Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Motor signs of wakefulness during general anaesthesia with propofol, isoflurane and flunitrazepam/fentanyl and midlatency auditory evoked potentials (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Anaesthesia 49 (1994), S. 0 
    Details
    ISSN: 1365-2044
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Auditory evoked potentials have been used as an indicator of awareness. In the present study we combined epidural analgesia with three techniques of general anaesthesia. Motor signs of intra-operative wakefulness were documented and assessed along with cardiovascular changes and with midlatency auditory evoked potentials. Thirty patients undergoing elective laparotomy were studied as follows: first continuous epidural analgesia was used in all patients to block painful sensation to the level of T5. Intravenous general anaesthesia was induced with propofol (2.5 mg.kg-1 b.w., group 1, n = 10), thiopentone (5 mg.kg-1 b.w., group 2, n = 10) or etomidate (0.2 mg.kg-1 b.w., group 3, n = 10) and maintained with a propofol (3–5 mg.kg-1, group 1), isoflurane (0.4-0.8 Vol%, group 2), flunitrazepam and fentanyl (0.005 mg.kg-1 b.w.) bolus injection every 20 to 30 s (group 3). Heart rate and arterial pressure were recorded continuously. Purposeful movements of the limbs, eye-opening or other movements as well as coughing were documented as motor signs of intra-operative wakefulness. Auditory evoked potentials were recorded in the awake state, after induction and during maintenance of general anaesthesia. Motor signs of intra-operative wakefulness occurred statistically significantly more often in the patients of the flunitrazepam/fentanyl group than in those of the propofol and isoflurane group. There was no correlation between wakefulness and cardiocirculatory parameters. In the awake patients midlatency auditory evoked potentials had high peak to peak amplitudes and a periodic waveform. After induction of general anaesthesia with propofol, thiopentone and etomidate as well as during maintenance of general anaesthesia with propofol and isoflurane, midlatency auditory evoked potentials were severely attenuated or abolished. In contrast, during maintenance of general anaesthesia with flunitrazepam/fentanyl midlatency auditory evoked potentials reestablished high peak to peak amplitudes. The persistence of midlatency auditory evoked potentials coincides with a high incidence of motor signs of wakefulness. During the combination of regional and general anaesthesia, isoflurane and propofol seem to provide better suppression of motor signs of wakefulness than the intermittent bolus injection of flunitrazepam/fentanyl.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2044.1994.tb03516.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Midlatency auditory evoked potentials and purposeful movements after thiopentone bolus injection (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Anaesthesia 49 (1994), S. 0 
    Details
    ISSN: 1365-2044
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The effect of thiopentone on the middle latency auditory evoked potentials was investigated in 12 patients during induction of anaesthesia with thiopentone 5 mg.kg-1. 100% oxygen was administered throughout the induction, and when the patient moved purposefully a further bolus (2 mg.kg-1) was given, and anaesthesia continued in the normal way. The middle latency auditory evoked potentials were elicited before and during the induction. Binaural clicks (70 dB above normal hearing threshold) were presented at a rate of 9.3 per s. Averages of 1000 responses were analysed off line, and a fast Fourier transformation of the middle latency auditory evoked potentials were used to calculate the power spectrum of the averages. Awake, the patients had large peak to peak amplitudes and a normal waveform. The power spectra showed a high energy between 30-40 Hz. After induction the latencies of waves Na, Pa, Nb and PI and the amplitudes of the waves Na/Pa, Pa/Nb, and Nb/PI were decreased or completely attenuated. Both effects lasted for 4 min. When movement occurred (after 4–6 min), the values returned to awake. The second bolus repeated the changes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2044.1994.tb03362.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Power spectral analysis of the electroencephalogram during increasing end-expiratory concentrations of isoflurane, desflurane and sevoflurane (1998)
    Oxford : Blackwell Science Ltd, UK
    Anaesthesia 53 (1998), S. 0 
    Details
    ISSN: 1365-2044
