PubMed Health⌕ Search

Biomedical subjects

Thomas Standl

Publications and source records attributed to Thomas Standl.

At least 19 recordsLinked to original sources
PubMed2006

Cost drivers in anesthesia: manpower, technique and other factors.

PURPOSE OF REVIEW: This article reviews the recent literature on cost drivers in anesthesia with respect to staff, techniques and drug costs, and with special focus on anesthesia workflow in the postanesthesia care unit. Moreover, the costs of post-operative pain management provided by an acute pain service are highlighted. RECENT FINDINGS: Staff costs represent the main contributor to anesthesia costs in all studies. Therefore, many studies address the reduction of personnel costs, e.g. by using fast-tracking procedures which allow the patients to bypass the postanesthesia care unit. However, postanesthesia care unit bypassing and replacement of anesthesiologists by certified anesthesia nurses were not able to significantly decrease anesthesia costs. If anesthesiologists are reimbursed by surgically controlled time, this time is the main determinator for anesthesia costs and should be carefully monitored. Regional anesthesia techniques can help to reduce costs in the ambulatory setting because of reduced post-operative side-effects and earlier home readiness of the patients. Low gas flow and modern electroencephalographic monitoring can contribute to decreased drug-related costs. Acute pain services are mainly run by anesthesia staff thus increasing the costs in anesthesia departments. However, an acute pain service can reduce costs of surgical procedures significantly. SUMMARY: Clear definition of the meaning of cost drivers and of criteria which allow assessment of patients' condition, and peri-operative standard operating procedures are warranted to ensure comparability of economic data in anesthesia.

Anesthesia↗
PubMed2005

Influence of the hemoglobin solution HBOC-201 on tissue oxygenation in the rat R1H-tumor.

BACKGROUND: HBOC-201 is an ultra purified bovine hemoglobin solution. It has already been used in clinical phase II/III trials for emergency treatments. Animal experiments have shown that HBOC-201 is highly effective in tissue oxygenation. The study was performed in order to assess the potential of low dose HBOC-201 to improve tumor oxygenation. METHODS: 30 rats with a subcutaneously growing rhabdomyosarcoma R1H tumor were randomly assigned either to be ventilated with carbogen (n = 10), or to receive an IV injection of 0.3 g/kg HBOC-201 (n = 10) or a combination of 0.3 g/kg HBOC-201 and carbogen breathing (n = 10). Under general anesthesia the effects of the respective treatment on the tissue oxygen tension (tpO2) of the tumor were determined using a flexible stationary probe at baseline (b) and 15 and 60 min after application of the respective medication. RESULTS: HBOC-201 alone failed to improve tumor tpO2 (b: 1.3 +/- 1.2mmHg; 15min: 1.4 +/- 1 mmHg; 60min: 1 +/- 1 mmHg). In combination with carbogen the mean tpO2 of the tumor raised in comparison to baseline values (b: 3.1 +/- 4.6 mmHg; mmHg; 15min: 8.5 +/- 11*mmHg; 60min: 4.8 +/- 5mmHg; *p < 0.05 vs. b), but this effect was less pronounced than the increase in tpO2 by carbogen alone (b: 3.4 +/- 3.4mmHg; 15min: 9 +/- 10* mmHg; 60 min: 13 +/- 19* mmHg; *p < 0.05 vs. b). CONCLUSION: The application of low dose hemoglobin solution HBOC-201 does not result in improvement of tissue oxygenation in the rat rhabdomyosarcoma R1H.

Animals↗
PubMed2005

Microcirculatory function and tissue damage is improved after therapeutic injection of bovine hemoglobin in severe acute rodent pancreatitis.

