Beschreibung:
HintergrundDie Gabe von Opioiden zur Schmerzunterdrückung spielt eine zentrale Rolle in der modernen Anästhesiologie. Messungen von Hypnosetiefe und Muskelrelaxierung sind im Gegensatz zur Schmerzmessung seit Jahren etabliert. Seit Kurzem ist das PMD200 („Pain Monitoring System“; Fa. Medasense Biometrics™ Ltd., Ramat-Gan, Israel) verfügbar. Dieser Schmerzmonitor misst nichtinvasiv und errechnet einen dimensionslosen Schmerzindex („nociceptor level“, NoL). Die Validität und Zuverlässigkeit des Verfahrens sind Gegenstand von klinischen Studien.FragestellungReduziert die Verwendung des PMD200 die Gabe von Analgetika während einer Da-Vinci-Prostatektomie?Material und MethodenIn die Studie wurden 50 Patienten aufgenommen. Nach gewichtsadaptierter Sufentanilgabe zur Narkoseinduktion und einem 10 µg Bolus vor Hautschnitt erfolgte die intraoperative Analgesie durch subjektive Entscheidung (CONT) oder aufgrund eines erhöhten NoL-Index (INT). Die statistische Auswertung erfolgte durch Mann-Whitney-U-, Kolmogorow-Smirnow-Test und Levene-Statistik.ErgebnisseIn der INT-Gruppe war die Anzahl der Sufentanilboli/h nicht signifikant geringer als in der CONT-Gruppe (p = 0,065). Die Varianz der Sufentanilgaben unterschied sich signifikant (p = 0,033). In der CONT-Gruppe war die Applikation normal verteilt (p = 0,2), in der INT-Gruppe hingegen nicht (p = 0,003).DiskussionEine mögliche Interpretation der Daten ist, dass die Schmerzmittelgabe in der INT-Gruppe individualisierter erfolgte, d. h., es wurden nichterforderliche Schmerzmittelgaben vermieden, und gleichzeitig detektierte das NoL-Monitoring einzelne Patienten mit deutlich erhöhtem Schmerzmittelbedarf. Diese Schlussfolgerung ist nur unter der Voraussetzung zulässig, dass das PMD200 auch tatsächlich die Entität Schmerz misst. ; BackgroundAdministration of opioids to suppress pain plays a major role in modern anesthesia. Measuring depth of hypnosis and neuromuscular recovery are already well established, and devices for pain monitoring are available. Nonetheless pain monitoring is rare in clinical practice. Recently, the pain monitoring device PMD200 (Medasense Biometrics™ , Israel) was introduced. It non-invasively measures heart rate, heart rate variability, skin resistance, resistance variability, temperature and movement to calculate a nociception level (NoL) index. The NoL index range starts at zero, which is equivalent to being painless, and goes up to a value of 100. The validity and reliability of NoL monitoring is the content of current studies.ObjectiveWe tested the hypothesis if the use of the PMD200 significantly reduces opioid consumption during da Vinci prostatectomy.Material and methodsA total of 50 male patients were included in this randomized, single blinded study. Exclusion criteria were arrhythmia because the pain monitoring device requires a sinus rhythm for reliable results. Patients received a weight-adjusted sufentanil bolus (0.3 µg/kg ideal body weight) during induction of anesthesia. Additionally, they received 10 µg of sufentanil before skin incision. Both groups received total intravenous anesthesia with propofol and continuous muscle relaxation through cis-atracurium.In the control group (CONT; n = 26), a standardized sufentanil bolus of 10 µg were administered by common criteria (heart rate/blood pressure increase, lacrimation, gut feeling) at the anesthesiologistʼs discretion. In the intervention group (INT; n = 24), patients received the standardized sufentanil bolus when the NoL index was above 25 for 2 min, which corresponds to the manufacturerʼs recommendation. The NoL index and bolus administrations were recorded for every patient. In the control group, the display of the pain monitor showing the NoL index was not visible for the anesthesiologist. Postoperatively, pain/nausea scores and piritramide consumption were taken every 10 min for 1h in the recovery room. None of the patients had prior chronic pain with long-term use of painkillers.Statistics were done using Mann-Whitney U‑test, Kolmogorov-Smirnov test and Levene test.ResultsSufentanil bolus administrations, normalized for duration of surgery, were not significantly lower in the intervention group (p = 0.065). We noticed a significant difference in variation of opioid administrations (p = 0.033). Sufentanil boluses per hour in the INT were normally distributed (p = 0.2), whereas in CONT they were not (p = 0.003). Postoperative data like nausea, opioid consumption and pain scale showed no differences between groups.ConclusionThe use of PMD200 did not significantly reduce cumulative opioid consumption. Following on we must reject the initial hypothesis. The difference in sufentanil bolus variances may point to an individualized antinociceptive therapy when NoL monitoring is used. We suppose patients with high opioid demands are detected and patients with low opioid demands did not receive unnecessary opioids. This assumption is only true if the PMD200 measures the entity pain. Further studies with more participants during surgery with higher tissue damage could lead to more convincing data and conclusions.