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We studied the effects of increasing end-expiratory concentrations of isoflurane (0.3, 0.6, 0.9, 1.2 vol.%) (n = 12 patients), desflurane (1.5, 3.0, 4.5, 6.0 vol.%) (n = 12 patients) and sevoflurane (0.5, 1.0, 1.5, 2.0 vol.%) (n = 12 patients) on power spectral analysis of the electroencephalogram (EEG). Spectral edge frequency (SEF), total power (TP) and relative power in the delta, theta, alpha and beta band were calculated. EEG changes were very similar within the three groups. SEF decreased, TP and relative power in the delta and theta band increased, power in the beta band decreased in a dose-dependent fashion with comparable regression lines. This indicates that MAC equivalent administration of isoflurane, desflurane and sevoflurane in clinically applied dose ranges is associated with equipotent EEG suppression.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2044.1998.00332.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Effects of surgical stimulation on midlatency auditory evoked potentials during general anaesthesia with propofol/fentanyl, isoflurane/fentanyl and flunitrazepam/fentanyl (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Anaesthesia 49 (1994), S. 0 
    Details
    ISSN: 1365-2044
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: During general anaesthesia, midlatency auditory evoked potentials are suppressed in a dose dependent manner by a number of general anaesthetics. The activating effects of surgical stimuli on midlatency auditory evoked potentials have been demonstrated during light inhalational anaesthesia, and indicate that midlatency auditory evoked potentials reflect the activity of the central nervous system and not only anaesthetic concentrations. We investigated the effect of surgical stimulation (skin incision, sternotoniy) on midlatency auditory evoked potentials under high dose opioid analgesia in 30 patients undergoing elective cardiac surgery. High dose opioid analgesia was maititained using fentanyl (1.2 mg.h−1) and combined with either propofol (4-8 mg.kg−1.h−1) (group I, n = 10), isoflurane (0.6-1.2 vol%) (group II, n = 10) or flunitrazepam (1.2 mg.h−1) (group III. n = 10). Midlatency auditory evoked potentials were recorded in the awake state, during general anaesthesia before skin incision, after skin incision and after sternotoniy. During general anaesthesia there were marked statistically significant increases in latencies and decreases in amplitudes of midlatency auditory evoked potentials in the propofol/fentanyl and isoflurane/fentanyl groups. In contrast, in the flunitrazepam/fentanyl group there were only small changes of midlatency auditory evoked potentials. The latencies of the early cortical potentials were similar to those in the awake state. After skin incision as well as after sternotomy no significant changes of midlatency auditory evoked potentials could be observed in any of the experimental groups. These results indicate that activation of the auditory pathway by surgical stimuli may be blocked when analgesia is provided by high dose fentanyl. Furthermore, midlatency auditory evoked potentials may be preserved during surgical analgesia as demonstrated in the flunitrazepam/fentanyl group, whereas they were suppressed during propofol/fentanyl and isoflurance/fentanyl. Propofol (4-8 mg. kg−1.h−1) or isoflurane (0.6-1.2 vol%) seem to be superior to flunitrazepam (1.2 mg.h−1) in their potency to suppress the auditory pathway during surgical analgesia with fentanyl.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2044.1994.tb14222.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Anesthetic Control of 40-Hz Brain Activity and Implicit Memory
    Amsterdam : Elsevier
    Consciousness and Cognition 3 (1994), S. 129-147 
    Details
    ISSN: 1053-8100
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Psychology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1006/ccog.1994.1009
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Wachzustände während Allgemeinanästhesie Definition, Häufigkeit, klinische Relevanz, Ursachen, Vermeidung und medikolegale Aspekte (1995)
    Springer
    Der Anaesthesist 44 (1995), S. 743-754 
    Details
    ISSN: 1432-055X