OBJECTIVES: Stasis of the pancreatic microcirculation initiates and aggravates acute pancreatitis. Bovine hemoglobin has been shown to improve microcirculation in acute pancreatitis if prophylactically infused 15 minutes after initiation of acute pancreatitis. The purpose of this study was to evaluate the therapeutic effectiveness of bovine hemoglobin on pancreatic microcirculation and tissue damage later in the course of experimental acute rodent pancreatitis. METHODS: In Wistar rats, severe acute pancreatitis was induced by administration of glyco-deoxycholic-acid intraductally and cerulein intravenously. Pancreatic microcirculation was continuously monitored by intravital microscopy. Three hours after the initiation of acute pancreatitis, animals received either 0.8 mL bovine hemoglobin (Oxyglobin), hydroxyethyl starch (HES), or 2.4 mL 0.9% NaCl intravenously at random. After 6 hours, animals were killed, and histopathological damage of the pancreas was assessed using a validated histology score. RESULTS: Pancreatic microcirculation assessed by leukocyte adherence was significantly improved by the administration of bovine hemoglobin in comparison with normal saline over time (mean difference, 51.6 +/- 9.2; P < 0.001) and HES (mean difference, 24.1 +/- 9.2; P = 0.037). This result was paralleled by decreased tissue damage in the bovine hemoglobin group as opposed to NaCl (6.75 vs. 12; range, 5.25-7.75 vs. 8.25-14; P < 0.001) and HES (6.75 vs. 9; range, 5.25-7.75 vs. 7.5-10.75; P < 0.001). CONCLUSION: Therapeutic intravenous infusion of bovine hemoglobin improves pancreatic microcirculation and reduces pancreatic tissue damage in severe acute rodent pancreatitis but is not as effective as early (prophylactic) administration.

Acute Disease↗
PubMed2005

A retrospective comparison of costs for regional and general anesthesia techniques.

In this retrospective study, we compared the costs for three different regional anesthesia techniques with the costs of general anesthesia (GA). A total of 1587 anesthesia cases which were performed for orthopedic and trauma patients over a 1-yr period in a tertiary level, university hospital setting were analyzed. The anesthesia technique-related costs were determined calculating case-specific costs for personnel, supplies, and drugs. The techniques were compared on the basis of anesthesia costs and surgical procedure duration. As a result, we found that the costs per surgical minute largely depend on the surgical procedure duration. Based on the regression function, the cost advantage of spinal anesthesia over GA can be estimated to be 13% for a 50-min case, 9% for a 100-min case, and 5% for a 200-min case. The cost disadvantage of brachial plexus anesthesia over GA can be estimated to be 19% for a 50-min case, 8% in a 100-min case, and 1% for a 200-min case. We found no difference in costs between epidural and GA. We concluded that cost comparisons of anesthesia techniques largely depend on the surgical duration of the cases studied. Even in a teaching hospital setting, spinal anesthesia has economic advantages over GA. Especially for short cases, brachial plexus block is more expensive in this setting.

Adult↗
PubMed2005

Reduction of anesthesia process times after the introduction of an internal transfer pricing system for anesthesia services.

To improve operating room workflow, an internal transfer pricing system (ITPS) for anesthesia services was introduced in our hospital in 2001. The basic principle of the ITPS is that the department of anesthesia receives reimbursement only for the surgically controlled time, not for anesthesia-controlled time (ACT). A reduction in anesthesia process times is therefore beneficial for the anesthesia department. In this study, we analyzed the ACT (with its parts: preparation before induction, induction, extubation, and recovery room transfer) for 3 yr before and 3 yr after the introduction of the ITPS in 55,776 cases. Furthermore, the anesthesia cases were subsegmented into 10 different anesthesia techniques, and the process times were studied. The average total ACT was reduced from 40.4 +/- 23.5 min in 1998 to 34.3 +/- 21.7 min in 2003. The main effect came from reductions in anesthesia preparation time and recovery room transfer time, whereas induction and extubation time changed little. A significant reduction in average ACT was seen in 7 of 10 analyzed anesthesia techniques, ranging from 4 to 18 min. We conclude that transfer pricing of anesthesia services based on the surgically controlled time can be a successful approach to reduce anesthesia process times.

Anesthesia↗
PubMed2005

A new oxygen transport agent.

Modern highly purified and chemically modified hemoglobin-based oxygen carriers (HBOC) are free of significant side effects on kidneys and coagulation, and they do not possess ABO antigens, allowing transfusion without knowledge of the respective blood group. Even at room air oxygen concentrations HBOC can compensate for intravascular volume deficits in hemorrhagic shock, including restoration of colloid osmotic pressure and organ perfusion, and deliver oxygen to organs and tissues during nearly complete blood exchange. In animal experiments and clinical trials all HBOC showed a vasoconstrictive side-effect which is mainly caused by nitric oxide scavenging, and to a lesser extent by reactive vasoconstriction because of precapillary oxygen off-loading. The study by Bjorkholm in this issue of the journal (see page 505) investigates the application of a moderate dose of the newly designed HBOC, MP4, in volunteers. MP4 has a high molecular size and a very low p50 resulting in a high oxygen affinity thus avoiding significant (pre)capillary oxygen off-loading. No significant rises in blood pressure or major laboratory abnormalities were seen after MP4 infusion. This new HBOC may be applicable in patients as a red blood substitute where vasoconstriction must be avoided. In addition, poststenotic tissue oxygenation might be a further indication. However, the number of treated volunteers and the infused dose of MP4 were both are very small. Therefore, one cannot draw conclusions on the safety, tolerability and efficacy of MP4 in terms of red cell replacement when large amounts of oxygen carriers are needed.

