Anaesthetic efficacy and postinduction hypotension with remimazolam compared with propofol: a multicentre randomised controlled trial

Remimazolam, a short-acting benzodiazepine, may be used for induction and maintenance of total intravenous anaesthesia, but its role in the management of patients with multiple comorbidities remains unclear. In this phase 3 randomised controlled trial, we compared the anaesthetic efficacy and the incidence of postinduction hypotension during total intravenous anaesthesia with remimazolam vs. propofol. A total of 365 patients (ASA physical status 3 or 4) scheduled for elective surgery were assigned randomly to receive total intravenous anaesthesia with remimazolam (n = 270) or propofol (n = 95). Primary outcome was anaesthetic effect, quantified as the percentage of time with Narcotrend® Index values ≤ 60, during surgery (skin incision to last skin suture), with a non-inferiority margin of -10%. Secondary outcome was the incidence of postinduction hypotensive events. Mean (SD) percentage of time with Narcotrend Index values ≤ 60 during surgery across all patients receiving remimazolam (93% (20.7)) was non-inferior to propofol (99% (4.2)), mean difference (97.5%CI) -6.28% (-8.89-infinite); p = 0.003. Mean (SD) number of postinduction hypotension events was 62 (38.1) and 71 (41.1) for patients allocated to the remimazolam and propofol groups, respectively; p = 0.015. Noradrenaline administration events (requirement for a bolus and/or infusion) were also lower in patients allocated to remimazolam compared with propofol (14 (13.5) vs. 20 (14.6), respectively; p < 0.001). In conclusion, in patients who were ASA physical status 3 or 4, the anaesthetic effect of remimazolam was non-inferior to propofol.

[Level IV inferior vena cava tumor thrombus : A rare diagnosis in patients with renal cell carcinoma]

Renal cell carcinoma in combination with a supradiaphragmatic tumor thrombus is a rare tumor entity. Radical surgery including nephrectomy and thrombectomy is still considered standard treatment. The extent of the tumor thrombus should be preoperatively evaluated by MRI and TEE. An interdisciplinary team is important for surgery planning and realization. Despite the known risks of an operation, a longer overall survival is achieved.

Thrombolyse während der kardiopulmonalen Reanimation

Between 40 and 90 cardiopulmonary resuscitations are performed per 100,000 inhabitants each year in western industrialised nations. In 50-70% of these patients, either fulminant pulmonary embolism or acute myocardial infarction is the underlying cause of cardiac arrest. Based on this fact, thrombolysis may represent a new and effective causal therapeutic strategy in patients suffering from cardiac arrest due to acute myocardial infarction or fulminant pulmonary embolism. In the past, thrombolysis was contraindicated during cardiopulmonary resuscitation due to great fears of severe bleeding complications (resuscitation-mediated or lysis-induced intracerebral bleeding). For a long time, only clinical case reports or small clinical case series were reported in the literature, however, recently, the first clinical studies focusing on the safety and efficacy of thrombolytic therapy during out-of-hospital cardiopulmonary resuscitation have been published. Besides a specific therapeutic causal effect on pulmonary artery emboli and coronary artery thrombosis, experimental data strongly indicate that thrombolysis might also have an impact on cerebral microcirculatory reperfusion during and after cardiopulmonary resuscitation. This effect might be responsible for the exceptionally good neurological outcome observed in patients treated with thrombolytic agents during cardiopulmonary resuscitation and might be a result of the proven imbalance of the endogenous coagulation system in patients suffering from cardiac arrest. This coagulation imbalance is thought to be responsible for postresuscitation cerebral microcirculatory reperfusion disorders in patients after cardiac arrest and cardiopulmonary resuscitation. In summary, recent clinical and experimental data focusing on thrombolysis during cardiopulmonary resuscitation strongly indicate, that thrombolysis may represent a new and relatively safe therapeutic option during resuscitation after cardiac arrest due to acute myocardial infarction or fulminant pulmonary embolism. If the results of an international randomised, controlled clinical multicentre trial presently underway confirm the previous clinical findings, thrombolysis during cardiopulmonary resuscitation could become an important part of future cardiopulmonary resuscitation algorithms.

The Anesthesia Preoperative Evaluation Clinic (APEC): a prospective randomized controlled trial assessing impact on consultation time, direct costs, patient education and satisfaction with anesthesia care

AIM

Anesthetic preoperative evaluation clinics (APECs) are relatively new institutions. Although cost effective, APECs have not been universally adopted in Europe. The aim of this study was to compare preoperative anesthetic assessment in wards with an APEC, assessing time, information gain, patient satisfaction and secondary costs.

METHODS

Two hundred and seven inpatients were randomized to be assessed at the APEC or on the ward by the same two senior anesthetists. The outcomes measured were the length of time for each consultation, the amount of information passed on to patients and the level of patient satisfaction. The consultation time was used to calculate impact on direct costs. A multivariate analysis was conducted to detect confounding variables.

RESULTS

Ninety-four patients were seen in the APEC, and 78 were seen on the ward. The total time for the consultation was shorter for the APEC (mean 8.4 minutes [P<0.01]), and we calculated savings of 6.4 Euro per patient. More information was passed on to the patients seen in the APEC (P<0.01). The general satisfaction scores were comparable between groups. A multivariate analysis found that the consultation time was significantly influenced by the type of anesthesia, the magnitude of the operation and the location of the consultation. Gain in information was significantly influenced by age, education and the location of the visit.

CONCLUSION

The APEC reduced consultation times and costs and had a positive impact on patient education. The cost savings are related to personnel costs and, therefore, are independent of other potential savings of an APEC, whereas global patient satisfaction remains unaltered.

First-aid sensor system: new methods for single-point detection and analysis of vital parameters such as pulse and respiration

The paper describes a first aid medical sensor system that is able to detect pulse and respiration. According to an opinion poll 79% of unexperienced first aiders were looking forward to use a system that supports them in first aid situations. Such a device has to be reliable and available in everyday use (e.g. as a keychain or in a first-aid kit). Therefore we investigated a single point sensor that is able to detect both respiration and blood flow at the same point of the body, for instance on the neck. Compared to ECG-derived methods absent pulse due to pulseless electrical activity (PEA) will be recognized as such. Tests have shown that the sensor can also be used to detect deglutition and other body motion sequences.

