[Patient-centered perioperative vigilance: perioperative process quality, effectiveness of pain treatment and mobilization progress after implementation of a treatment bundle for total knee endoprosthesis]. / Patient*innenzentrierte perioperative Versorgung: perioperative Prozessqualität, Effektivität von Schmerztherapie und Mobilisationsfortschritt nach Implementation eines Maßnahmenbündels bei Knietotalendoprothese.

BACKGROUND: The perioperative surgical home is a patient-centered, team-based model of care developed in the USA to coordinate diagnosis, treatment and follow-up; however, due to different healthcare systems, scientific findings in the USA cannot be simply transferred to Germany. OBJECTIVE: This preliminary study was carried out to evaluate the effects of a new interdisciplinary treatment bundle (patient-centered perioperative vigilance, PPV) in a German university hospital. MATERIAL AND METHODS: After IRB approval and written informed consent, 34 patients (PPV group) undergoing elective endoprosthetic surgery were enrolled after introduction of the PPV bundle (1. preoperative patient education, 2. specific surgical technique, 3. specific anesthesia technique, 4. start of mobilization on day of operation) and compared to historic matched pairs (HMP) for age cohort, ASA-PS, body mass index, and sex. We hypothesized that PPV shortens induction time (primary outcome). Secondary outcomes were length of hospital stay (LOS), resting pain and pain with movement on postoperative day 1 and mobilization progress on postoperative days 1, 3 and 6. Groups were compared with Wilcoxon-Mann-Whitney test for noninferiority. In the case of noninferiority, a Wilcoxon-Whitney-Mann test for superiority was additionally applied. RESULTS: The median anesthesia induction time was 13.5 min for PPV and 60 min for HMP (p < 0.0001). The LOS was 8 days for PPV and 12 days for HMP (p < 0.0001). Resting pain on postoperative day 1 was 20 for PPV (30 for HMP). Pain with movement was identical (median 40). Mobilization progress was better for PPV on days 1, 3 and 6 (p < 0.0001 for each day). CONCLUSION: The concept of patient-centered perioperative vigilance (PPV) shortens induction time and hospital length of stay. Mobilization improves with PPV on day 1. Higher pain scores in PPV seem to be clinically insignificant, which warrants further study.

[Meta-analyses on measurement precision of non-invasive hemodynamic monitoring technologies in adults]. / Metaanalysen zur Messgenauigkeit nichtinvasiver hämodynamischer Überwachungstechnologien bei Erwachsenen.

An ideal non-invasive monitoring system should provide accurate and reproducible measurements of clinically relevant variables that enables clinicians to guide therapy accordingly. The monitor should be rapid, easy to use, readily available at the bedside, operator-independent, cost-effective and should have a minimal risk and side effect profile for patients. An example is the introduction of pulse oximetry, which has become established for non-invasive monitoring of oxygenation worldwide. A corresponding non-invasive monitoring of hemodynamics and perfusion could optimize the anesthesiological treatment to the needs in individual cases. In recent years several non-invasive technologies to monitor hemodynamics in the perioperative setting have been introduced: suprasternal Doppler ultrasound, modified windkessel function, pulse wave transit time, radial artery tonometry, thoracic bioimpedance, endotracheal bioimpedance, bioreactance, and partial CO2 rebreathing have been tested for monitoring cardiac output or stroke volume. The photoelectric finger blood volume clamp technique and respiratory variation of the plethysmography curve have been assessed for monitoring fluid responsiveness. In this manuscript meta-analyses of non-invasive monitoring technologies were performed when non-invasive monitoring technology and reference technology were comparable. The primary evaluation criterion for all studies screened was a Bland-Altman analysis. Experimental and pediatric studies were excluded, as were all studies without a non-invasive monitoring technique or studies without evaluation of cardiac output/stroke volume or fluid responsiveness. Most studies found an acceptable bias with wide limits of agreement. Thus, most non-invasive hemodynamic monitoring technologies cannot be considered to be equivalent to the respective reference method. Studies testing the impact of non-invasive hemodynamic monitoring technologies as a trend evaluation on outcome, as well as studies evaluating alternatives to the finger for capturing the raw signals for hemodynamic assessment, and, finally, studies evaluating technologies based on a flow time measurement are current topics of clinical research.

[Simulation-based training and OR apprenticeship for medical students : A prospective, randomized, single-blind study of clinical skills]. / Simulationsbasiertes Training und Lehre im OP für Studierende : Eine prospektive randomisierte, einfach verblindete Studie klinischer Fertigkeiten.