    Keywords: Schlüsselwörter Intraoperative Wachheit ; Allgemeinanästhesie ; Key words Anaesthesia ; Intraoperative awareness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Abstract The possibility that a patient during general anaesthesia is aware of the operation going on and aware of severe pain that might be remembered postoperatively must be very alarming to patients and anaesthetists alike. Furthermore, there is experimental evidence showing that conscious recall of intraoperative events is only the tip of an iceberg; it seems very probable that there is even a higher incidence of unconscious perception during general anaesthesia. Therefore, the following stages of intraoperative awareness must be distinguished: (1) conscious awareness with explicit recall and with severe pain; (2) conscious awareness with explicit recall but no complaints of pain; (3) conscious awareness without explicit recall and possible implicit recall; (4) subconscious awareness without explicit recall and possible implicit recall; (5) no awareness. The incidence of conscious awareness with explicit recall and severe pain has been estimated at less frequent than 1/3000 general anaesthetics. Conscious awareness with explicit recall but no complaints of pain has been reported in the literature with an incidence of 0.5–2%. With 7–72%, conscious awareness without explicit recall and possible implicit recall shows a very wide range of variation and its occurrence probably depends on the anaesthetic drugs used. Subconscious awareness with possible implicit recall has an incidence of up to 80%, but there are many methodological problems in demonstrating implicit memory of intraoperative events. Reports of intraoperative awareness do not come exclusively from cardiac surgery and obstetrics, but also from all other operative specialities. Postoperatively, patients who experienced intraoperative awareness may develop a so-called post-traumatic stress syndrome. Symptoms involve re-experiencing the event awake or in dreams, sleep disturbances, depression, avoidance of stimuli associated with the event. The probability of the development of the post-traumatic stress syndrome seems to coincide with the experience of severe pain. When a patient complains of intraoperative awareness postoperatively the anaesthesiologist should discuss the event frankly with the patient. When the symptoms of the post-traumatic stress syndrome persist a psychotherapy should follow. Causes for intraoperative awareness may be: equipment failure, too-light anaesthesia, e.g. for a caesarean section or for emergency surgery in severely injured or polytraumatized patients, during cardiac surgery, bronchoscopy or difficult intubation. There is interindividual variability in anaesthetic effect; for example, chronic drug or alcohol abuse or overweight may make increased anaesthetic doses necessary. They are at risk for intraoperative awareness. Some general anaesthetics or anaesthetic procedures, e.g. the combination of a relaxant and N2O, opioid mono-anaesthetics, or opioids combined with benzodiazepines, seem to involve a higher risk of intraoperative awareness than do volatile anaesthetics. The bases of litigation are medical malpractice, breach of contract by the anaesthesiologist or lack of informed consent from the patient. Therefore, patients who are at risk of intraoperative awareness should be given detailed information on this special risk before the operation.
    Notes: Zusammenfassung Man unterscheidet verschiedene intraoperative Wachheitsstufen, wie explizit erinnerbare bewußte Wachheit und Erleben von Schmerz, explizit erinnerbare bewußte Wachheit ohne Schmerzerlebnis, bewußte Wachheit mit Amnesie, unbewußte Wachheit mit impliziter Erinnerung und keine Wachheit. Die explizit erinnerbare bewußte Wachheit mit Schmerzerleben wird auf〈1:3000 Allgemeinanästhesien geschätzt. Die erinnerbare bewußte Wachheit ohne Schmerz wird in der Literatur mit 0,2–2% angegeben. Mit 7–72% weist die bewußte Wachheit mit Amnesie in Abhängigkeit von den verwendeten Anästhesieverfahren eine weit größere Streuung auf. Unbewußte Wachheit mit postoperativer impliziter Erinnerung wird ebenso aufgrund methodischer Schwierigkeiten recht unterschiedlich mit bis zu 80% angegeben. Postoperativ kann sich nach einer intraoperativen Wachepisode beim Patienten ein sog. posttraumatisches Streßsyndrom entwickeln. Ursachen intraoperativer Wachheit können sein: Fehlfunktion der Narkosegeräte, die flache Allgemeinanästhesie wie bei Sectio caesarea, der akuten Versorgung des polytraumatisierten Patienten, während herzchirurgischer Operation, Bronchoskopie und bei erschwerter Intubation. Narkoseverfahren wie die alleinige Kombination von Relaxans und Lachgas, die alleinige Verabreichung von Opioiden und/oder Benzodiazepinen sind mit einer besonders hohen Inzidenz intraoperativer Wachheitsfälle belastet. Grundlagen für die gerichtlichen Schritte sind ärztliche Behandlungsfehler oder die nicht vorliegende Aufklärung und Einwilligung des Patienten für ein solches Ereignis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001010050209
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Anästhesie mit Flunitrazepam/Fentanyl und Isofluran/Fentanyl (1994)
    Springer
    Der Anaesthesist 43 (1994), S. 289-297 
    Details
    ISSN: 1432-055X