[Dolasetron and shivering. A prospective randomized placebo-controlled pharmaco-economic evaluation]

BACKGROUND AND GOAL

Forced by the current economical situation, German hospitals have to reconsider their clinical productivity. When caregivers introduce new therapeutic concepts medical quality should either be improved without increasing costs or when reducing costs medical quality should be maintained. In the surgical field postoperative shivering reduces both patient comfort and medical quality. We therefore investigated the clinical pathway prevention of shivering with dolasetron in a prospective, randomized, placebo-controlled analysis of cost-effectiveness.

MATERIAL AND METHODS

After written informed consent we randomized 40 patients scheduled for lumbar disc hernia repair or head and neck surgery into two groups: patients of group D received dolasetron 1 mg/kg body weight during surgery whereas patients of group K received 100 ml saline as placebo. Primary endpoints were the incidence of shivering, the length of stay in the postanesthesia care unit and process-associated costs. Secondary endpoint was the influence on perioperative thermoregulation.

RESULTS

We observed postanesthetic shivering in 5 patients belonging to group D in comparison to 15 patients receiving the placebo (p<0.05). The length of stay in the postanesthesia care unit was shorter in patients allocated to dolasetron (mean+/-SD; group D: 43+/-16 min, group K 62+/-18 min, p<0.05). There was a significant saving in process-associated personnel costs (personnel costs in group D EUR 41.26+/-14, personnel costs in group K EUR 53.15+/-15) but in contrast the process-associated material costs were significantly increased (group D EUR 17.16+/-3, group K EUR 0.73+/-1, p<0.05).

CONCLUSIONS

The optimization of the clinical process and medical quality induced by a prophylaxis against shivering and postoperative nausea and vomiting compensates for the increased use of pharmaceutical resources in our setting.

Nichtinvasives erweitertes hämodynamisches Monitoring

BACKGROUND

Cardiac output and the cardiac index (CI) are not routinely monitored during major abdominal surgery for economic as well as medical reasons. This practice, however, might be changed by the application of newer non-invasive technologies like the partial CO(2) rebreathing method based on the inverse Fick's principle. In this prospective randomized study we investigated the impact of a non-invasive monitoring of CI on the incidence of hemodynamic instability and interventions by the attending anesthesiologist during major abdominal surgery.

PATIENTS AND METHODS

Additionally to routine hemodynamic monitoring we measured CI using the partial CO(2) rebreathing method in 28 patients (9 female, 19 male) undergoing major abdominal surgery. In group I the anesthesiologists were aware of the results of the extended hemodynamic monitoring and in group II the attending anesthesiologist was blinded to the information obtained by these measurements of CI.

RESULTS

Groups did not differ with regard to the baseline hemodynamic parameters. We obtained 923 measurements in both groups and 95 situations of hemodynamic instability (CI<2.5 l/minxm(2)) were detected in group I compared to 147 situations in group II (p<0.05). There were significantly more hemodynamic interventions in group I than in group II (p<0.0001). The cardiac index remained higher in group I in comparison to group II (p<0.0001). Measurement of CI was the only method to detect situations of hemodynamic instability in our setting.

CONCLUSION

The incidence of hemodynamic instability was significantly reduced during major abdominal surgery when anesthesiologists were aware of the measurement results of extended hemodynamic monitoring.

Larynxmaske

Introduction of the laryngeal mask airway (LMA) has been a revolutionary development in airway management over the last decades. It was first used clinically in 1981 by A. Brain and has been widely used in Germany since 1990. Originally intended as a substitute for conventional mask respiration for short periods of general anaesthesia, the laryngeal mask is in the meantime used in many areas as an alternative to elective endotracheal intubation as well as an option for controlling difficult airways. This contribution provides an overview of the basics as well as practical aspects of LMA use, and discusses the possibilities and limitations of the laryngeal mask in daily practice.

Association between early postoperative coagulation activation and peri-operative myocardial ischaemia in patients undergoing vascular surgery

We investigated the association of peri-operative myocardial ischaemia with activation of coagulation and endogenous fibrinolysis in patients undergoing vascular surgery. In 50 patients, continuous Holter monitoring was performed to assess peri-operative myocardial ischaemia and 12-lead electrocardiography was recorded preoperatively and 72 h postoperatively to assess myocardial infarction. Serial blood samples were drawn peri-operatively to determine the concentrations of fibrin monomers (for activation of coagulation), D-dimer (for endogenous fibrinolysis) and cardiac troponin T and I. Patients with myocardial ischaemia showed higher concentrations of fibrin monomers at 48 h, and higher concentrations of d-dimer preoperatively and at 24 and 48 h postoperatively. In patients with peri-operative myocardial ischaemia, strong positive correlations were observed between fibrin monomer and D-dimer concentrations at 15 min and 4 h postoperatively, and cardiac troponins at 15 min and at 4, 24, 48 and 72 h postoperatively. Early postoperative activation of coagulation and fibrinolysis is associated with peri-operative myocardial cell damage among patients who are at risk for, or have a history of, coronary artery disease plus peri-operative myocardial ischaemia.

Atemwegsmanagement bei der Ein-Lungen-Ventilation

The progress in sophisticated and complex operating methods for intrathoracic procedures demands reliable lung separation with the possibility of one-lung ventilation. Patients with thoracic traumas and pulmonary emergencies can confront any anaesthesiologist with the need for lung separating procedures. This review describes the contemporary procedures for lung separation. The special aspects of difficult airway management during one-lung ventilation and the indications for one-lung ventilation are described in detail. The pathophysiological changes during one-lung ventilation and strategies to avoid hypoxemia and to preserve adequate oxygenation are discussed.

Eine faktorielle Studie von 6 Interventionen zur Vermeidung von �belkeit und Erbrechen nach Narkosen

BACKGROUND

Untreated, one third of patients who undergo surgery will have postoperative nausea and vomiting. Although many trials have been conducted, the relative benefits of prophylactic antiemetic interventions given alone or in combination remain unknown.

METHODS

In a randomized, controlled trial of factorial design, 5,199 patients at high risk for postoperative nausea and vomiting were randomly assigned to 1 of 64 possible combinations of 6 prophylactic interventions: 1) 4 mg of ondansetron or no ondansetron; 2) 4 mg of dexamethasone or no dexamethasone; 3) 1.25 mg of droperidol or no droperidol; 4) propofol or a volatile anesthetic; 5) nitrogen or nitrous oxide; 6) remifentanil or fentanyl. The primary aim parameter was nausea and vomiting within 24 h after surgery, which was evaluated blindly.

