understood. Voltage-activated sodium channels from human brain cortex served as a model membrane protein to investigate anaesthetic drug-protein interactions using a novel electrophysiological voltage-clamp technique. Sodium channels are already well-characterized important integral membrane proteins responsible for the generation of the fast-propagated action potential and thus are vital components for neuronal signal integration and cell communication. In order to elucidate the molecular interactions of intravenous anaesthetics with single human brain sodium channels, representative compounds of four different clinical intravenous anaesthetic groups were used to correlate different types of clinical anaesthesia with differential anaesthetic effects on the molecular level. METHODS. Single sodium channels from human brain cortex were incorporated into artificial phospholipid bilayers and studied under our standard experimental conditions (Electrolyte solution: 500 mM NaCl, 10 mM HEPES, pH 7.4, Temp. 22-25 degrees C) with an electrophysiological voltage-clamp technique. In the presence of a channel activator (1 microM batrachotoxin) single-channel characteristics (fractional open time, single-channel conductance and amplitude, steady-state activation behaviour) were characterized for control conditions and in the presence of various doses of four different anaesthetic agents (pentobarbital, propofol, ketamine, midazolam). RESULTS. During control measurements the investigated human brain sodium channels showed stable and reproducible characteristics on the range expected for batrachotoxin-modified sodium channels in bilayers. After completion of the control measurement the effects of the four different general anaesthetics pentobarbital, propofol, ketamine and midazolam were investigated on the same control sodium channels. All four substances demonstrated a blocking effect of sodium channel conductance (pentobarbital: K50: concentration for 50% block of the maximal conductance block: 0.69 mM; blockmax: maximal conductance block (%): 100%; propofol: K50: 0.02 mM, blockmax: 28%; ketamine: K50: 1.1 mM, blockmax: 71%; midazolam: K50: 0.52 mM, blockmax: 100%). Furthermore, a destabilization of the steady-state activation process could be demonstrated. These effects were dose dependent, but only pentobarbital and propofol demonstrated these effects at or near clinically relevant serum concentrations. ⋯ At the clinical level, "general anaesthesia" is a highly complex phenomenon. Similarly, anaesthetics may demonstrate a multimechanistic mode of action also at the molecular level. In this study all four investigated anaesthetic compounds interacted with at least two primary sodium channel functions, leading to a voltage-independent reduction of the fractional channel open time and an interaction with the steady-state activation behaviour, respectively. The effects of pentobarbital and propofol were detectable at concentrations within the range of serum concentrations achieved during clinical anaesthesia, whereas ketamine and midazolam demonstrated qualitatively similar effects exceeding this range 10- to 50-fold. Thus, the human brain sodium channel might serve as a molecular target only for pentobarbital and propofol. This suggests that different types of clinical anaesthesia may correlate with differential actions of anaesthetics on the molecular level.
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Documentation of physician-staffed ambulance runs traditionally focuses on information transfer between the prehospital care provider and the receiving hospital. To use this information as a tool for research and quality assurance programs, the German Interdisciplinary Association of Critical Care Medicine developed in a consensus process a protocol for nationwide use. Protocol development was based on the question of what information can be obtained reliably in the emergency medical service (EMS) environment and what questions should be answered by data analysis. ⋯ For data collection, the concepts of manual processing versus optical scanning are evaluated. The data analysis can serve as a basic tool for screening structure and process quality of EMS systems on a local as well as a nationwide level. During this process, areas for improvement as well as for clinical research are identified.
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Randomized Controlled Trial Clinical Trial
[The effect of thoracic epidural anesthesia on the pathophysiology of the eventration syndrome].
Abdominal mesenteric traction (MT) results in decreased mean arterial pressure (MAP), systemic vascular resistance (SVR) and increased cardiac output (CO). This response is induced by a considerable release of prostacyclin (PGI2). Precipitous falls in systemic arterial pressure related to central and/or autonomic nervous reflex arcs also have been described during operations on the upper abdominal viscera. ⋯ Our data clearly indicate that the mesenteric traction response consists in relevant haemodynamic alterations and a significant decrease of paO2. Stable haemodynamics and paO2 following cyclooxygenase inhibition signify an action mediated by prostacyclin. Deafferentation of the splanchnic nerves by supplementary thoracic epidural anaesthesia did not influence either prostacyclin release or the decrease in blood pressure and paO2 after traction on the mesentery root...