    Keywords: Schlüsselwörter: Allgemeinanästhesie – Bewußtes und unbewußtes Gedächtnis – Monitoring – Akustisch evozierte Potentiale ; Key words: General anaesthesia – Explicit and implicit memory – Monitoring – Auditory evoked potentials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Abstract. There is a high incidence of intraoperative awareness during cardiac surgery. Mid-latency auditory evoked potentials (MLAEP) reflect the primary cortical processing of auditory stimuli. In the present study, we investigated MLAEP and explicit and implicit memory for information presented during cardiac anaesthesia. Patients and methods. Institutional approval and informed consent was obtained in 30 patients scheduled for elective cardiac surgery. Anaesthesia was induced in group I (n=10) with flunitrazepam/fentanyl (0.01 mg/kg) and maintained with flunitrazepam/fentanyl (1.2 mg/h). The patients in group II (n=10) received etomidate (0.25 mg/kg) and fentanyl (0.005 mg/kg) for induction and isoflurane (0.6 – 1.2 vol%)/fentanyl (1.2 mg/h) for maintenance of general anaesthesia. Group III (n=10) served as a control and patients were anaesthetized as in I or II. After sternotomy an audiotape that included an implicit memory task was presented to the patients in groups I and II. The story of Robinson Crusoe was told, and it was suggested to the patients that they remember Robinson Crusoe when asked what they associated with the word Friday 3 – 5 days postoperatively. Auditory evoked potentials were recorded awake and during general anaesthesia before and after the audiotape presentation on vertex (positive) and mastoids on both sides (negative). Auditory clicks were presented binaurally at 70 dBnHL at a rate of 9.3 Hz. Using the electrodiagnostic system Pathfinder I (Nicolet), 1000 successive stimulus responses were averaged over a 100 ms poststimulus interval and analyzed off-line. Latencies of the peak V, Na, Pa were measured. V belongs to the brainstem-generated potentials, which demonstrates that auditory stimuli were correctly transduced. Na, Pa are generated in the primary auditory cortex of the temporal lobe and are the electrophysiological correlate of the primary cortical processing of the auditory stimuli. Results. None of the patients had an explicit memory of intraoperative events. Five patients in group I, one patient in group II, and no patients in group III showed implicit memory of the intraoperative tape message. They remembered Robinson Crusoe spontaneously when they were asked their associations with Friday. In the awake state AEP peak latencies were in the normal range. During general anaesthesia in group I, the peaks Na, Pa did not increase in latency or decrease in amplitude before and after the audiotape presentation. The primary cortical complex Na/Pa could be identified as in the awake state. In contrast, in group II Na, Pa showed a marked increase in latency and a decrease in amplitude or were completely suppressed. Conclusions. During general anaesthesia auditory information can be processed and remembered postoperatively by an implicit memory function, when the electrophysiological conditions of primary cortical stimuli processing is preserved. Implicit memory can be observed more often when high-dose opioid analgesia is combined with receptor-binding agents like the benzodiazepines than under non-specific anaesthetics like isoflurane. Non-specific anaesthetics seem to provide a more effective suppression of auditory stimuli processing than receptor-specific agents.
    Notes: Zusammenfassung. Die Inzidenz intraoperativer Wahrnehmungen ist bei herzchirurgischen Eingriffen besonders hoch. In der vorliegenden Studie sollten explizite und implizite Erinnerungen an intraoperative Information untersucht und zu akustisch evozierten Potentialen mittlerer Latenz (AEPML) in Beziehung gesetzt werden. Untersucht wurden 30 Patienten, die sich einer elektiven aortokoronaren Bypassoperation unterziehen mußten. Bei den Patienten der Gruppe I (n=10) wurde die Anästhesie mit Flunitrazepam/Fentanyl (0,01/0,01 mg/kg) eingeleitet und mit Flunitrazepam/Fentanyl (1,2 mg/h) aufrechterhalten. Die Patienten der Gruppe II (n=10) erhielten zur Einleitung Etomidat (0,25 mg/kg) und Fentanyl (0,005 mg/kg) und zur Narkoseaufrechterhaltung Isofluran (0,6 – 1,2 Vol.