RESULTS

Ondansetron, dexamethasone, and droperidol each reduced the risk of postoperative nausea and vomiting by about 26%, propofol reduced the risk by 19%, and nitrogen by 12%. The risk reduction with both of these agents (i.e., total intravenous anesthesia) was thus similar to that observed with each of the antiemetics alone. All the interventions acted independently of each other and independently of the patients' baseline risk. Consequently, the relative risks associated with the combined interventions could be estimated by multiplying the relative risks associated with each intervention. However, absolute risk reduction was a critical function of patients' baseline risk.

CONCLUSIONS

Because antiemetic interventions are similarly effective and act independently, the safest or least expensive should be used first. Prophylaxis is rarely warranted in low-risk patients, moderate-risk patients may benefit from a single intervention, and multiple interventions should be reserved for high-risk patients.

Postoperative 12-lead ECG predicts peri-operative myocardial ischaemia associated with myocardial cell damage

Peri-operative myocardial ischaemia is the single most important risk factor for an adverse cardiac outcome after non-cardiac surgery. The present study examines whether intermittent 12-lead ECG recordings can be used as an early warning tool to identify patients suffering from peri-operative myocardial ischaemia and subsequent myocardial cell damage. Fifty-five vascular surgery patients at risk for or with a history of coronary artery disease were monitored for peri-operative myocardial ischaemia using intermittent 12-lead ECG recordings taken pre-operatively and at 15 min, 20 h, 48 h, 72 h and 84 h postoperatively. The effectiveness of the 12-lead ECG was gauged by examining concordance with continuous 3-channel Holter monitoring and capturing peri-operative myocardial ischaemia by serial analyses of creatine kinase myocardial band isoenzyme and cardiac troponin T and I. The incidence of peri-operative myocardial ischaemia detected by 12-lead ECG was 44% and was identifiable in most patients (88%) 15 min after surgery. The incidence of peri-operative myocardial ischaemia detected by continuous monitoring was 53%, with the most severe episodes occurring intra-operatively and during emergence from anaesthesia. The concordance of the 12-lead method with continuous monitoring was 72%. The concordance of creatine kinase myocardial band isoenzyme activity with the 12-lead method was 71% and with Holter monitoring 57%. The concordance of mass concentration of creatine kinase myocardial band with 12-lead ECG recordings was 75%, and the corresponding value for Holter monitoring was 68%. The concordance of cardiac troponin T and I levels with the 12-lead method was 85% and 87%, respectively, and concordance with Holter monitoring was 72% and 66%, respectively. The postoperative 12-lead ECG identified peri-operative myocardial ischaemia associated with subsequent myocardial cell damage in most patients undergoing vascular surgery.

Umfrage zur aktuellen Situation der Regionalan�sthesie im deutschsprachigen Raum

The practice of regional anaesthesia in German speaking countries was investigated by a survey. The last part of the trilogy contains the presentation and evaluation of the data about the methods in obstetric anaesthesia. In 2002 questionnaires were mailed to 750 randomly selected departments of anaesthesia, 384 hospitals (51.2%) responded of which 278 had an obstetric unit. Caesarean section rate was 22.5+/-8.2% and for elective caesarean section spinal anaesthesia was mostly used. General anaesthesia was never used in 58.3% of Swiss, 10.2% of German, and 21.1% of Austrian hospitals. For non-elective caesarean section 42.1% of the hospitals often used a spinal anaesthesia, and 44.8% sometimes, in Switzerland these were 92.9% and 7.1%, respectively. Pain relief for labour was usually achieved with epidural anaesthesia or drugs. The trend from general to regional anaesthesia for caesarean section is continued, as is the trend from local infiltrative techniques to epidural anaesthesia for vaginal delivery. Switzerland was in the forefront for these developments.

Propofol-Infusionssyndrom

Propofol infusion syndrome has not only been observed in patients undergoing long-term sedation with propofol, but also during propofol anesthesia lasting 5 h. It has been assumed that the pathophysiologic cause is propofol's impairment of oxidation of fatty acid chains and inhibition of oxidative phosphorylation in the mitochondria, leading to lactate acidosis and muscular necrosis. It has been postulated that propofol might act as a trigger substrate in the presence of priming factors. Severe diseases in which the patient has been exposed to high catecholamine and cortisol levels have been identified as trigger substrates. Once the development of propofol infusion syndrome is suspected, propofol infusion has to be stopped immediately and specific therapeutic measures initiated, including cardiocirculatory stabilization and correction of metabolic acidosis. To increase elimination of propofol and its potential toxic metabolites, hemodialysis or hemofiltration are recommended. Due to its possible fatal side effects, the use of propofol for long-term sedation in critically ill patients should be reconsidered. In cases of unexplained lactate acidosis occurring during continuous propofol infusion, propofol infusion syndrome must be taken into consideration.

Umfrage zur aktuellen Situation der Regionalan�sthesie im deutschsprachigen Raum

The current practice of regional anaesthesia in German-speaking countries was investigated in a survey. The second part of the trilogy presents data about its use, success rates, and techniques. In 2002 questionnaires were mailed to 750 randomly selected departments of anaesthesia of which 384 hospitals participated. Peripheral regional anaesthesia is used above all in traumatology and orthopaedics, 45% of the hospitals with paediatric surgery never used neuroaxial blocks. The residents achieved mean success rates of 69.7+/-11.8% for supraclavicular plexus block to 85.5+/-9.0% for spinal anaesthesia, the specialists in anaesthesia 79.2+/-11.3% (supraclavicular plexus block) to 91.0+/-6.8% (spinal anaesthesia). Standards for basic techniques, recording of success rates, and for quality assurance of peripheral nerve blocks should be worked out to improve the application of peripheral regional anaesthesia procedures. In neuroaxial anaesthesia satisfying success rates were reached in German-speaking countries. In paediatric anaesthesia its use still has many opponents.

