Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Apr 1979
Prevalence and prognostic significance of coma after cardiac arrest outside intensive care and coronary units.
In 181 patients resuscitated from cardiac arrest, the prevalence and duration of coma were registered and related to the site of occurrence of cardiac arrest, cardiac rhythm during arrest, age and clinical outcome of the patients. Coma was most frequent after cardiac arrest outside the hospital, as 84% of these patients were comatose for more than 1 h and 56% for more than 24 h; the corresponding values for patients with cardiac arrest in general wards were 63% and 30%, respectively, and for patients with cardiac arrest during ambulance transport, 80% and 44%. Permanent brain damage was extremely rare if the coma lasted less than 6 h (1 out of 62 patients), and relatively rare with a coma duration between 6 and 24 h (5 out of 34 patients). ⋯ Older patients were more vulnerable to coma than younger ones, but coma as such was not more frequent. We found no differences in coma after asystole and ventricular fibrillation. Problems concerning the selection of patients who have a chance of survival, although comatose after cardiac arrest, are discussed.
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Acta Anaesthesiol Scand · Feb 1979
In-line blood warming and microfiltration devices. I. Testing of flow and warming properties by pressure transfusion of aggregate-free blood.
Homogeneous microaggregate-free whole blood at +5 degrees C was transfused at constant pressures of 20 and 40 kPa through two micro-filtration and blood warming devices, and the temperature of the blood was recorded before it reached the venous cannula. The flow rates with the Fenwal system were 58 and 139 g/min, whereas the micro-filter MF10B combined with the Portex Coil allowed flow rates of 143 and 224 g/min. The warming capacities of the two warmers were almost equal and this did not prove to be their weak point. ⋯ Increasing the priming volume of the coil would raise the mean infusion temperature. A pressure infusor (Fenwal) was tested, and the internal pressures of the blood bag and the infusor were determined separately. The bag pressure differed significantly from the infusor pressure as the blood bag emptied, making the usefulness of the infusor manometer questionable.
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Acta Anaesthesiol Scand · Feb 1979
In-line blood warming and microfiltration devices. II. Influence of blood temperature on flow rate and hemolysis during pressure transfusion through microfilters and transfusion sets.
The influence of blood temperature on flow rate and hemolysis was studied. Homogeneous aggregate-free blood was transfused through six different microfilters and transfusion sets, combined with a large-bore venous cannula (Venflon No. 2) at a constant pressure of 20 kPa. Flow rates and plasma hemoglobin for cold (+5 degrees C) and prewarmed (+37 degrees C) blood were determined separately. ⋯ The Fenwal "dry-heat" warmer was found to have a great flow resistance. The pressure transfusion caused only a slight increase in free plasma hemoglobin of cold blood and no increase in prewarmed blood. It seems more practical to warm the entire blood unit before transfusion than to use so-called in-line blood warmers, because prewarming results in a flow rate approximately twice as high as that obtained with coils.
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Acta Anaesthesiol Scand · Jan 1978
Longitudinal spread of intraneurally injected local anesthetics. An experimental study of the initial neural distribution following intraneural injections.
Unexpected spinal anesthesia, occurring after peripheral nerve blocks close to the spine, may be caused by a centripetal spread of the local anesthetic along the injected nerve to the spinal cord. In order to analyze the pathway of such a spread, a radioactive local anesthetic mixed with a fluorescent dye was injected into difrerent compartments of the rabbit sciatic nerve, and the early distribution of these tracers was studied by scintillation counting and fluorescence microscopy. Epineurial (extrafascicular) injections were of low injection pressure (25-60 mmHg) (3.3-7.9 kPa) and limited spread, while endoneurial (intrafascicular) injections reached higher pressures (300-750 mmHg) (39.9-99.7 kPa) and caused a rapid spread over long distances within the fascicle. ⋯ However, 20% of endoneurial injections reached the spinal cord, where the injectate primarily spread in the thin subpial space. Our experimental findings suggest that intraneural injections of local anesthetics are responsible for the reported cases of unexpected spinal anesthesia due to inadvertent intrafascicular spread. Although intrafascicular injections are rarely made, we recommend that intraneural injections of local anesthetics or other solutions close to the spine should be avoided, as they may cause unexpected spinal anesthesia or lesion of the cord.
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Acta Anaesthesiol Scand · Jan 1978
Comparative StudyEEG-changes during general anaesthesia with enflurane (Efrane) in comparison with ether.
The effects of enflurane (efrane) and ether on the cerebral functions were studied by EEG on two similar groups of adult patients. For basic comparison a depth of anaesthesia was chosen which permitted abdominal surgery without the need to administer muscular relaxants. ⋯ If, however, the depth of anaesthesia was further increased, such EEG-changes indicating increased cerebral excitability were seen more often under enflurane and also appeared under ether anaesthesia. No seizure activity was recorded.