Animals↗
PubMed2004

Quality of postoperative pain using an intraoperatively placed epidural catheter after major lumbar spinal surgery.

BACKGROUND: Major spinal surgery is associated with high postoperative pain scores and opioid requirement. The aim of the current prospective, randomized, placebo-controlled, double-blind study was to assess the reduction of opioid requirement and pain scores using an intraoperatively placed epidural catheter with infusion of 0.1% ropivacaine during the postoperative period. METHODS: Thirty patients undergoing major lumbar spinal surgery from a dorsal approach were included in this study. Before wound closure, the orthopedic surgeon inserted an epidural catheter. Postoperatively, patients were randomly assigned to receive an infusion of 12 ml/h ropivacaine, 0.1% (group R), or 12 ml/h saline (group N) after an initial bolus of 10 ml of the respective study solution. Additional pain relief was provided using an intravenous patient-controlled analgesia pump with the opioid piritramide. Patients were assessed with respect to pain scores (visual analog scale of 0-100), cumulative opioid requirement, side effects, and satisfaction with pain management. RESULTS: : Demographic data, duration of surgery, and type of surgery were comparable between groups. Pain scores were assessed as follows (group R vs. group N: 6 h: 24 +/-20 vs. 51 +/- 20, P = 0.002; 24 h: 33 +/- 19 vs. 53 +/- 27, P = 0.04; 48 h: 21 +/-17 vs. 40 +/- 26, P = 0.04; 72 h: 14 +/- 13 vs. 38 +/- 25, P = 0.02). The cumulative piritramide requirement after 72 h was 97 +/- 23 mg in group R and 157 +/-72 mg in group N (P = 0.03). The incidence of side effects was comparable between groups, and patient satisfaction was always higher in group R (P < 0.05). CONCLUSION: Continuous epidural infusion of 0.1% ropivacaine results in lower pain scores and opioid consumption and higher patient satisfaction when compared with placebo. Application of ropivacaine using an epidural catheter seems to be a highly effective treatment for postoperative pain after major lumbar spinal surgery.

Adult↗
PubMed2004

Comparative evaluation of the Datex-Ohmeda S/5 Entropy Module and the Bispectral Index monitor during propofol-remifentanil anesthesia.

BACKGROUND: Different analytical concepts were introduced to quantify the changes of the electroencephalogram. The Datex-Ohmeda S/5 Entropy Module (Datex-Ohmeda Division, Instrumentarium Corp., Helsinki, Finland) was the first commercial monitor based on the entropy generating two indices, the state entropy (SE) and the response entropy (RE). The aim of the current study was to compare the accuracy of SE and RE with the Bispectral Index(R) monitor (BIS(R); Aspect Medical Systems, Newton, MA) during propofol-remifentanil anesthesia. METHODS: The authors investigated 20 female patients during minor gynecologic surgery. SE, RE, BIS, mean arterial blood pressure, heart rate, and sedation level were recorded every 20 s during stepwise increase (target-controlled infusion, 0.5 microg/ml) of propofol until the patients lost response. Five minutes after loss of response, remifentanil infusion (0.4 microg . kg(-1) . min(-1)) was started. Spearman correlation coefficient and prediction probability were calculated for sedation levels with SE, RE, BIS, mean arterial blood pressure, and heart rate. The ability of the investigated parameters to distinguish between the anesthesia steps awake versus loss of response, awake versus anesthesia, anesthesia versus first reaction, and anesthesia versus extubation was analyzed with the prediction probability. RESULTS: SE correlates best with sedation levels, but no significant differences of the prediction probability values among SE, RE, and BIS were found. The prediction probability for all investigated steps of anesthesia did not show significant differences among SE, RE, and BIS. SE, RE, and BIS were superior to mean arterial blood pressure and heart rate. CONCLUSION: SE, RE, and BIS revealed similar information about the level of sedation and allowed the authors to distinguish between different steps of anesthesia. Both monitors provided useful additional information for the anesthesiologist.