Umfrage zur aktuellen Situation der Regionalan�sthesie im deutschsprachigen Raum

The practice of regional anaesthesia in German speaking countries was investigated by a survey. The first part of the trilogy contains the presentation and evaluation of the data about quality assurance and training concepts. In 2002 questionnaires were mailed to 750 randomly selected departments of anaesthesia and 384 hospitals participated (51.2%). The overall proportion of regional anaesthesia was 23% and in Switzerland it was significantly higher (adults: 48%; children: 31%). Of the hospitals 19% had no person who was responsible for quality assurance. The number of puncture attempts was unlimited in 59% of the hospitals. The first training steps were observed closely (complete observation: 81%). The exact beginning (48%) and end (15%/13%) of the training were often not fixed, 80% of all anaesthesia departments requested an improvement in the training for peripheral and 53% for neuroaxial regional anaesthesia techniques. Regional anaesthesia plays a highly important role. Concepts of training and quality assurance that are backed up by evidence-based medicine should be worked out to improve the training and further education in regional anaesthesia.

Cost-effectiveness and high patient satisfaction in the elderly: sevoflurane versus propofol anaesthesia

BACKGROUND AND OBJECTIVE

The use of propofol compared with isoflurane is associated with improved patient comfort and decreased costs. However, as the cost saving, the quicker recovery time and patient comfort may not be evident if sevoflurane is substituted for isoflurane; these two anaesthetic agents were analysed in elderly patients.

METHODS

In a prospective randomized study, 96 patients undergoing elective ophthalmic surgery received either total intravenous anaesthesia with propofol (Group P), propofol for induction and sevoflurane for maintenance (Group P/S) or sevoflurane for inhalation induction and maintenance (Group S). Analyses focussed on haemodynamics, the quality of recovery, and the costs for the anaesthetic and the entire procedure.

RESULTS

Bradycardia or hypotension, mainly registered in Groups P and P/S, did not influence patients' recovery. In Group S, postoperative nausea and vomiting occurred frequently, and 50% of patients complained of discomfort during induction. In Group P/S, the costs for anaesthetics and total costs were lower than those in Groups P and S.

CONCLUSIONS

Propofol- and sevoflurane-based maintenance of anaesthesia were similar with regard to patient comfort and recovery in the elderly. Cost analysis revealed that it was less expensive to use propofol for induction and sevoflurane for maintenance than to use either propofol or sevoflurane as sole agents for anaesthesia.

Cerebral and extracerebral release of protein S100B in cardiac surgical patients

Although several clinical studies have shown that increased serum concentrations of protein S100B predict ischaemic brain damage after cardiac surgery, S100B may also be released from the heart or other injured tissue. We therefore investigated the correlation between serum S100B levels and those of the specific cardiac marker troponin I in order to assess the cerebral vs. extracerebral origin of S100B. In 64 cardiac surgical patients, serial blood samples were drawn for the measurement of S100B and troponin I before surgery and for seven days after surgery. Neurological function was assessed before with the National Institutes of Health Stroke Scale and the Folstein Mini Mental Test. The data show that a sustained increase in serum S100B levels is associated with neurological dysfunction, as witnessed by a positive correlation between S100B values and the results of the neuropsychological tests. In contrast, the early postoperative increased levels of protein S100B derive from cardiac tissue, as shown by the positive correlation between S100B and cardiac troponin I levels.

Real-time ultrasonic observation of combined spinal-epidural anaesthesia

BACKGROUND AND OBJECTIVE

The quality of combined spinal-epidural anaesthesia mainly depends on accurate identification of the epidural space. The real-time ultrasound control of the procedure for puncture was therefore evaluated.

METHODS

Thirty parturients scheduled for Caesarean section were randomized to three equal groups. Ten control patients received conventional combined spinal-epidural anaesthesia. Ten of the remaining patients received ultrasonic scans by an offline scan technique, and 10 received online imaging of the lumbar region during epidural puncture. The epidural space was identified and needle advancement was surveyed through the interspinal and flaval ligaments. The number of attempts to advance the needle to achieve a successful puncture was measured and compared, as well as the number of vertebral interspaces punctured before successful entry into the epidural space.

RESULTS

There was no difference between patient characteristics in the three groups. The visualization of the epidural structures and of the needle manipulations was very effective. In the ultrasound group, the reduction in the number of attempts at puncture was significant (P < 0.036). The number of interspaces necessary for puncture was reduced (P < 0.036) in the ultrasound online group compared with controls. The number of spinal needle manipulations was significantly reduced (P < 0.036).

CONCLUSIONS

Real-time ultrasonic scanning of the lumbar spine is an easy procedure. It provides an accurate reading of the location of the needle tip and facilitates the performance of combined spinal-epidural anaesthesia.

[Drug interactions and the anesthesiologist]

Eines der Grundprinzipien der modernen Anästhesie ist die Kombination unterschiedlicher Pharmaka aus verschiedenen Substanzgruppen. Zusätzlich sehen sich Anästhesisten häufig mit der umfangreichen medikamentösen Dauertherapie chronisch kranker Patienten konfrontiert. Werden zwei oder mehrere Medikamente gleichzeitig appliziert, kann sich der pharmakologische Effekt von der Summe der einzeln verabreichten Substanzen unterscheiden. Das kann erwünscht, aber für den Patienten auch potenziell gefährlich sein. Die Wahrscheinlichkeit einer unerwünschten Arzneimittelwechselwirkung steigt exponentiell mit der Anzahl der verabreichten Medikamente und kann sowohl auf pharmazeutischer, pharmakodynamischer wie pharmakokinetischer Ebene entstehen. Obwohl die Fülle der Interaktionsmöglichkeiten enorm und die Komplexität der Arzneimittelwechselwirkungen schwer greifbar und zu identifizieren sind, gelten ernsthafte Medikamenteninteraktionen in der Anästhesie allgemein als vorhersehbar. Neben der Erkennung der Risikofaktoren wie Leber- und Niereninsuffizienz, ASA-Status sowie metabolische und endokrine Veränderungen des Patienten sind grundlegende Kenntnisse und ein Verständnis der allgemeinen und speziellen Pharmakologie notwendig, um unerwünschte Arzneimittelwechselwirkungen zu verhindern.

