Der Anaesthesist
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Clinical Trial
[The NACA scale. Construct and predictive validity of the NACA scale for prehospital severity rating in trauma patients].
The NACA-scale is used in many Austrian, German and Swiss emergency medical systems for demographic description of emergency patients. Little attention has been payed to the evaluation of its construct and predictive validity. In 427 consecutive trauma patients rescued in primary mission the NACA-Scale and the Injury Severity Score (ISS) were determined. ⋯ The NACA-scale adequately describes life threat in trauma victims and correlates well with morbidity and mortality. Thus, it is a valuable tool for demographic purposes in emergency medical systems. For more precise prehospital severity rating in trauma patients, the NACA-scale should be supplemented or replaced by a physiologically based prehospital severity score.
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Clinical Trial
[Electric nerve stimulation in relation to impulse strength. A quantitative study of the distance of the electrode point to the nerve].
In the present study the difference of the distances of the tip of the needle to the nerve at similar current intensities but different pulse widths (100 microseconds vs. 1000 microseconds) were determined by means of 20 blockades of the sciatic nerve using the transgluteal approach of Labat. Comparable current intensities at different pulse widths (100 microseconds vs. 1000 microseconds) were compared in the same way, using the same position of the needle. At a pulse width of 100 microseconds and a current intensity of 0.30 mA, the tip of the needle is on an average of 5.0 mm closer to the nerve than with a pulse width of 1000 microseconds and a comparable current intensity of 0.28 mA (difference statistically highly significant; p < 0.005). ⋯ The success rate of the blockade was 95% at a current of 0.30 mA at 100 microseconds. Nerve lesions or other complications have not been seen. In conclusion, safe and successful nerve blocks in patients without polyneuropathia using the peripheral nerve stimulation seems to be obtained at a current intensity of about 0.30 mA at a pulse width of 100 microseconds.
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The alkali hydroxide content in soda lime induces Compound A formation from Sevoflurane (Sevo). This study was designed to answer the question if the use of potassium hydroxide-free Soda Lime (SL) would lead to lower Compound A levels as compared to Sodasorb (SO). A total of 30 patients scheduled for elective laparoscopic cholecystectomy received Sevo anaesthesia under low-flow conditions (0.8 l/min fresh gas flow). ⋯ Mean endtidal Sevo concentrations were 1.94 +/- 0.17 (SO) and 1.97 +/- 0.15 (SL) vol %, the total anaesthetic exposition was 1.52 +/- 0.36 (SO) and 1.64 +/- 0.47 (SL) MAC-h (n.s). The maximum Compound A concentration was significantly higher in SL group (19.6 +/- 2.8 vs. 11.7 +/- 4.1 ppm, p < 0.001). Therefore, elimination of potassium hydroxide from carbon dioxide absorbents alone did not lead to a reduction of Compound A formation during low-flow anaesthesia.