BACKGROUND: Simulation-based training (SBT) has developed into an established method of medical training. Studies focusing on the education of medical students have used simulation as an evaluation tool for defined skills. A small number of studies provide evidence that SBT improves medical students' skills in the clinical setting. Moreover, they were strictly limited to a few areas, such as the diagnosis of heart murmurs or the correct application of cricoid pressure. Other studies could not prove adequate transferability from the skills gained in SBT to the patient site. Whether SBT has an effect on medical students' skills in anesthesiology in the clinical setting is controversial. To explore this issue, we designed a prospective, randomized, single-blind trial that was integrated into the undergraduate anesthesiology curriculum of our department during the second year of the clinical phase of medical school. OBJECTIVES: This study intended to explore the effect of SBT on medical students within the mandatory undergraduate anesthesiology curriculum of our department in the operating room with respect to basic skills in anesthesiology. MATERIALS AND METHODS: After obtaining ethical approval, the participating students of the third clinical semester were randomized into two groups: the SIM-OR group was trained by a 225 min long SBT in basic skills in anesthesiology before attending the operating room (OR) apprenticeship. The OR-SIM group was trained after the operating room apprenticeship by SBT. During SBT the students were trained in five clinical skills detailed below. Further, two clinical scenarios were simulated using a full-scale simulator. The students had to prepare the patient and perform induction of anesthesia, including bag-mask ventilation after induction in scenario 1 and rapid sequence induction in scenario 2. Using the five-point Likert scale, five defined skills were evaluated at defined time points during the study period. 1) application of the safety checklist, 2) application of basic patient monitoring, 3) establishment of intravenous access, 4) bag-and-mask ventilation, and 5) adjustment of ventilatory parameters after the patients' airways were secured. A cumulative score of 5 points was defined as the best and a cumulative score of 25 as the worst rating for a defined time point. The primary endpoint was the cumulative score after day 1 in the operating room apprenticeship and the difference in cumulative scores from days 1 to 4. Our hypothesis was that the SIM-OR group would achieve a better score after day 1 in the operating room apprenticeship and would gain a larger increase in score from day 1 to day 4 than the OR-SIM group. RESULTS: 73 students were allocated to the OR-SIM group and 70 students to the SIM-OR group. There was no significant difference between the two groups after day 1 of the operating room apprenticeship and no difference in increase of the cumulative score from day 1 to day 4 (median of cumulative score on day 1: 'SIM-OR' 11.2 points vs. 'OR-SIM' 14.6 points; p = 0.067; median of difference from day 1 to day 4: 'SIM-OR' -3.7 vs. 'OR-SIM' -6.4; p = 0.110). CONCLUSION: With the methods applied, this study could not prove that 225 min of SBT before the operating room apprenticeship increased the medical students' clinical skills as evaluated in the operating room. Secondary endpoints indicate that medical students have better clinical skills at the end of the entire curriculum when they have been trained through SBT before the operating room apprenticeship. However, the authors believe that simulator training has a positive impact on students' acquisition of procedural and patient safety skills, even if the methods applied in this study may not mirror this aspect sufficiently.

Cerebral oxygen saturation and cardiac output during anaesthesia in sitting position for neurosurgical procedures: a prospective observational study.

BACKGROUND: Neurosurgical operations in the dorsal cranium often require the patient to be positioned in a sitting position. This can be associated with decreased cardiac output and cerebral hypoperfusion, and possibly, inadequate cerebral oxygenation. In the present study, cerebral oxygen saturation was measured during neurosurgery in the sitting position and correlated with cardiac output. METHODS: Perioperative cerebral oxygen saturation was measured continuously with two different monitors, INVOS® and FORE-SIGHT®. Cardiac output was measured at eight predefined time points using transoesophageal echocardiography. RESULTS: Forty patients were enrolled, but only 35 (20 female) were eventually operated on in the sitting position. At the first time point, the regional cerebral oxygen saturation measured with INVOS® was 70 (sd 9)%; thereafter, it increased by 0.0187% min-1 (P<0.01). The cerebral tissue oxygen saturation measured with FORE-SIGHT® started at 68 (sd 13)% and increased by 0.0142% min-1 (P<0.01). The mean arterial blood pressure did not change. Cardiac output was between 6.3 (sd 1.3) and 7.2 (1.8) litre min-1 at the predefined time points. Cardiac output, but not mean arterial blood pressure, showed a positive and significant correlation with cerebral oxygen saturation. CONCLUSIONS: During neurosurgery in the sitting position, the cerebral oxygen saturation slowly increases and, therefore, this position seems to be safe with regard to cerebral oxygen saturation. Cerebral oxygen saturation is stable because of constant CO and MAP, while the influence of CO on cerebral oxygen saturation seems to be more relevant. CLINICAL TRIAL REGISTRATION: NCT01275898.