Entwicklung eines Fragebogens zur Erfassung der Qualit�t der Narkoseaufkl�rung

In the current study a questionnaire was developed to evaluate the preanesthetic visit to prepare patients for general anesthesia with regard to the effects on in-hospital quality of care. The questionnaire consists of one part pertaining to patient satisfaction and one part pertaining to the information gained from the preanesthetic visit. In a first phase, the questionnaire was generated and then validated in 104 patients undergoing general or vascular surgery at the University of Heidelberg, Germany. As a result of the pretest evaluation, the preliminary pool of questions could be reduced. Consequently, the final questionnaire is composed of six questions on patient satisfaction and six questions on information gained after the preanesthetic visit as well as one question regarding the number of preanesthetic consultations prior to general anesthesia. In the part of the questionnaire on patient satisfaction, responses can be given on a 6-point scale ranging from -3 (statement is not correct) to +3 (statement is correct). The scores -3 to +3 are assigned 1-6 points, in order to calculate a total sum score to measure patient satisfaction. The part on information gained contains multiple-choice questions with four possible answers, of which only one is correct. Analogous to the measurement of patient satisfaction, a total sum score can be calculated to evaluate the information gain after the preanesthetic visit. The present study shows the suitability of a questionnaire to evaluate the quality of health care after the preanesthetic visit with the parameters patient satisfaction and information gain. Such a questionnaire can be used to compare different premedication techniques and, thus, might contribute to improve the quality of health care.

[Accessible price lists at the anaesthesiologist's workplace enhance cost consciousness as a part of process and cost optimization]

The imminent introduction of the DRG (diagnosis-related-group) system is putting hospitals in Germany under considerable pressure. This requires that personnel are efficiently allocated by optimizing organizational procedures and that the limited resources be distributed in a cost-effective manner. One prerequisite for this is a marked cost-consciousness on the part of those who "incur costs" in providing a service. To increase the awareness of costs in clinical physicians, the cost structures must be transparent. In order to achieve this goal, a project was initiated at the Department of Anaesthesiology at the University Hospital of Heidelberg, which aimed to enhance the cost-consciousness of the staff by making price lists available to anaesthesiologists at the workplace. In addition to the price lists, the 25 most expensive medications and medical products were added as an ABC analysis. The departmental staff was interviewed by questionnaire as to whether this project was reasonable. After 1 year the interview was repeated. The results of the questionnaire showed that in the opinion of the staff, price lists are an effective tool, as cost-consciousness on the part of clinical physicians can be enhanced by making price structures transparent. This is a major prerequisite for individual motivation in the cost-effective management. Although the ABC analyses demonstrate no long-term effect of the price-transparency on the cost structures, the staff showed increased cost-consciousness and individual motivation for economic tasks.

[Emergency from anesthesia in small children. From laryngospasm to prolonged apnea]

Postoperative laryngospasm during emergence from anaesthesia represents a potentially life-threatening complication. Even if this is successfully overcome using drug therapy, new, serious problems may develop. We report the case of a 3 1/2 -year-old boy of African descent weighing 15 kg who developed a laryngospasm during emergence from anaesthesia. Because the airway obstruction could not be controlled by deepening the anaesthesia again and administering anti-obstructive drugs, the boy was given 15 mg succinylcholine. Thereafter prolonged apnea developed such that the patient had to be admitted to the pediatric intensive care unit. The child was extubated 6 h later and the further course was normal so that he could be released from the hospital the following day. Further diagnostic study revealed a dibucaine-sensitive, fluoride-resistant pseudocholinesterase in the plasma, which is a rare form of atypical pseudocholinesterase, explaining the prolonged arousal phase after the administration of succinylcholine. Three significant aspects of this case are discussed: 1. risk factors and treatment of perioperative airway obstruction 2. factors and treatment of prolonged apnea, and 3. delayed arousal reactions and their management in an outpatient setting.

[Ultrasound and local anaesthesia. Part III: ultrasound and neuroaxial local anaesthesia]

The use of ultrasound as a diagnostic tool for the visualisation of the epidural space has effects on the quality and the performance of epidural anesthesia. This work presents an overview of the recent experiences with ultrasound for epidural anesthesia and on the possibilities for ultrasound imaging techniques. The results of visualisation of the epidural space and its limiting structures obtained by various working groups are presented. We review all presently available data on the prediction of the puncture depth. The various working groups found correlations between predicted and effective puncture depth between 0.79 and 0.98 and the precision of the measurement was 57-7.7 mm. Regarding the prediction of the puncture angle there was a poor correlation ranging between 0.07 and 0.31. The precision between the measured and the punctured angles was found to be 10-13.4 degrees. In all available prospective randomised studies on the puncture effects in the lumbar epidural space, the influence of ultrasound showed a significant reduction ( p<0.03) of the puncture attempts,and we found a significant ( p<0.05) reduction in the number of puncture levels. The ultrasound-guided puncture allowed an ideal needle trajectory and a more precise application of the catheter. A significant improvement of analgesia quality ( p<0.035) and patient satisfaction ( p<0.006) could be achieved. The metaanalysis of the different studies regarding puncture quality by ultrasound-guided peridural anaesthesia showed a clear advantage for the use of imaging techniques.

Complete recovery after 2 h of cardiopulmonary resuscitation following high-dose prostaglandin treatment for atonic uterine haemorrhage

We report the case of a 31-year-old woman who delivered twins by Caesarean section in whom atonic uterine haemorrhage developed 6 h postoperatively. During conservative treatment with the high-dose prostaglandin analogs sulprostone (PGE(2)) and dinoprost (PGF(2alpha)), acute pulmonary oedema and cardiac decompensation developed and, subsequently, the patient suffered cardiopulmonary arrest. After a 2h-period of cardiopulmonary resuscitation (CPR), it was possible to restore and stabilize circulation under the highest dose of catecholamines. Despite 2h of CPR, the patient was discharged from hospital 3 months later without any major physical or neurocognitive deficit.

Comparison of caudal and intravenous clonidine in the prevention of agitation after sevoflurane in children

BACKGROUND

In children, sevoflurane anaesthesia is associated with postanaesthetic agitation, which is treated mainly with opioids. We compared the effectiveness of epidural and i.v. clonidine in the prevention of this postanaesthetic agitation.

METHODS

Eighty children aged 3-8 yr (ASA I-II) received standardized general anaesthesia with inhaled sevoflurane and caudal epidural block with 0.175% bupivacaine 1 ml kg-1 for minor surgery. The children were assigned randomly to four groups: (I) clonidine 1 microgram kg-1 added to caudal bupivacaine; (II) clonidine 3 micrograms kg-1 added to caudal bupivacaine; (III) clonidine 3 micrograms kg-1 i.v. and caudal bupivacaine; and (IV) caudal block with bupivacaine, no clonidine (control). A blinded observer assessed the behaviour of the children during the first postoperative hour. Secondary end-points were the time to fitness for discharge from the postanaesthesia care unit, and haemodynamic and respiratory variables.