-%) und Fentanyl (1,2 mg/h). Die Gruppe III (n=10) diente als Kontrollgruppe, in der die Anästhesie wie bei I oder II durchgeführt wurde. Nach der Sternotomie wurde den Patienten der Gruppen I und II ein Tonbandtext vorgespielt, der eine implizite Gedächtnisaufgabe enthielt. Den Patienten der Gruppe III wurde kein Tonband vorgespielt. Explizite und implizite Erinnerungen wurden 3 – 5 Tage postoperativ abgefragt. Die Ableitung der AEPML erfolgte wach, vor und nach Tonbandeinspielung. Kein Patient hatte eine explizite Erinnerung an intraaoperative Ereignisse. Als Ausdruck einer unbewußten, impliziten Gedächtnisfunktion erinnerten 5 Patienten der Gruppe I, 1 Patient der Gruppe II und kein Patient der Gruppe III das intraoperativ dargebotene Zielwort. Die AEP der wachen Patienten zeigten normale Latenzen der Gipfel V, Na, Pa. Während Anästhesie, vor und nach Tonbandeinspielung waren bei den Patienten der Gruppe I die Latenzen Na, Pa nur geringfügig verlängert. Bei den Patienten der Gruppe II waren vor und nach Tonbandeinspielung die Latenzen Na, Pa erheblich verlängert. Während Anästhesie kann es zur Aufnahme und Verarbeitung akustischer Information kommen, die postoperativ unbewußt erinnert werden kann. Diese ist häufiger während Anästhesie mit Benzodiazepinen und Opioiden, unter denen die primäre akustische Reizverarbeitung weitgehend erhalten ist, nachweisbar, als unter der Kombination von Isofluran und Opioiden, bei der die primäre auditive Reizverarbeitung unterdrückt ist.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001010050060
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Monitoring intraoperativer Wachzustände Vegetative Zeichen, isolierte Unterarmtechnik, Elektroenzephalogramm und akustisch evozierte Potentiale (1996)
    Springer
    Der Anaesthesist 45 (1996), S. 708-721 
    Details
    ISSN: 1432-055X
    Keywords: Schlüsselwörter Allgemeinanästhesie: intraoperative Wachzustände ; Monitoring: isolierte Unterarmtechnik ; Elektroenzephlogramm ; akustisch evozierte Potentiale ; Key words Anaesthesia ; general ; Intraoperative awareness ; Monitoring: isolated forearm technique ; Electroencephalogram ; Auditory evoked potentials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Abstract Several methods have been developed to quantify central anaesthetic effects and monitor awareness during general anaesthesia. The most important of these are the PRST score, calculated from changes in blood pressure, heart rate, sweating, and tear production, the isolated forearm technique, where the patient is allowed to move during surgery, the processed electroencephalogram (EEG) and the derived parameters median frequency (MF) and spectral-edge frequency (SEF), and midlatency auditory evoked potentials (MLAEP). In clinical practice, the application of individual doses of anaesthetics is generally guided by autonomic vegetative clinical signs such as changes in blood pressure, heart rate, sweating, and tear production, quantified as the PRST score. Unfortunately, these parameters are not very reliable with regard to predicting the suppression of consciousness and awareness, especially when high-dose opioids are used in patients with cardiovascular medications and a variety of accompanying diseases. The PRST score probably indicates mainly the autonomic responses to painful stimuli, and seems to be useful in guiding the individual use of analgesics. The isolated forearm technique is a useful test of the patient's responsiveness during general anaesthesia, and thus an instrument for investigating the incidence of awareness during different anaesthetic regimens and when muscle relaxants are imployed. A disadvantage is that it can only be used for 20 to 30 min because of pressure-induced nerve blocks or lesions. It can not be employed when long-term relaxation is necessary and consciousness and awareness are to be monitored continuously. The processed EEG and the derived parameters MF and SEF are important scientific tools to quantify central effects of many anaesthetics and opioid analgesics that allow the development of pharmacodynamic-pharmacokinetic models of anaesthetic action. MF has proven to be useful in monitoring closed-loop feedback of intravenous drug administration. Unfortunately, until now there have been no clinical studies that document the usefulness of MF or SEF with regard to predicting intraoperative arousal or awareness. To the contrary, some experimental data failed to predict imminent arousal and response to surgical incision or verbal commands by MF or SEF. Therefore, the EEG seems to be of limited value for monitoring awareness, consciousness, or memory formation during anaesthesia. MLAEP are suppressed in a dose-dependent fashion by many general anaesthetics and correlate with wakefulness, awareness, and explicit and implicit memory during anaesthesia and seem to be a promising method of monitoring awareness during anaesthesia. Nevertheless, future studies will have to determine threshold values for the different MLAEP parameters for intraoperative awareness and explicit and implicit recall of intraoperatively presented information for the different commonly used anaesthetics. Only then will it be possible to determine the usefulness of the method in clinical practice.
