C. Denz

Intestinal ischaemia during cardiac arrest and resuscitation: comparative analysis of extracellular metabolites by microdialysis

Intestinal ischaemia is a major complication of shock syndromes causing translocation of bacteria and endotoxins and multiple organ failure in intensive care patients. The present study was designed to use microdialysis as a tool to monitor intestinal ischaemia after cardiac arrest and resuscitation in pigs. For this purpose, microdialysis probes were implanted in pig jejunal wall, peritoneum, skeletal muscle and brain, and interstitial fluid was obtained during circulatory arrest (induced by ventricular fibrillation) and after return of spontaneous circulation (ROSC). Cardiac arrest for 4 min caused a prolonged (60 min) reduction of blood flow in jejunal wall, muscle and brain as determined by the ethanol technique. This was accompanied by cellular damage in heart muscle and brain as indicated by increased levels of troponin-I and protein S-100, respectively. Plasma levels of glucose, lactate and choline were increased at 15-60 min following cardiac arrest. In contrast, cardiac arrest induced a rapid but variable decrease of interstitial glucose levels in all monitored organs; this decrease was followed by an increase over baseline during reperfusion. In the intestine, lactate, glutamate and choline levels were increased during ischaemia and reperfusion for 60-120 min; intestinal and peritoneal samples yielded parallel changes of lactate levels. Brain and muscle samples showed similar changes as in intestinum and peritoneum except for glutamate, which was increased in brain but not in muscle. We conclude that intestinal ischaemia occurs as a consequence of cardiac arrest and resuscitation and can be monitored by in vivo microdialysis. Comparative analysis by multi-site microdialysis reveals that the intestine is equally or even more sensitive to ischaemia than brain or muscle.

Accuracy and precision of three different methods to determine Pco2 (Paco2 vs. Petco2 vs. Ptcco2) during interhospital ground transport of critically ill and ventilated adults.

BACKGROUND Interhospital transportation of critically ill and mechanically ventilated patients represents a common, yet difficult problem. Three different methods to determine Pco2 during transport are available: arterial blood gas analysis (Paco2), end-tidal (Petco2) and transcutaneous (Ptcco2) measurement. The aim of the present study is to analyze accuracy and precision of those different methods simultaneously in critically ill and ventilated adults during interhospital transport. METHODS Patients scheduled for interhospital transport were investigated after approval of the local ethics committee in the prospective study. Pco2 was determined five times in each patient during the transport simultaneously by (1) arterial blood gas analysis (Paco2[Immediate Response Mobile Analyzer, IRMA]), (2) end-tidal (Petco2), and (3) transcutaneous (Ptcco2) measurements. The results were compared with an in-hospital reference measurement performed by an ABL 625 blood gas analyzer (Paco2[ABL625]). For statistical analysis the Bland-Altman method was used. A p < 0.05 was considered statistically significant. RESULTS One hundred seventy data sets (Paco2[IRMA], Paco2[ABL625], Petco2, Ptcco2) were obtained in 34 patients (61 years +/- 16 years old; 19 male patients, 15 female patients). The mean Paco2(ABL625) was 43.2 mm Hg +/- 8.8 mm Hg ranging from 24.9 mm Hg to 72.4 mm Hg. Bland-Altman analysis revealed a bias and precision of -0.6 mm Hg +/- 2.5 mm Hg for the arterial blood gas analysis with the mobile IRMA device and -0.6 mm Hg +/- 7.5 mm Hg for the transcutaneous measurement (p > 0.05). Bias and precision (-5.3 mm Hg +/- 6.1 mm Hg) of endexpiratory CO2-measurement differed significantly (p < 0.003) when compared with the reference. CONCLUSIONS During interhospital transport Paco2(IRMA) and Ptcco2 provide the best accuracy when compared with the reference measurement. Patients who either require a tight control of Pco2 or endured lengthy transportation could benefit greatly from the combination of expiratory capnography with mobile arterial blood gas analysis or the transcutaneous measurement of Pco2.