Time course of cerebrovascular autoregulation during extreme Trendelenburg position for robotic-assisted prostatic surgery.

Trendelenburg positioning in combination with pneumoperitoneum during robotic-assisted prostatic surgery possibly impairs cerebrovascular autoregulation. If cerebrovascular autoregulation is disturbed, arterial hypertension might induce cerebral hyperaemia and brain oedema, while low arterial blood pressure can induce cerebral ischaemia. The time course of cerebrovascular autoregulation was investigated during use of the Trendelenburg position and a pneumoperitoneum for robotic-assisted prostatic surgery using transcranial Doppler ultrasound. Cerebral blood flow velocity was correlated with arterial blood pressure and the autoregulation index (Mx) was calculated. In 23 male patients, Mx was assessed at baseline, after induction of general anaesthesia, during the Trendelenburg position (40-45°), and after repositioning. During the Trendelenburg position, Mx increased over time, indicating an impairment of cerebrovascular autoregulation. After repositioning, Mx recovered to baseline levels. It can be concluded that with longer durations of Trendelenburg position and pneumoperitoneum, cerebrovascular autoregulation deteriorates, and, therefore, blood pressure management should be adapted to avoid cerebral oedema and the duration of Trendelenburg position should be as short as possible.

[Aspects of perioperative care in patients with diabetes]. / Aspekte der perioperativen Behandlung von Diabetespatienten.

Diabetes is a common disease in Germany. Due to diabetes-associated end-organ disease, such as large and small vessel disease and neuropathy, diabetic patients require more intense anesthesia care during the perioperative phase. An in-depth and comprehensive medical history focusing on hemodynamic alterations, gastroparesis, neuropathy and stiff joint syndrome is a cornerstone of perioperative care and may affect outcome of diabetes patients more than specific anesthetic medications or the anesthetic procedure. Intraoperative anesthetic care needs to focus on preservation of hemodynamic stability, perioperative infection control and maintenance of glucose homeostasis. Whereas some years ago strict glucose control by aggressive insulin therapy was adamantly advocated, the results of recent studies have put the risk of such therapeutic algorithms into perspective. Therefore, optimized perioperative care of diabetic patients consists of setting a predefined targeted blood glucose level, evidence-based therapeutic approaches to reach that goal and finally adequate and continuous monitoring and amendment of the therapeutic approach if required.

[Influence of anesthesia procedure on malignant tumor outcome]. / Beeinflussung maligner Tumoren durch Anästhesieverfahren.

Malignant tumors are the second major cause of death in Germany. The essential therapy of operable cancer is surgical removal of primary tumors combined with adjuvant therapy. However, several consequences of surgery may promote metastasis, such as shedding of tumor cells into the circulation, decrease in tumor-induced antiangiogenesis factors, excessive release of growth factors for wound healing and suppression of immunity induced by surgical stress. In the last decade it has become clear that cell-mediated immunity controls the development of metastasis. Various perioperative factors, such as surgical stress, certain anesthetic and analgesic drugs and pain can suppress the patients' immune system perioperatively. On the other hand, by modifications of the anesthesia technique (e.g. regional anesthesia) and perioperative management to minimize immunosuppression, anesthesiologists can play a considerable role for a better outcome in patients having malignant tumors. Sufficient clinical evidence is not yet available to prove or disprove the hypothesis that anesthesia practice can improve cancer prognosis. Despite difficulties in study design, several prospective randomized trials are currently running and the results are awaited to elucidate this topic.

Evaluation of stroke volume variation obtained by arterial pulse contour analysis to predict fluid responsiveness intraoperatively.

