Ion mobility spectrometry coupled to a multi-capillary column (MCC/IMS) was used in anesthesia to detect signals related to Propofol in the breath directly. First time both positive and negative ions were investigated. It was found, that the detection limit in the negative mode is lower as in the positive one. Results of experiments with and without a bolus of Propofol were discussed with respect to kinetic models.

Background. In the present investigation we compared the consumption of desflurane (DES) and isoflurane (ISO) using a standardized minimal flow protocol with a forced reduction of the fresh gas flow (FGF).Methods. 54 adult women were examined. After induction of anaesthesia a forced reduction of the FGF was started: 5 min 0.5 l/min O-2 + 1 l/min N2O, 10 min 0.5 l/min O-2 + 0.5 l/min N2O; finally 0.3 l/min O-2 + 0.2 l/min N2O up to the end of surgery. The consumption of DES/ISO was determined with a precision balance.Results. In the DES group the uptake was around 0.3 Vol.-%, i.e. less than 8% of the target 2/3-MAC value was taken up. For ISO the uptake was around 0.25 Vol.-%, i.e. approximately 30% of the target 2/3-MAC value. The DES consumption was after 60 min 17.0 +/- 1.1 g, 120 min 27.3 +/- 1.8 g and 180 min 36.5 +/- 1.7 g. ISO consumption was significantly lower: 7.6 +/- 0.8 g, 12.4 +/- 1.7 g and 15.5 +/- 1.6 g. The use of DES yielded higher costs, i.e. 2.28 EURO for 60 min, 3.63 EURO for 120 min and 4.97 EURO for 180 min. The consumption of the inhaled anaesthetics can be calculated as: DES (g) = 4.84 + 0.184 x duration (min) (R-2 = 0.981), ISO (g) = 2.049 + 0.0826 x duration (R-2=0.979). The costs are: DES (EURO) = 0.85 + 0.0323 x duration (min); ISO (EURO) = 0.19 + 0.0077 x duration (min).Conclusion. With a forced reduction of the FGF the DES consumption is still higher.

Knoll, H.1; Schreiber, J. U.1; Ziegeler, S.1; Buchinger, H.1; Semyonov, K.1; Bialas, P.1; Larsen, R.1; Mencke, T.2 Author Information

Desfluran lässt aufgrund seiner pharmakokinetischen Eigenschaften ein rasches Einwaschverhalten erwarten: Schnelle und mittelschnelle Körperkompartimente werden zügig aufgesättigt, sodass der Desfluranbedarf nach Abschluss der Einwaschphase im weiteren Verlauf nur noch gering ist. In der vorliegenden Arbeit wurde untersucht, ob der Desfluranverbrauch durch eine konsequente Reduktion des Frischgasflusses bei Anästhesieeinleitung so weit vermindert werden kann, dass sich die Substanzkosten von Desfluran und Isofluran angleichen.

BACKGROUND:Sepsis may lead to the suppression of stimulated cytokine release after Gram-negative stimuli, correlating with a fatal outcome. Treatment of sepsis includes adequate therapy with antibiotics. The aim of this study was to investigate the role of antibiotics in the modulation of the lipopolysaccharide (LPS)-stimulated cytokine response of human monocytes.METHODS:In this ex vivo, in vitro study, whole blood samples were taken from 10 healthy volunteers, stimulated with LPS in the presence or absence of various antibiotics (penicillin, amoxicillin, cefuroxime, ceftazidime, cefotaxime, piperacillin/tazobactam, imipenem/cilastatin, gentamicin, netilmicin, ciprofloxacin, vancomycin) and cultured for 24 h. Thereafter, tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) were measured in the supernatants by enzyme-linked immunosorbent assay (ELISA). Furthermore, CD14 and HLA-DR expression on monocytes was assessed using flow cytometry.RESULTS:All cephalosporins decreased LPS-stimulated IL-10 release. Cefuroxime and cefotaxime also decreased the expression density of the LPS recognition molecule CD14 on monocytes. An increase in LPS-stimulated IL-10 release was observed with vancomycin. A suppression of LPS-stimulated TNF-alpha and IL-10 release was observed in the presence of ciprofloxacin.CONCLUSION:These results indicate a modulation of the expression density of CD14 on monocytes, together with a shift from a balanced to an inflammatory cytokine release pattern, by cefuroxime and cefotaxime. Vancomycin changes the response to an anti-inflammatory release pattern. After ciprofloxacin, a profound unresponsiveness of immune-competent cells to LPS stimulation is observed. Because of the critical role of a balanced innate immune response, these data may be of importance for the selection of antibiotics in septic patients.