Hypertonic-Hyperoncotic Solutions Reduce the Release of Cardiac Troponin I and S-100 After Successful Cardiopulmonary Resuscitation in Pigs

UNLABELLED In some patients, cardiopulmonary resuscitation (CPR) can revive spontaneous circulation (ROSC). However, neurological outcome often remains poor. Hypertonic-hyperoncotic solutions (HHS) have been shown to improve microvascular conductivity after regional and global ischemia. We investigated the effect of infusion of HHS in a porcine CPR model. Cardiac arrest was induced by ventricular fibrillation. Advanced cardiac life support was begun after 4 min of nonintervention and 1 min of basic life support. Upon ROSC, the animals randomly received 125 mL of either normal saline (placebo, n = 8) or 7.2% NaCl and 10% hydroxyethyl starch 200,000/0.5 (HHS, n = 7). Myocardial and cerebral damage were assessed by serum concentrations of cardiac troponin I and astroglial protein S-100, respectively, up to 240 min after ROSC. In all animals, the levels of cardiac troponin I and S-100 increased after ROSC (P < 0.01). This increase was significantly blunted in animals that received HHS instead of placebo. The use of HHS in the setting of CPR may provide a new option in reducing cell damage in postischemic myocardial and cerebral tissues. IMPLICATIONS Infusion of hypertonic-hyperoncotic solutions (HHS) after successful cardiopulmonary resuscitation in pigs significantly reduced the release of cardiac troponin I and cerebral protein S-100, which are sensitive and specific markers of cell damage. Treatment with HHS may provide a new option to improve the outcome of cardiopulmonary resuscitation.

Cytosolic ubiquitin and ubiquitylation rates in human peripheral blood mononuclear cells during sepsis.

The ubiquitin system plays a crucial role in the immune system, and ubiquitylation is regarded as one of the most common posttranslational modifications of proteins. However, its regulation in human peripheral blood mononuclear cells during sepsis is unknown. Thus, we investigated cytosolic levels of free and conjugated ubiquitin and the total ubiquitylation rate in cell free extracts from healthy donors (n = 10) and patients (n = 10) with sepsis. During sepsis, the total ubiquitin concentration was significantly reduced (P < 0.001), which was caused by a significant decrease in conjugated ubiquitin (7.4 ± 1.9 ng vs. 11.75 ± 1.4 ng conjugated ubiquitin/μg protein, P < 0.001), whereas free ubiquitin was unchanged. The proportion between free and conjugated ubiquitin showed a linear relationship in physiologic conditions (r2, 0.76, P = 0.001) but not in sepsis (r2, 0.27, P = 0.12). These changes were accompanied by a decreased total ubiquitin protein ligase activity (1.7 ± 1.1 pkat/mg vs. 5.7 ± 2.9 pkat/mg, P = 0.002). The tight regulation of the cytosolic ubiquitin pool appears to be significantly altered during sepsis. In addition to alterations in ubiquitin turnover, these findings suggest that reduced ubiquitylation rates also contribute to the decrease in endogenous conjugated ubiquitin. This indicates that a major pathway of posttranslational protein modification in all eukaryotes is profoundly altered in peripheral blood mononuclear cells from critically ill sepsis patients. This may contribute to the well-known impairment of host defense mechanisms in sepsis.

Ökonomischer Nutzen der überlappenden Einleitung

The aim of this study was to investigate the potential economic benefit of overlapping anaesthesia induction given that all patient diagnosis-related groups (AP DRG) are used as the model for hospital reimbursement. A computer simulation model was used for this purpose. Due to the resource-intensive production process, the operating room (OR) environment is the most expensive part of the supply chain for surgical disciplines. The economical benefit of a parallel production process (additional personnel, adaptation of the process) as compared to a conventional serial layout was assessed. A computer-based simulation method was used with commercially available simulation software. Assumptions for revenues were made by reimbursement based on AP DRG. Based on a system analysis a model for the computer simulation was designed on a step-by-step abstraction process. In the model two operating rooms were used for parallel processing and two operating rooms for a serial production process. Six different types of surgical procedures based on historical case durations were investigated. The contribution margin was calculated based on the increased revenues minus the cost for the additional anaesthesia personnel. Over a period of 5 weeks 41 additional surgical cases were operated under the assumption of duration of surgery of 89+/-4 min (mean+/-SD). The additional contribution margin was CHF 104,588. In the case of longer surgical procedures with 103+/-25 min duration (mean+/-SD), an increase of 36 cases was possible in the same time period and the contribution margin was increased by CHF 384,836. When surgical cases with a mean procedural time of 243+/-55 min were simulated, 15 additional cases were possible. Therefore, the additional contribution margin was CHF 321,278. Although costs increased in this simulation when a serial production process was changed to a parallel system layout due to more personnel, an increase of the contribution margin was possible, especially with procedures of shorter duration (<120 min). For longer surgical times, the additional costs for the workforce result in a reduced contribution margin depending on the models chosen to handle overtime of the technical OR personnel. Important advantages of this approach for simulation are the use of the historical production data and the reflection of the specificities of the local situation. Computer simulation is an ideal tool to support operation room management, particularly regarding the planning of resource allocation and the coordination of workflow.