RESULTS

The incidence of agitation was 22, 0, 5 and 39% in groups I, II, III and IV respectively (P < 0.05 for groups II and III compared with group IV). During the first hour after surgery, patients in groups II and III had significantly lower scores for agitation than group IV patients. Time to fitness for discharge did not differ between the four groups.

CONCLUSIONS

Clonidine 3 micrograms kg-1 prevented agitation after sevoflurane anaesthesia, independently of the route of administration. The effect of clonidine appears to be dose-dependent, as an epidural dose of 1 microgram kg-1 failed to reduce it.

Thrombolytic therapy during cardiopulmonary resuscitation

Recently, efforts have been undertaken to investigate the effects of thrombolysis during cardiopulmonary resuscitation (CRP) in patients suffering from massive pulmonary embolism or acute myocardial infarction. In up to 70% of patients with cardiac arrest, one of these two diseases is the underlying cause of deterioration. Nevertheless, thrombolysis has not been conducted during CPR because of the fear of severe bleeding complications. However, an increasing number of clinical studies suggest that thrombolytic therapy during CPR can contribute to haemodynamic stabilisation and survival in patients with massive pulmonary embolism and acute myocardial infarction, when conventional CPR procedures have been performed unsuccessfully. Apart from the specific causal action of thrombolytic agents at the site of pulmonary emboli and coronary thrombosis, experimental data indicate that thrombolysis during CPR can improve microcirculatory reperfusion, which may be most important in the brain. In accordance with these data, marked activation of blood coagulation without adequate activation of endogenous fibrinolysis has been demonstrated early after cardiac arrest. In summary, thrombolysis during CPR is presently a treatment strategy that can be performed on an individual basis in patients with pulmonary embolism or acute myocardial infarction. It may become a routine measure if positive results of randomised, controlled clinical trials will be available in the future.

Ultrasound imaging of the thoracic epidural space

BACKGROUND AND OBJECTIVES

In thoracic epidural anesthesia, the "loss of resistance" technique is the standard technique for the identification of the epidural space (EDS), the feedback to the operator is often solely tactile. Our aim was to establish ultrasonography for the prepuncture demonstration of the anatomic structures surrounding the thoracic EDS and to evaluate its precision and imaging quality.

METHODS

We examined 20 volunteers. In each participant, the extradural space and the neighboring anatomic landmarks in the intervertebral space Th 5-6 were identified using 2 imaging techniques: magnetic resonance imaging (MRI) and ultrasonography. We compared corresponding images regarding distance measurements and the visibility of anatomic landmarks.

RESULTS

The capacity of ultrasound imaging (US) to depict the thoracic EDS was limited. Due to the better overview, MR images were easier to interpret. However, US proved to be of better value than MRI in the depiction of the dura mater. All important landmarks for the puncture of the thoracic EDS could be identified with both techniques. The overall correlation was satisfactory. US depicted the different structures of the thoracic EDS with an acceptable precision (confidence interval, 4.6 to 8.7 mm).

CONCLUSIONS

US showed good correlation with MRI, which is a standard imaging technique for the depiction of the spine. We anticipate that prepuncture ultrasonography may facilitate thoracic epidural anesthesia by needle placement.

[The visualisation of dura perforation and blood patches with ultrasound]

The postdural puncture headache (PDPH) is a possible complication after spinal or epidural puncture. The therapeutic concept is usually organised step by step, but the epidural blood patch is the most reliable and effective therapy. In earlier studies myelographie, epidurographie and MRT were used, to visualise the localisation of the dural defect and to describe the effects of patching the epidural space. Our working group focused on the utilisation of ultrasound and we decided to use this technique for the visualisation of bloodpatches. With agreement of the local ethics committee we monitored the performance of 4 epidural bloodpatches in pregnant women, who suffered from PDPH. We used a General Electric LQ 400 ultrasonograph with a 7-MHz-probe. To ensure sterile conditions we used sterile ultrasound sleeves and sterile ultrasound gel. In 3 of 4 cases a continuity loss could be represented in the doppel layer signal of the dura. It had the size of the diameter of a Tuohy needle. In one case the defect of the dura was larger than in the preliminary investigations (2,5 - 3 mm). The ultrasonography of the epidural space was performed in the paramedian scan. All patches were placed by using the conventional loss of resistance technique with using online ultrasound support. The epidural puncture and the application of the blood patches were visualised simultaneously in all cases. With the injection of blood a brief expansion of the epidural space was seen. The patients recieved a mean injection volume of 17 ml sterile blood. 10 to 40 seconds after the injection of blood the disconituity of the dura doppel layer signal was no longer provable. Within a short time we could detect the increase of cerebrospinal fluid and the patients headache was treated sucessfully. The clinical use of this diagnostic technique can be found in the simultaneous presentation of the dura leakage and the intervention while performing an epidural bloodpatch. Since these informations are relevant for further clinical practice further investigations are warranted.

[Contribution of anesthesia to workflow operation]

The changes in our health care system caused by the introduction of DRGs make it necessary for us to abandon departmental process structures in favour of total hospital orientated process structures. An interdisciplinary approach is crucial to enable the most effective use of personnel and material resources. Future orientated information technology and organisational structures will enable us to process our patients effectively and efficiently from pre-admission to discharge. Anaesthesia has to be integrated into a patient management system for in- and out-patients. The essential matters for consideration are anaesthesia consulting hours, the common establishment of process structures for preoperative care, operation room management and postoperative patient care. Routine controls and analysis of the required teamwork reveal improvement potential and enable us to use the necessary control elements effectively.

Colour Doppler imaging of the interspinous and epidural space

BACKGROUND AND OBJECTIVE

In recent studies, ultrasonic diagnostic imaging has proved useful in the screening of the trajectory of the epidural needle. With regard to possible side-effects of spinal and epidural anaesthesia caused by vessel injury, we aimed to evaluate the usability of Colour Doppler imaging for the depiction of interspinous vessels in prepuncture examination.

METHODS

Ultrasonic examination of the L3/4 interspace area was performed in 20 volunteers. Using a 4-MHz and a 7-MHz probe with B-mode and Colour Doppler imaging, respectively, we compared four settings for the quality of vessel depiction in the puncture area. Overall resolution was evaluated according to the distinction of landmarks. Vascular structures were identified by pulsation (B-mode) or blood flow (Doppler).