Autoregressive modeling with exogenous input of middle-latency auditory evoked potentials (A-Line AEP index, AAI) has been developed for monitoring depth of anesthesia. We investigated the prediction of recovery and dose-response relationship of desflurane and AAI or bispectral index (BIS) values. Twenty adult men scheduled for radical prostatectomy were recruited. To minimize opioid effects, analgesia was provided by a concurrent epidural in addition to the general anesthetic. Electrodes for AAI and BIS monitoring and a headphone for auditory stimuli were applied. Propofol and remifentanil were used for anesthetic induction. Maintenance of anesthesia was with desflurane only. For comparison to AAI and BIS monitor parameters, pharmacokinetic models for desflurane and propofol distribution and effect-site concentrations were used to predict clinical end-points (Prediction probability P(K)). Patients opened their eyes at an AAI value of 47 +/- 20 and a BIS value of 77 +/- 14 (mean +/- sd), and the prediction probability for eye opening was P(K) = 0.81 for AAI, P(K) = 0.89 for BIS, and P(K) = 0.91 for desflurane effect-site concentration. The opening of eyes was best predicted by the calculated desflurane effect-site concentration. The relationship between predicted desflurane effect-site concentration versus AAI and BIS was calculated by nonlinear regression analysis (r = 0.75 for AAI and r = 0.80 for BIS). The correlation between BIS and clinical end-points of anesthesia or the desflurane effect-compartment concentration is better than for the AAI.

Ziegeler, S.; Buchinger, H.; Fink, T.; Stoll, S.; Christmann, T.; Rensing, H.; Larsen, R. Author Information

Reduction of the perioperative cardiovascular risk with pharmacological interventions plays a prominent role in routine anesthesia practice. For example, perioperative beta-blockade is well established in anesthesiological treatment of patients. There is a growing body of evidence supporting the cardioprotective effects of volatile anesthetics known as anesthetic-induced preconditioning. There are numerous and complex data from animal studies. The mechanisms of anesthetic-induced preconditioning have been extensively studied but have still not been clearly identified. Initial clinical data show the cardioprotective effects of volatile agents by looking at parameters of myocardial function and laboratory values and therefore, the question of the relevance of these data for routine clinical practice has been raised. This review gives a summary of the currently available data focusing on the mechanisms of anesthesiological preconditioning and clinical studies.

Buchinger, H.; Kreuer, S.; Ziegeler, S.; Schröder, M.; Larsen, R.; Wilhelm, W. Author Information

Die Minimierung des perioperativen kardiovaskulären Risikos durch medikamentöse Interventionen spielt in der Anästhesie eine wichtige Rolle. So hat z. B. die Therapie mit β-Blockern inzwischen einen festen Stellenwert in der perioperativen anästhesiologischen Behandlung erlangt. In der Literatur gibt es eine zunehmende Fülle an Hinweisen auf einen myokardprotektiven Effekt der volatilen Anästhetika. Dieses Phänomen wird mit dem Begriff der anästhetikainduzierten Präkonditionierung (AP) beschrieben. Tierexperimentelle Daten sind vielfältig und komplex. Die Mechanismen der anästhetikainduzierten Kardioprotektion wurden eingehend untersucht, sind aber letztlich nicht abschließend geklärt. Auch erste klinische Daten belegen einen protektiven Effekt der inhalativen Anästhetika anhand von myokardialen Funktions- und Schädigungsparametern. Daher stellt sich für den klinisch tätigen Anästhesisten die Frage einer praktischen Relevanz für die Narkoseführung bei Patienten mit entsprechendem Risikoprofil. Die vorliegende Arbeit gibt einen Überblick über die derzeitigen wissenschaftlichen Ergebnisse mit einer Fokussierung auf die Mechanismen der anästhesiologischen Präkonditionierung und auf klinische Untersuchungen.