Simulationsbasierte Analyse neuer Therapieprinzipien

ZusammenfassungHintergrundDie Einführung innovativer Medikamente in der anästhesiologischen Behandlung birgt das Potenzial, perioperative Effizienzverbesserungen zu ermöglichen. Der vorliegende Beitrag untersucht die Auswirkungen der Einführung des neuen Muskelrelaxansenkapsulators Bridion in der Anästhesieausleitung auf die Leistungsfähigkeit der perioperativen Ablauforganisation.Material und MethodenZur Analyse der Auswirkungen medizinischer Innovationen wird die computergestützte Simulation als Untersuchungsmethode herangezogen. Die Simulation zeigt die Wirkungsweise von Innovationen auf die operationelle Leistungsfähigkeit sowie die entsprechenden betriebswirtschaftlichen Effekte anhand eines realitätsnahen OP-Modells und historischem Patientendatenkollektiv.ErgebnisseDer Einsatz medizinischer Innovationen in der Anästhesieausleitung kann unter bestimmten Bedingungen Ertragspotenziale für das Krankenhaus realisieren. Aufgrund kürzerer Säulenzeiten und Anästhesiepräsenzzeiten wird zusätzliches Leistungspotenzial für den OP-Bereich freigesetzt. Hieraus resultieren zusätzliche Fallzahlen im gleichen Arbeits- und Abrechnungszeitraum bis zu 2,4%.SchlussfolgerungDie Einführung innovativer Arzneimittel kann unter bestimmten Bedingungen (Verbreitungsgrad der Anwendung, Organisation des OP-Bereichs bzw. des Krankenhauses) zusätzliche leistungs- und betriebswirtschaftliche Potenziale wecken. Auf Basis der anästhesiologisch kontrollierten Zeit kann a priori keine allgemeingültige Aussage über die ökonomischen Potenziale getroffen werden. Zukünftige empirische Studien sollten die Auswirkungen auf Qualität und betriebswirtschaftlichen Nutzen für den gesamten Behandlungspfad untersuchen.AbstractBackgroundThe introduction of innovative drugs in anesthesiological treatment has the potential to improve perioperative efficiency. This article examines the impact of the new muscle relaxant encapsulator Bridion on emergence from anesthesia and on the efficiency of the perioperative organization.MethodsTo analyze the effects of medical innovations, computer simulation was used as an experimental frame. The simulation was based on a realistic model of an operating room setting and used historical data to study the effect of innovation on the operational performance and the economic outcomes.ResultsThe use of medical innovations in anesthesiological emergence yields new potentials for a hospital under certain conditions. Due to shorter block times and anesthesia-controlled times, additional benefits for the operating room could be realized. This results in an increase of up to 2.4% additional cases during similar working hours and planning periods.ConclusionThe introduction of innovative medicines may reveal more efficient and economical conditions in operating rooms. The overall result depends, for example, on the rate of application of the patient’s portfolio or the organization and access rules of the surgical suite. Based on the anesthesia-controlled time no general a priori statement about the economic potentials can be confirmed. Future empirical studies should investigate the impact on quality and economic benefits for the entire patient pathway.BACKGROUND The introduction of innovative drugs in anesthesiological treatment has the potential to improve perioperative efficiency. This article examines the impact of the new muscle relaxant encapsulator Bridion on emergence from anesthesia and on the efficiency of the perioperative organization. METHODS To analyze the effects of medical innovations, computer simulation was used as an experimental frame. The simulation was based on a realistic model of an operating room setting and used historical data to study the effect of innovation on the operational performance and the economic outcomes. RESULTS The use of medical innovations in anesthesiological emergence yields new potentials for a hospital under certain conditions. Due to shorter block times and anesthesia-controlled times, additional benefits for the operating room could be realized. This results in an increase of up to 2.4% additional cases during similar working hours and planning periods. CONCLUSION The introduction of innovative medicines may reveal more efficient and economical conditions in operating rooms. The overall result depends, for example, on the rate of application of the patients portfolio or the organization and access rules of the surgical suite. Based on the anesthesia-controlled time no general a priori statement about the economic potentials can be confirmed. Future empirical studies should investigate the impact on quality and economic benefits for the entire patient pathway.