BACKGROUND: Fluid management guided by oesophageal Doppler monitor has been reported to improve perioperative outcome. Stroke volume variation (SVV) is considered a reliable clinical predictor of fluid responsiveness. Consequently, the aim of the present trial was to evaluate the accuracy of SVV determined by arterial pulse contour (APCO) analysis, using the FloTrac/Vigileo system, to predict fluid responsiveness as measured by the oesophageal Doppler. METHODS: Patients undergoing major abdominal surgery received intraoperative fluid management guided by oesophageal Doppler monitoring. Fluid boluses of 250 ml each were administered in case of a decrease in corrected flow time (FTc) to <350 ms. Patients were connected to a monitoring device, obtaining SVV by APCO. Haemodynamic variables were recorded before and after fluid bolus application. Fluid responsiveness was defined as an increase in stroke volume index >10%. The ability of SVV to predict fluid responsiveness was assessed by calculation of the area under the receiver operating characteristic (ROC) curve. RESULTS: Twenty patients received 67 fluid boluses. Fifty-two of the 67 fluid boluses administered resulted in fluid responsiveness. SVV achieved an area under the ROC curve of 0.512 [confidence interval (CI) 0.32-0.70]. A cut-off point for fluid responsiveness was found for SVV > or =8.5% (sensitivity: 77%; specificity: 43%; positive predictive value: 84%; and negative predictive value: 33%). CONCLUSIONS: This prospective, interventional observer-blinded study demonstrates that SVV obtained by APCO, using the FloTrac/Vigileo system, is not a reliable predictor of fluid responsiveness in the setting of major abdominal surgery.

Effect of supplemental oxygen versus dobutamine administration on liver oxygen tension in dPP-guided normovolemic pigs.

BACKGROUND: Difference in pulse pressure (dPP) confirms adequate intravascular filling as a prerequisite for tissue perfusion. We hypothesized that both oxygen and dobutamine increase liver tissue oxygen tension (ptO(2)). METHODS: Eight anesthetized pigs received dPP-guided fluid management. Hepatic pO(2) was measured with Clark-type electrodes placed subcapsularly, and on the liver surface. Pigs received: (1) supplemental oxygen (F(i)O(2) 1.0); (2) dobutamine 2.5 microg/kg/min, and (3) dobutamine 5 microg/kg/min. Data were analyzed using repeated-measures ANOVA followed by a Tukey post-test for multiple comparisons. ptO(2 )measured subcapsularly and at the liver surface were compared using the Bland-Altman plot. RESULTS: Variation in F(i)O(2) changed local hepatic tissue ptO(2) [subcapsular measurement: 39 +/- 12 (F(i)O(2) 0.3), 89 +/- 35 mm Hg (F(i)O(2) 1.0, p = 0.01 vs. F(i)O(2) 0.3), 44 +/- 10 mm Hg (F(i)O(2) 0.3, p = 0.05 vs. F(i)O(2) 1.0); surface measurement: 52 +/- 35 (F(i)O(2) 0.3), 112 +/- 24 mm Hg (F(i)O(2) 1.0, p = 0.001 vs. F(i)O(2) 0.3), 54 +/- 24 mm Hg (F(i)O(2) 0.3, p = 0.001 vs. F(i)O(2) 1.0)]. Surface measurements were widely scattered compared to subcapsular measurements (bias: -15 mm Hg, precision: 76.3 mm Hg). Dobutamine did not affect hepatic oxygenation. CONCLUSION: Supplemental oxygen increased hepatic tissue pO(2) while dobutamine did not. Although less invasive, the use of surface measurements is discouraged.

[Arterial pressure curve and fluid status]. / Arterielle Pulskurve und Volumenstatus.

Fluid optimization is a major contributor to improved outcome in patients. Unfortunately, anesthesiologists are often in doubt whether an additional fluid bolus will improve the hemodynamics of the patient or not as excess fluid may even jeopardize the condition. This article discusses physiological concepts of liberal versus restrictive fluid management followed by a discussion on the respective capabilities of various monitors to predict fluid responsiveness. The parameter difference in pulse pressure (dPP), derived from heart-lung interaction in mechanically ventilated patients is discussed in detail. The dPP cutoff value of 13% to predict fluid responsiveness is presented together with several assessment techniques of dPP. Finally, confounding variables on dPP measurements, such as ventilation parameters, pneumoperitoneum and use of norepinephrine are also mentioned.

Perioperative fluid management: comparison of high, medium and low fluid volume on tissue oxygen pressure in the small bowel and colon.