    Notes: Zusammenfassung Es sind verschiedene Methoden entwickelt worden, um Wachzustände während Allgemeinanästhesie zu erfassen. Die wichtigsten sind der PRST-Score, der aus Veränderungen von Blutdruck, Herzfrequenz, Schweißsekretion und Tränenfluß errechnet wird, die isolierte Unterarmtechnik, das verarbeitete EEG sowie die akustisch evozierten Potentiale mittlerer Latenz. Der PRST-Score erscheint nicht sehr verläßlich, um intraoperative Wachzustände anzuzeigen. Die isolierte Unterarmtechnik kann nur kurzzeitig angewendet werden. Das verarbeitete EEG, vor allem die abgeleiteten Parameter Medianfrequenz und spektrale Eckfrequenz sind wichtige wissenschaftliche Instrumente, um zentrale Anästhetikaeffekte zu quantifizieren. Mit ihrer Hilfe sind pharmakodynamische-pharmakokinetische Modelle entwickelt worden. Sie erscheinen jedoch weniger geeignet, um intraoperative Wachzustände anzuzeigen. Die akustisch evozierten Potentiale mittlerer Latenz sind unter einer Vielzahl von Anästhetika dosisabhängig unterdrückt. Sie korrelieren mit Wachzuständen während Narkose, expliziten und impliziten Gedächtnisfunktionen nach Anästhesie. Sie erscheinen als vielversprechende Methode, um intraoperative Wachzustände zu erfassen. Zukünftige Studien werden Schwellenwerte der verschiedenen Parameter der akustisch evozierten Potentiale für intraoperative Wachzustände, explizite und implizite Erinnerungen an intraoperativ präsentierte Information für verschiedene Anästhetika zu bestimmen haben. Erst dann wird man definitiv die Brauchbarkeit der Methode im klinischen Alltag bewerten können.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001010050303
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Akustisch evozierte Potentiale mittlerer Latenz während Anästhesie mit Sufentanil (1995)
    Springer
    Der Anaesthesist 44 (1995), S. 478-482 
    Details
    ISSN: 1432-055X
    Keywords: Schlüsselwörter Allgemeinanästhesie ; Sufentanil ; Akustisch evozierte Potentiale ; Key words Anaesthesia: general ; Anaesthetics: sufentanil ; Auditory evoked potentials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Abstract Patients and methods. We have studied mid-latency auditory evoked potentials (MLAEP) during general anaesthesia with sufentanil in ten patients scheduled for elective major urological surgery. Anaesthesia was induced with sufentanil 2–3 μg/kg; for maintenance of anaesthesia a further bolus of sufentanil (1–2 μg/kg) 10 min before the start of surgery (skin incision) was given. MLAEP were recorded before and 10 min after the last sufentanil bolus on the vertex (positive) and mastoids on both sides (negative). Latencies of the peaks V, Na, Pa, Nb, and P1 (ms) and amplitudes Na/Pa, Pa/Nb, and Nb/P1 (μV) were measured. Results. In the awake state, MLAEP had high peak-to-peak amplitudes and a periodic wave form. During general anaesthesia with sufentanil the brainstem response V was stable. There was a marked increase in latency and a decrease in the amplitude of Nb and P1. In contrast, for the early cortical potentials Na and Pa only small increases in latencies and decreases in amplitudes were observed. Na and Pa showed a similar pattern to that in awake patients. Conclusions. There is no substantial difference of sufentanil's effect on MLAEP compared with the opioids alfentanil, fentanyl, and morphine. Because Na, Pa, and Nb are generated in the primary auditory cortex of the temporal lobe, it must be concluded that during general anaesthesia with sufentanil primary cortical processing of auditory stimuli may be preserved.
    Notes: Zusammenfassung Wir untersuchten akustisch evozierte Potentiale mittlerer Latenz während Allgemeinanästhesie mit Sufentanil bei 10 Patienten, die sich einer größeren elektiven urologischen Operation unterziehen mußten. Die Narkose wurde mit Sufentanil (2–3 μg/kg KG) eingeleitet, vor Operationsbeginn wurde ein weiterer Bolus Sufentanil (1–2 μg/kg KG) nachinjiziert. Die akustisch evozierten Potentiale wurden im Wachzustand und 10 min nach der letzten Sufentanil-Bolusgabe vor Beginn der Operation (Hautschnitt) abgeleitet. Identifiziert wurden die Gipfel V, Na, Pa, Nb, P1 (ms) und die Amplituden Na/Pa, Pa/Nb und Nb/P1 (μVolt) vermessen. Im Wachzustand hatten die akustisch evozierten Potentiale hohe Amplituden und einen periodischen Erregungsablauf. Während Allgemeinanästhesie mit Sufentanil war die Antwort des Gehirnstamms stabil. Eine deutliche Latenzzunahme und Amplitudenreduktion zeigte sich für die späten Gipfel Nb und P1. Im Gegensatz hierzu waren die frühen kortikalen Potentiale Na und Pa nur geringgradig in Latenz und Amplitude verändert. Sie konnten ähnlich wie im Wachzustand abgeleitet und identifiziert werden. Diese Beobachtungen entsprechen experimentellen Befunden unter anderen Opioiden (Alfentanil, Fentanyl und Morphin).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001010050179
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...