RESULTS

Colour Doppler imaging of the L3/4 interspace was unachievable using the 7-MHz transducer. Vessel detection was possible in 50% of the B-mode images and in all of the 4-MHz Doppler images. Vessels were perceptible from a diameter of 0.5 mm. Veins were the predominantly visible structures. Overall vessel visibility was best using 4-MHz Colour Doppler.

CONCLUSIONS

Prepuncture Doppler imaging can provide the epiduralist with information regarding the position of vessels in the needle trajectory. This might help to reduce complications in regional anaesthesia.

Paramedian access to the epidural space: the optimum window for ultrasound imaging

STUDY OBJECTIVE

To establish a useful ultrasonic approach to the epidural space so as to optimize pre-puncture diagnostics.

DESIGN

Prospective study.

SETTING

University clinic.

PATIENTS

60 participants (19 to 34 years of age), 40 healthy volunteers (20 male, 20 female) and 20 parturients.

INTERVENTIONS

Ultrasound scanning of the lumbar spine was performed at the L(3)-L(4) vertebral interspace. Three ultrasound planes were employed: the transverse, median, and paramedian longitudinal approaches.

MEASUREMENTS

We compared the width of the ultrasound-permeable area in the median and paramedian planes and assessed the visibility of the epidural space and its surrounding structures.

MAIN RESULTS

In the paramedian plane, the permeable window was larger (p < 0.001) than in the median approach. The visibility of the ligamentum flavum (p < 0.0001), dura mater (p < 0.0001), and cauda equina (p < 0.0001) was significantly higher. Pulsation of epidural vessels could be observed more frequently (p < 0.0001) in the paramedian plane.

CONCLUSIONS

The longitudinal paramedian plane provided information about the epidural space depth in excellent imaging quality. The additional information might be beneficial in epidural anesthesia and in other clinical specialties (e.g., neurosurgery, trauma care).

Astroglial protein S-100 is an early and sensitive marker of hypoxic brain damage and outcome after cardiac arrest in humans

BACKGROUND

The results of early conventional tests do not correlate with cerebral outcome after cardiac arrest. We investigated the serum levels of astroglial protein S-100 as an early marker of brain damage and outcome after cardiac arrest.

METHODS AND RESULTS

In 66 patients undergoing cardiopulmonary resuscitation after nontraumatic cardiac arrest, blood samples for the evaluation of S-100 were drawn immediately after and 15, 30, 45, and 60 minutes; 2, 8, 24, 48, and 72 hours; and 7 days after initiation of cardiopulmonary resuscitation. Moreover, the serum levels of neuron-specific enolase were determined between 2 hours and 7 days. If patients survived for >48 hours, brain damage was assessed by a combination of neurological, cranial CT, and electrophysiological examinations. Overall, 343 blood samples were taken for the determination of S-100. Maximum S-100 levels within 2 hours after cardiac arrest were significantly higher in patients with documented brain damage (survivors and nonsurvivors, 3.70+/-0.77 microg/L) than in patients without brain damage (0.90+/-0.29 microg/L). Significant differences between these 2 groups were observed from 30 minutes until 7 days after cardiac arrest. In addition, the positive predictive value of the S-100 test at 24 hours for fatal outcome within 14 days was 87%, and the negative predictive value was 100% (P<0.001). With regard to neuron-specific enolase, significant differences between patients with documented brain damage and those with no brain damage were found at 24, 48, and 72 hours and 7 days.

CONCLUSIONS

Astroglial protein S-100 is an early and sensitive marker of hypoxic brain damage and short-term outcome after cardiac arrest in humans.

The lumbar epidural space in pregnancy: visualization by ultrasonography

Epidural anaesthesia is an important analgesia technique for obstetric delivery. During pregnancy, however, obesity and oedema frequently obscure anatomical landmarks. Using ultrasonography, we investigated the influence of these changes on spinal and epidural anatomy. We examined 53 pregnant women who were to receive epidural block for vaginal delivery or Caesarean section. The first ultrasound imaging was performed immediately before epidural puncture; the follow-up scan was done 9 months later. The ultrasound scan of the spinal column was performed at the L3/4 interspace in transverse and longitudinal planes, using a Sonoace 6000 ultrasonograph (Kretz, Marl, Germany) equipped with a 5.0-MHz curved array probe. We measured two distances from the skin to the epidural space: the minimum (perpendicular) and the maximum (oblique) needle trajectory. The quality of ultrasonic depiction was analysed by a numerical scoring system. An average weight reduction of 12.5 kg had occurred by the follow-up examination. During pregnancy, the optimum puncture site available on the skin for epidural space cannulation was smaller, the soft-tissue channel between the spinal processes was narrower, and the skin-epidural space distance was greater. The epidural space was narrower and deformed by the tissue changes. The visibility of the ligamentum flavum, of the dura mater and of the epidural space decreased significantly during pregnancy. Nevertheless, ultrasonography offered useful pre-puncture information. Thus far, palpation has been the only available technique to facilitate epidural puncture. Ultrasound imaging enabled us to assess the structures to be perforated. We anticipate that this technique will become valuable clinically.

Efficacy and safety of thrombolytic therapy after initially unsuccessful cardiopulmonary resuscitation: a prospective clinical trial

BACKGROUND

During cardiopulmonary resuscitation (CPR), thrombolysis can help to stabilise patients with pulmonary embolism and myocardial infarction. Moreover, thrombolysis during CPR has beneficial effects on cerebral reperfusion after cardiac arrest. We investigated this new therapeutic approach in patients in whom conventional CPR had been unsuccessful.

METHODS

We assessed, in a prospective study, patients undergoing CPR after out-of-hospital cardiac arrest for cardiological reasons in whom return of spontaneous circulation was not achieved within 15 min. According to the Ustein criteria, our control group consisted of patients who were assessed during 1 year. After this year patients were treated with a bolus of 5000 U of heparin and 50mg, over 2 min, of tissue-type plasminogen activator (rt-PA treated group). This intervention was repeated if return of spontaneous circulation was not achieved within the following 30 min. For controls only CPR was given.

FINDINGS

Overall, 90 patients were included; heparin and rt-PA were given to 40 patients. There were no bleeding complications related to the CPR procedures. Of the rt-PA group, 68% (27) had return of spontaneous circulation and 58% (23) were admitted to a cardiac intensive care unit, compared with 44% (22; p=0.026) and 30% (15; p=0.009) of the controls, respectively. At 24 h after cardiac arrest a larger proportion of the rt-PA group than of the controls was alive (35% [14] vs 22% [11], p=0.171), and 15% (six) of rt-PA-treated patients and 8% (four) of controls could be discharged from hospital.