BACKGROUND AND OBJECTIVE: Insufficient blood flow and oxygenation in the intestinal tract is associated with increased incidence of postoperative complications after bowel surgery. High fluid volume administration may prevent occult regional hypoperfusion and intestinal tissue hypoxia. We tested the hypothesis that high intraoperative fluid volume administration increases intestinal wall tissue oxygen pressure during laparotomy. METHODS: In all, 27 pigs were anaesthetized, ventilated and randomly assigned to one of the three treatment groups (n = 9 in each) receiving low (3 mL kg-1 h-1), medium (7 mL kg-1 h-1) or high (20 mL kg-1 h-1) fluid volume treatment with lactated Ringer's solution. All animals received 30% and 100% inspired oxygen in random order. Cardiac index was measured with thermodilution and tissue oxygen pressure with a micro-oximetry system in the jejunum and colon wall and subcutaneous tissue. RESULTS: Groups receiving low and medium fluid volume treatment had similar systemic haemodynamics. The high fluid volume group had significantly higher mean arterial pressure, cardiac index and subcutaneous tissue oxygenation. Tissue oxygen pressures in the jejunum and colon were comparable in all three groups. CONCLUSIONS: The three different fluid volume regimens tested did not affect tissue oxygen pressure in the jejunum and colon, suggesting efficient autoregulation of intestinal blood flow in healthy subjects undergoing uncomplicated abdominal surgery.

[Frequency distribution of dibucaine numbers in 24,830 patients]. / Verteilungsmuster der Dibucainzahl bei 24.830 Patientinnen und Patienten.

PURPOSE: Atypical cholinesterase prolongs the duration of neuromuscular blocking drugs such as succinylcholine and mivacurium. Measuring the dibucaine number identifies patients who are at risk. This study shows the frequency distribution of dibucaine numbers routinely measured and discusses avoidable clinical problems and economic implications. METHODS: Dibucaine numbers were measured on a Hitachi 917-analyzer and all dibucaine numbers recorded over a period of 4 years were taken into consideration. Repeat observations were excluded. RESULTS: A total of 24,830 dibucaine numbers were analysed and numbers below 30 were found in 0.07% ( n=18) giving an incidence of 1:1,400. Dibucaine numbers from 30 to 70 were found in 1.23% ( n=306). On the basis of identification of the Dibucaine numbers we could avoid the administration of succinylcholine or mivacurium resulting in a cost reduction of 12,280 Euro offset against the total laboratory costs amounting to 10,470 Euro. CONCLUSIONS: An incidence of 1:1,400 of dibucaine numbers below 30 is higher than documented in the literature. Therefore, routine measurement of dibucaine number is a cost-effective method of identifying patients at increased risk of prolonged neuromuscular blockade due to atypical cholinesterase.

[Rocuronium or vecuronium for intubation for short operations in the preschool age? Effects on time in the operating room and postoperative phase]. / Rocuronium oder vecuronium zur Intubation bei kurzen Eingriffen im Vorschulalter? Auswirkungen auf den Zeitablauf im Operationssaal und die postoperative Phase.

This prospective randomized study compares the effects of rocuronium (R) and vecuronium (V) on the early postoperative period in infants. Forty-eight infants between the ages of three and six, scheduled for elective ENT procedures, were studied after prior approval of local ethics committee and informed parental consent. All children were premedicated with chlorprotixene and belladonna. Anaesthesia was induced with 5 mg/kg thiopentone and 1 vol.-% halothane. Subsequently, 0.4 mg/kg rocuronium or 0.075 mg/kg vecuronium were administered, respectively. Anaesthesia and post-operative care were conducted by independent anaesthetists, who were unaware of the drug used and of the relaxometric data obtained. All children were monitored in the recovery room by pulse oximetry until they reached a Steward Score of 6. Demographic data did not differ between the groups. No differences were recorded between the non-depolarizing relaxants regarding intubation time (R: 24.1 +/- 4.2 min, V: 25.8 +/- 6.8 min) and the time interval from end extubation to leaving the operating theatre (R: 2.3 +/- 0.8 min, V: 2.6 +/- 1.2 min), respectively. Similarly, no differences in SaO2 were noted during the recovery period in the recovery room. Significant differences between the non-depolarizing relaxants were found in the TOF-ratios at extubation (R: 0.73 +/- 0.31 min, V: 0.48 +/- 0.34 min) and arrival in the recovery room (R: 0.88 +/- 0.21 min, V: 0.69 +/- 0.26 min). 0.4 mg/kg Rocuronium and 0.075 mg/kg vecuronium can be used for intubation during short operations on pre-school children. Rocuronium may be the better alternative, due to its faster neuromuscular recovery properties.