Hypertonic-hyperoncotic solutions decrease cardiac troponin I concentrations in peripheral blood in a porcine ischemia-reperfusion model

In this study we addressed the question of whether the measurement of cardiac Troponin I (cTnI) is able to reflect beneficial effects of hypertonic-hyperoncotic solutions after transient cardiac arrest. Ten pigs were anaesthetized and cardiac arrest was induced by electric fibrillation. After 5 minutes of global ischemia, cardiac arrest was reversed by electric defibrillation. Upon return of spontaneous circulation 5 animals received hypertonic-hyperoncotic solutions (10% Hydroxyethylstarch 200/0.5 and 7.2% NaCl). The other animals received equivalent volumes of physiological saline. We observed that cTnI serum levels of animals treated with hypertonic-hyperoncotic solutions were significantly lower than those treated with saline. We conclude that hypertonic-hyperoncotic solutions may have cardioprotective effects.

Cardiac troponin I and cardiac troponin T increases in pigs during ischemia-reperfusion damage.

In this study we addressed the question of whether the measurement of cardiac Troponin T (cTnT) and cardiac Troponin I (cTnI) is able to detect myocardial cell damage in an ischemia-reperfusion model in pigs. To answer the question 3 pigs were anaesthesized and a cardiac arrest was induced by electric fibrillation. After 5 minutes of global ischemia the cardiac arrest was reversed by electric defibrillation until normal perfusion was restored. We could clearly demonstrate an increase of cTnT and cTnI 30 minutes after reperfusion indicating myocardial injury during ischemia and subsequent reperfusion. The cTnT as well as the cTnI serum levels increased till 180 minutes after reperfusion. This ischemia-reperfusion injury is likely induced by oxygen radicals generated during hypoxia and subsequent reperfusion We conclude from our first results that troponin measurements with commercial available test kits may also reflect myocardial cell damage in pigs as it was recently demonstrated in rats. Further studies are needed for correlation of troponin serum levels and histopathological damage in this model especially if it is used to test beneficial or toxicological effects of radical neutralizing drugs.

Controlling und Berichtswesen im OP-Management

The operating room (OR) is one of the most expensive facilities in most hospitals. The demands on a professional and process-oriented controlling and reporting in the OR are increased due to the increasingly more limited financial margins at the end of the diagnosis related groups (DRG) convergence phase. This study gives an overview of the current situation for cost calculation, controlling and reporting in OR management in German hospitals in 2007. The data from 69 hospitals were evaluated and this represents the largest currently available data pool on this topic.

[Economic benefits of overlapping induction: investigation using a computer simulation model].

The aim of this study was to investigate the potential economic benefit of overlapping anaesthesia induction given that all patient diagnosis-related groups (AP DRG) are used as the model for hospital reimbursement. A computer simulation model was used for this purpose. Due to the resource-intensive production process, the operating room (OR) environment is the most expensive part of the supply chain for surgical disciplines. The economical benefit of a parallel production process (additional personnel, adaptation of the process) as compared to a conventional serial layout was assessed. A computer-based simulation method was used with commercially available simulation software. Assumptions for revenues were made by reimbursement based on AP DRG. Based on a system analysis a model for the computer simulation was designed on a step-by-step abstraction process. In the model two operating rooms were used for parallel processing and two operating rooms for a serial production process. Six different types of surgical procedures based on historical case durations were investigated. The contribution margin was calculated based on the increased revenues minus the cost for the additional anaesthesia personnel. Over a period of 5 weeks 41 additional surgical cases were operated under the assumption of duration of surgery of 89+/-4 min (mean+/-SD). The additional contribution margin was CHF 104,588. In the case of longer surgical procedures with 103+/-25 min duration (mean+/-SD), an increase of 36 cases was possible in the same time period and the contribution margin was increased by CHF 384,836. When surgical cases with a mean procedural time of 243+/-55 min were simulated, 15 additional cases were possible. Therefore, the additional contribution margin was CHF 321,278. Although costs increased in this simulation when a serial production process was changed to a parallel system layout due to more personnel, an increase of the contribution margin was possible, especially with procedures of shorter duration (<120 min). For longer surgical times, the additional costs for the workforce result in a reduced contribution margin depending on the models chosen to handle overtime of the technical OR personnel. Important advantages of this approach for simulation are the use of the historical production data and the reflection of the specificities of the local situation. Computer simulation is an ideal tool to support operation room management, particularly regarding the planning of resource allocation and the coordination of workflow.