In der vorliegenden Untersuchung wurde die Geschlechtsabhängigkeit von Propofolverbrauch und Aufwachzeiten nach Propofol-Remifentanil-Anästhesie bei standardisierter Anästhesietiefe untersucht.

Buchinger, H.; Kreuer, S.; Bruhn, J.; Wrobel, M.; Bauer, C.; Wilhelm, W. Author Information

A common side effect associated with succinylcholine is postoperative myalgia. The pathogenesis of this myalgia is still unclear; inflammation has been suggested but without convincing evidence. We designed the present study to investigate whether an inflammatory reaction contributes to this myalgia. The incidence and severity of succinylcholine-associated myalgia was determined in 64 patients pretreated with saline or dexamethasone before succinylcholine (n = 32 for each). Incidence and severity of myalgia did not differ significantly between the two groups: 15 patients in the dexamethasone group complained of myalgia compared with 18 patients in the saline group, and severe myalgia was reported by five patients and three patients, respectively (not significant). At 48 h after surgery, 12 patients in both groups still suffered from myalgia (not significant). In addition, interleukin-6 (IL-6) as an early marker of inflammation was assessed in a subgroup of 10 patients pretreated with saline. We found an increase of IL-6 for only three patients, but only one patient reported myalgia; no relationship between myalgia and the increase of IL-6 was found. In conclusion, there is no evidence for an inflammatory origin of succinylcholine-associated myalgia. IMPLICATIONS: Administration of dexamethasone before succinylcholine was not effective in decreasing the incidence or the severity of succinylcholine-induced postoperative myalgia. Furthermore, there was no significant relationship between postoperative myalgia and time course of interleukin-6 concentrations, a marker of inflammation. Pretreatment with dexamethasone is not justified to prevent postoperative myalgia after succinylcholine.

Background: Cardiopulmonary bypass (CPB) induces a systemic inflammatory reaction. Microcirculation‐dependent alteration of the gut mucosal barrier with subsequent translocation of endotoxins is a postulated mechanism for this inflammatory response. This study was designed to elucidate whether two different approaches to modulate splanchnic perfusion may influence systemic inflammation to CPB. Methods: We examined 40 patients scheduled for elective coronary bypass surgery in a prospective, randomized study. One group (DPX) received dopexamine (1 µg · kg −1 · min −1 ) continuously after induction of anesthesia until 18 h after CPB. The control group (CON) received equal volumes of NaCl 0.9% in a time‐matched fashion. In a third group (EPI) a continuous epidural infusion of bupivacaine 0.25% [(body height (cm) – 100) · 10 −1 =ml·h −1 ] was administered for the whole study period. Procalcitonin (PCT), tumor necrosis factor (TNF‐α), soluble TNF receptor, human soluble intercellular adhesion molecule‐1, C‐reactive protein (CRP) and leukocyte count were measured as parameters of inflammation. Results: All parameters significantly increased following CPB. Increases of PCT, TNF‐α and leukocyte count were significantly attenuated in the DPX and EPI groups at different time points. However, neither splanchnic blood flow nor oxygen delivery and consumption were different when compared with the CON‐group. Conclusion: These results do suggest that mechanisms other than an improved splanchnic blood flow by DPX and EPI treatment have to be considered for the anti‐inflammatory effects.