Acoustic Stimulation↗
PubMed2004

Effect of different cost drivers on cost per anesthesia minute in different anesthesia subspecialties.

BACKGROUND: Little is known about differences in costs to provide anesthesia care for different surgical subspecialties and which factors influence the subspecialty-specific costs. METHODS: In this retrospective study, the authors determined main cost components (preoperative visit, intraoperative personnel costs, material and pharmaceutical costs, and others) for 10,843 consecutive anesthesia cases from a 6-month period in the 10 largest anesthesia subspecialties in their university hospital: ophthalmology; general surgery; obstetrics and gynecology; ear, nose, and throat surgery; oral and facial surgery; neurosurgery; orthopedics; cardiovascular surgery; traumatology; and urology. Using regression analysis, the effect of five presumed cost drivers (anesthesia duration, emergency status, American Society of Anesthesiologists physical status of III or higher, patient age younger 6 yr, and placement of invasive monitoring) on subspecialty-specific costs per anesthesia minute were analyzed. RESULTS: Both personnel costs for anesthesiologists and total costs calculated per anesthesia minute were inversely correlated with the duration of anesthesia (adjusted R2 = 0.75 and 0.69, respectively), i.e., they were higher for subspecialties with short cases and lower for subspecialties with longer cases. The multiple regression model showed that differences in anesthesia duration alone accounted for the majority of the cost differences, whereas the other presumed cost drivers added only little to explain subspecialty-specific cost differences. CONCLUSIONS: Different anesthesia subspecialties show significant and financially important differences regarding their specific costs. Personnel costs and total costs are highest for subspecialties with the shortest cases. Other analyzed cost drivers had little effect on subspecialty-specific costs. In the light of these cost differences, a detailed cost analysis seems necessary before the profitability of an anesthesia subspecialty can be assessed.

Adult↗
PubMed2004

Alaris AEP monitor's "Click Detection" does not help to detect inadvertent disconnection of headphones during anesthesia.

UNLABELLED: Auditory evoked potentials (AEP) can be suppressed by anesthetics dose dependently, but may fail to be registered because of the absence of adequate auditory stimuli. The Alaris AEP monitor includes the "Click Detection" (CD) (generating the message "NO AEP" or "LOW AEP") to detect the loss of auditory stimuli. We investigated the accuracy of the CD in 17 patients awake (AWAKE) and during anesthesia (ANESTHESIA) with accurately placed headphones (HP) and after disconnected HP (No HP) over 5 min each, respectively. Alaris AEP ARX index, CD, and Bispectral Index were recorded each minute. Changes were evaluated with the Friedman and Wilcoxon test. Sensitivity (SEN) and specificity (SPE) and receiver operating characteristic curve were analyzed for the accuracy of the CD. During AWAKE after disconnection of the HP, Alaris AEP ARX index decreased significantly (P < 0.05). The CD was able to detect No HP after 2 min with a SEN of 88% and a SPE of 97%. During ANESTHESIA, no changes were found after HP disconnection. CD detected No HP with a SEN of 100% and a SPE of 20%. The CD of the Alaris AEP monitor is not able to detect unnoticed disconnection of HP during ANESTHESIA. IMPLICATIONS: Signal transmission of auditory evoked potentials can be suppressed by anesthetics, but also by disconnection of headphones. In the present study, we demonstrate that even the Alaris AEP monitor with the very new feature "Click Detection" was not able to detect the loss of headphones during general anesthesia with propofol and remifentanil.

Acoustic Stimulation↗
PubMed2004

Cost drivers in patient-controlled epidural analgesia for postoperative pain management after major surgery.