[Gastric mucosa tonometry in routine monitoring in the surgical intensive care unit]. / Magenmukosa-Tonometrie im Routinemonitoring auf der operativen Intensivstation.

PURPOSE: Monitoring tissue oxygenation in the splanchnic region could be helpful for critically ill patients. In this study the postoperative course of gastric mucosal CO2 (prCO2) in 40 patients is shown. METHODS: Following approval of the ethics committee, 24 patients schedulded for surgery with an expected large fluid turnover and 16 multiple injured patients were monitored with a gas tonometry device in addition to standard monitoring (ECG, pulse oximetry, capnometry, CVP, arterial pressure). Normoventilated patients with prCO2 > 50 for more than 30 minutes were treated with fluid therapy, followed by catecholamine therapy, followed by transfusion (fig. 1). All patients were admitted to the SICU post-operatively. RESULTS AND DISCUSSION: The variation of prCO2-values was greater in multiple injured patients. Their prCO2-values began in a lower range compared to patients with scheduled operation, became higher at the end of the first SICU-day and remained higher thereafter. They had a higher fluid turnover and needed more catecholamines. Multiple injured patients with an arterio-intestinal CO2-Difference (CO2-Gap) > 10 had a higher ISS-Score, were longer mechanically ventilated, had a longer SICU-stay and a higher incidence of complications in comparison to patients with aCO2-Gap < 10. Perhaps a CO2-Gap > 10 could be predictive for a more severe course in intensive care patients.

[A comparison of the effect of propofol in 3 subhypnotic doses within the framework of tumor chemotherapy]. / Wirkungsvergleich von Propofol in drei subhypnotischen Dosierungen im Rahmen der Tumor-Chemotherapie.

PURPOSE: In anaesthesia and critical care propofol is often used as a hypnotic or sedative. There are some reports showing propofol as a mood-altering drug. The use of propofol in subanaesthetic doses, for example in antineoplastic chemotherapy, led to similar results. In previous studies it was hypothesised that these mood effects could also reduce chemotherapy-induced nausea and vomiting. The present prospective randomised double-blind study evaluated mood effects of different subanaesthetic doses of propofol in oncology patients who received antineoplastic chemotherapy. METHODS: Propofol was applied in a double-blind and randomised manner as follows (N = 8 per group): Initial bolus of 0.1 mg/kg followed by a continuous infusion of 1.0 mg/kgxh (group 1), 1.5 mg/kgxh (group 2) or 2.0 mg/kgxh (group 3). Dependent variables were as behavioural (i.e. nausea and vomiting) as aspects of mood as somatic aspects. RESULTS: Subanaesthetic doses of propofol showed different effects. In respect of somatic variables some well-known results were replicated, showing highest reduction of blood pressure under highest dose of propofol. With regard to psychic variables no deterioration of mood or feeling tone was seen. Rather, a reduction of anxiety and especially under 2.0 mg/kgxh an induction of well-being occurred. However, even propofol was used as the only "anti-emetic" drug, patients reported no induction of nausea and vomiting during antineoplastic chemotherapy. CONCLUSIONS: Further studies are needed to specify the "anti-emetic" effects of subhypnotic propofol in antineoplastic chemotherapy. Especially a comparison with a standard drug for the prevention of nausea and vomiting, such as ondansetron, will have to be conducted. The results of this study showed that a dose of propofol of 1.0 mg/kgxh after an initial bolus of 0.1 mg/kg is a useful reference dose.

Mood effects of zolpidem versus phenobarbital combined with promethazine in an anesthesiological setting.

Zolpidem, a new imidazo-pyridine hypnotic, acts like a benzodiazepine. Because of its short half-life, zolpidem plays a special role in the group of drugs suitable for anesthesiological premedication because of its sedative and anxiolytic effects. The study compared preanesthesiological treatment by zolpidem and phenobarbital in combination with promethazine in a clinical setting. In a double-blind randomized design, 304 patients awaiting different kinds of surgery were studied. For the assessment of emotional states, a multidimensional rating scale was administered. The study showed differing effects of zolpidem and phenobarbital, which could be demonstrated in the scales 'irritation', 'vulnerability', and 'aggression' and could therefore represent in domain hostility. In most of the other scales there were similar effects of phenobarbital and zolpidem. Assuming that phenobarbital is a potent sedative, the reported results confirm the results found by other authors, that zolpidem also acts as a sedative. The reported results describe promethazine as selectively deactivating. These results are in agreement with the findings of an experimental study which tested the acute effects of stress under promethazine.