INTERPRETATION

After initially unsuccessful out-of-hospital CPR, thrombolytic therapy combined with heparin is safe and might improve patient outcome. On the basis of our data a randomised controlled trial might be regarded as ethical.

N-acetylcysteine induces shedding of selectins from liver and intestine during orthotopic liver transplantation

In orthotopic liver transplantation (OLT), N-acetylcysteine (NAC) reduces ischaemia/reperfusion (I/R) injury, improves liver synthesis function and prevents primary nonfunction of the graft. To further elucidate the mechanisms of these beneficial effects of NAC, we investigated influence of high-dose NAC therapy on the pattern of adhesion molecule release from liver and intestine during OLT. Nine patients receiving allograft OLT were treated with 150 mg NAC/kg during the first hour after reperfusion; 10 patients received the carrier only. One hour after reperfusion, samples of arterial, portal venous and hepatic venous plasma were taken and blood flow in the hepatic artery and the portal vein was measured. Absolute concentrations of sICAM-1, sVCAM-1, sP-selectin and sE-selectin were not markedly different. However, balance calculations showed release of selectins from NAC-treated livers as opposed to net uptake in controls (P < or = 0.02 for sP-selectin). This shedding of selectins might be a contributing factor to the decrease in leucocyte adherence and improved haemodynamics found experimentally with NAC-treatment.

[Ultrasonography and peridural anesthesia. Technical possibilities and limitations of ultrasonic examination of the epidural space]

Epidural anaesthesia (EA) is the most important analgesia technique in obstetrics for delivery. In pregnancy, hormonal adjustments lead to an alteration of tissue consistency, which often causes an early, untimely loss of resistance. Apart from mere inspection and palpation, no useful diagnostic method prior to EA performance has been established yet. In this prospective study, we examined 100 pregnant women, who had been admitted for childbirth and were undergoing epidural block (level L3-L4) for delivery. Sonotopography of the lumbar epidural structures was performed directly before epidural puncture and childbirth. We evaluated the visibility of all anatomical structures and compared all distances measured by ultrasonography and during puncture. The correlation between distances measured by ultrasound and by puncture needle was high (r2 = 0.79). No obvious dependency was found between ultrasonic and puncture angle (r2 = 0.19). The temporal distance from ultrasonic examination and puncture causes unavoidable differences: each deviation between ultrasound and puncture conditions causes a modification of the puncture depth. The patient acceptance of the procedure was very good. Ultrasonography offers the possibility to determine site and direction of epidural puncture and distance of the epidural space to the skin even before the puncture attempt. The ultrasound controlled EA for delivery can easily be inserted into the clinical routine. Ultrasonography can fill an important diagnostic gap in regional anaesthesia.

[Computer simulation and pharmacoeconomics. Computer simulation as an aid for the analysis of operating room efficiency: an example]

In this study we compared operating room (OR) efficiency of total intravenous anaesthesia (TIVA) with remifentanil and propofol and balanced anaesthesia (BAL) with fentanyl and isoflurane in cataract surgery using computersimulation. We simulated patient flow for one OR and for three ORs. Time intervals of patient flow were randomly generated from the results of a prospective, randomized trial. Both for one and for three ORs, the postanaesthesia care unit (PACU) finished earlier and one additional case per OR and per day could be performed when TIVA was used for the procedures. Overtime in the PACU was less after TIVA. With a workload of 13 or 15 operations per day in three ORs, monitoring equipment for an additional patient in the PACU was required when BAL was used. TIVA with remifentanil and propofol was associated with more OR efficiency than balanced anaesthesia with fentanyl and isoflurane when given for cataract surgery.

[Cisatracurium in coronary bypass operations--a comparison with pancuronium. Hemodynamic and neuromuscular effects in patients under chronic beta blocker treatment]

OBJECTIVE

The aim of the study was to compare haemodynamic and neuromuscular effects of cisatracurium and pancuronium in patients undergoing coronary artery bypass grafting (ASA III, good or moderately impaired LV function) who were chronically medicated with beta-adrenergic blocking agents.

METHODS

60 Patients were randomly assigned in a double-blind fashion to receive sufentanil/midazolam/etomidate and either pancuronium (2xED95, group P) or cisatracurium (2xED95, group C2 and 4xED95, group C4). Haemodynamic variables were measured using arterial and pulmonary arterial catheters, neuromuscular transmission was measured using electromyography.

RESULTS

The heart rate was significantly lower in group C2 (50.2 +/- 6.8 bpm) and in group C4 (54.3 +/- 11 bpm) than in the pancuronium group (62.4 +/- 13.2 bpm) 3 min after induction of anaesthesia and until 60 min after induction. None of the other haemodynamic parameters showed any difference between groups. Onset time was 5.22 +/- 3.43 min in group P, 6.42 +/- 2.1 min in group C2 and 2.92 +/- 1.2 min in group C4.

CONCLUSION

Under high-dose opioid induction, bradycardia must be considered if cisatracurium is administered to cardiac surgery patients.

Psychomotor recovery in very old patients after total intravenous or balanced anaesthesia for cataract surgery

We compared psychomotor recovery after total intravenous anaesthesia (TIVA) with remifentanil/propofol and balanced anaesthesia (BAL) with etomidate/fentanyl/isoflurane in 40 patients, ASA I-III, aged > or =80 yr undergoing elective cataract surgery. Recovery times were recorded and psychomotor recovery was assessed according to simple reaction time, critical flicker fusion frequency (CFF) and short-term memory 30 min, 2 h and 1 day after surgery. Physical characteristics of patients in the two groups (19 in the TIVA group and 21 in the BAL group) were comparable. The TIVA group recovered significantly more quickly. Both groups showed a poorer psychomotor performance 30 min after surgery than at baseline assessment, but simple reaction time and short-term memory were close to baseline values 2 h after surgery. Only performance in the CFF test remained below baseline at this point. No deficits in psychomotor performance were noted on the first day after surgery. We conclude that there is only a minor deficit in psychomotor function in elderly patients 2 h after cataract surgery under general anaesthesia and that psychomotor function recovers completely by 24 h after surgery.