UNLABELLED: In this retrospective study, we determined efficiency, treatment length, and resource use for postoperative pain management with patient-controlled epidural analgesia (PCEA) in 350 consecutive patients undergoing major abdominal, thoracic, gynecological, or orthopedic surgery. Average pain scores on a visual analog scale were 16 +/- 23 and 9 +/- 16 (visual analog scale range, 0 to 100) on postoperative Days 1 and 3, respectively, and were similar among groups. The treatment length was 4.9 +/- 2.2 days in general surgical, 5.2 +/- 3.1 days in gynecological, and 4.5 +/- 2.8 days in orthopedic patients. The total volumes of the mixture of local anesthetic and opioid received epidurally were 707 +/- 507 mL, 770 +/- 576 mL, and 593 +/- 456 mL in the general surgical, gynecological, and orthopedic groups, respectively. The average total costs for all groups for the full treatment course with PCEA were 447 +/- 218 per case (1 equals approximately US dollar 1). Fifty-one percent of these costs were staff costs, 20% were costs for the applied drugs, 15% were costs for PCEA pumps and pump material, and 13% were costs for the initial catheter insertion. In the light of these costs and the availability of less costly alternatives, measurements for cost containment by using PCEA are recommended. Because treatment length is the main cost driver both for drug and staff costs, close monitoring of treatment length and a predefined migration path to alternative techniques after PCEA should be considered. IMPLICATIONS: Patient-controlled epidural analgesia is increasingly used as first-line treatment for postoperative pain management. In this study, costs and cost drivers are analyzed for the first time for this new technique, based on 350 cases of pain therapy after major surgery in a university hospital.

Adult↗
PubMed2004

Spinal anesthesia performance conditions and side effects are comparable between the newly designed Ballpen and the Sprotte needle: results of a prospective comparative randomized multicenter study.

UNLABELLED: In this study, we examined the characteristics of a newly designed spinal needle (Ballpen [B]) with a pencil-like tip formed by a stylet that is withdrawn after penetration of the dura. The main goal was to examine whether the use of the B needle could reduce performance time by improved puncture conditions in comparison with the Sprotte (S) needle. Seven-hundred patients at 4 hospitals received single-dose spinal anesthesia with a 25-gauge B or S needle and 0.5% bupivacaine. The performance time of spinal anesthesia was defined as the time between insertion of the introducer needle and the first identification of cerebrospinal fluid in the hub of the spinal needle. Failed spinals were assessed when patients required general anesthesia. On postoperative Day 2-4, all patients were visited and interviewed. Groups did not differ with respect to demographics, puncture site, and dose of bupivacaine. Performance time was 98 +/- 145 s in Group B and 103 +/- 159 s in Group S (P = 0.68). The failure rate in Groups B and S was 3.8% and 3.9%, respectively, and the incidence of postdural puncture headache was 1.8% and 0.9% (P = 0.50), respectively. We conclude that there was no difference in technical variables or outcome between the B and S needles. IMPLICATIONS: This multicenter study examined characteristics of the newly designed Ballpen needle with the Sprotte needle in 700 patients undergoing lower abdominal or extremity surgery in single-dose spinal anesthesia. Technical variables and side effects were comparable between both noncutting spinal needles.

Adolescent↗
PubMed2004

Epidural hematoma after spinal anesthesia in a patient with undiagnosed epidural lymphoma.

UNLABELLED: The incidence of hemorrhagic complications after neuroaxial anesthesia is very infrequent. We report a case of a woman developing epidural bleeding 3 wk after performing an uneventful spinal anesthesia at the lumbar level L3-4 for removal of a wire loop in her left knee. No hemostasis altering medication had been taken before and after spinal puncture. The hematoma presenting at the lumbar level L2-3 had to be removed via laminectomy. Pathological examination of the hematoma revealed a highly vascularized centroblastic non-Hodgkin's lymphoma that was not diagnosed before surgery. The patient did not develop any neurological deficits. IMPLICATIONS: We report a case of a women developing epidural bleeding 3 wk after performing an uneventful spinal anesthesia for removal of a wire loop in her left knee. Pathological examination of the neurosurgically removed hematoma revealed a highly vascularized epidural centroblastic non-Hodgkin lymphoma.

Anesthesia, Spinal↗
PubMed2004

Comparative evaluation of Narcotrend, Bispectral Index, and classical electroencephalographic variables during induction, maintenance, and emergence of a propofol/remifentanil anesthesia.

UNLABELLED: In the present study, we sought to compare the abilities of Narcotrend (NT) with the Bispectral Index (BIS) electroencephalographic system to monitor depth of consciousness immediately before induction of anesthesia until extubation during a standardized anesthetic. We investigated 26 patients undergoing laminectomy. Investigated states of anesthesia were: awake, loss of response, loss of eyelash reflex, steady-state anesthesia, first reaction, and extubation during emergence. NT, BIS, spectral edge frequency, median frequency, relative power in delta, theta, alpha, beta, and hemodynamics were recorded simultaneously. The ability of all variables to distinguish between awake versus loss of response, awake versus loss of eyelash reflex, awake versus steady-state anesthesia, steady-state anesthesia versus first reaction and extubation were analyzed with the prediction probability. Effects of remifentanil during propofol infusion were investigated with Friedman's and post hoc with Wilcoxon's test. Only NT and BIS were able to distinguish all investigated states accurately with a prediction probability >0.95. After start of remifentanil infusion, only hemodynamics changed statistically significantly (P < 0.05). NT and BIS are more reliable indicators for the assessment of anesthetic states than classical electroencephalographic variables and hemodynamics, whereas the analgesic potency of depth of anesthesia could not be detected by NT and BIS. IMPLICATIONS: The modern electroencephalographic monitoring systems Narcotrend and Bispectral Index are more reliable indicators for the assessment of anesthetic states than classical electroencephalographic and hemodynamic variables to predict anesthetic conditions from before induction of anesthesia until extubation during a standardized anesthetic regime with propofol and remifentanil. The analgesic potency of depth of anesthesia could not be detected by Narcotrend and Bispectral Index.

Adult↗
PubMed2003

Patient-controlled epidural analgesia reduces analgesic requirements compared to continuous epidural infusion after major abdominal surgery.

PURPOSE: To compare the quality of pain relief and incidence of side effects between 24-hr postoperative continuous epidural infusion (CEI) and subsequent patient-controlled epidural analgesia (PCEA) with different analgesics after major abdominal surgery. METHODS: Twenty-eight women undergoing extended gynecological tumour surgery received postoperative CEI with 0.15 mL x kg(-1) x hr(-1) 0.2% ropivacaine (R: n = 14) or 0.125% bupivacaine plus 0.5 micro g x mL(-1) sufentanil (BS: n = 14) during 24 postoperative hours. Twenty-four hours later, postoperative pain management was switched to PCEA without background infusion and 5 mL single bolus application of R or BS every 20 min at most. Visual analogue scales (VAS; 1-100 mm) were assessed by patients at rest and on coughing after 24 hr of CEI and PCEA. Side effects, doses of local anesthetics and opioids were recorded and plasma concentrations of total and unbound ropivacaine and bupivacaine were measured. RESULTS: Patients required lower doses of each respective analgesic medication with PCEA (R: 108 +/- 30 mL; BS: 110 +/- 28 mL) than with CEI (R: 234 +/- 40; BS: 260 +/- 45; P < 0.01). Ropivacaine plasma concentrations were lower 24 hr after PCEA when compared with CEI (P < 0.01). No patient after PCEA but two after CEI (n = 4; NS) presented motor block. PCEA with R provided better postoperative pain relief than CEI (37 +/- 32 vs 59+/-27, P < 0.05). No difference in parenteral opioid rescue medication between CEI and PCEA was seen. CONCLUSION: PCEA in comparison to preceding CEI provides equivalent analgesia with lower local anesthetic doses and plasma levels, and without motor blocking side effects, irrespective of the applied drug regimen.

Adult↗
PubMed2003

Narcotrend and Bispectral Index monitor are superior to classic electroencephalographic parameters for the assessment of anesthetic states during propofol-remifentanil anesthesia.

BACKGROUND: A new electroencephalogram monitor, the Narcotrend, was developed to measure anesthetic depth. The authors compared the Narcotrend, the Bispectral Index, and classic electroencephalographic and hemodynamic parameters during anesthesia with propofol and remifentanil. METHODS: The authors investigated 25 patients undergoing laminectomy at different anesthetic states: awake, steady state anesthesia, first reaction during emergence, and extubation. Narcotrend value; BIS; relative power (percent) in delta, theta, alpha, and beta; median frequency; spectral edge frequency; and hemodynamic parameters were recorded simultaneously. The ability of the classic and processed electroencephalographic and hemodynamic parameters to predict the clinically relevant anesthetic states of awake, steady state anesthesia, first reaction, and extubation was tested using prediction probability. RESULTS: Only the Narcotrend was able to differentiate between awake versus steady state anesthesia and steady state anesthesia versus first reaction/extubation with a prediction probability value of more than 0.90. CONCLUSIONS: Modern electroencephalographic parameters, especially Narcotrend, are more reliable indicators for the clinical assessment of anesthetic states than classic parameters.

Adolescent↗