Implementation of a Bleeding Management Algorithm in Liver Transplantation: A Pilot Study.

Objectives: The aims of the study were to compare the consumption of blood products before and after the implementation of a bleeding management algorithm in patients undergoing liver transplantation and to determine the feasibility of a multicentre, randomized study. Background: Liver transplantation remains the only curative therapy for patients with end-stage liver disease, but it carries a high risk of surgical bleeding. Materials and Methods: Retrospective study of patients treated before (group 1) and after (group 2) implementation of a haemostatic algorithm guided by viscoelastic testing, including use of lyophilized coagulation factor concentrates (prothrombin complex and fibrinogen concentrates). Primary outcome was the number of units of blood products transfused in 24 h after surgery. Secondary outcomes included hospital stay, mortality, and cost. Results: Data from 30 consecutive patients was analysed; 14 in group 1 and 16 in group 2. Baseline data were similar between groups. Median total blood product consumption 24 h after surgery was 33 U (IQR: 11-57) in group 1 and 1.5 (0-23.5) in group 2 (p = 0.028). Significantly fewer units of red blood cells, fresh frozen plasma, and cryoprecipitate were transfused in group 2 versus group 1. There was no significant difference in complications, hospital stay, or in-hospital mortality between groups. The cost of haemostatic therapy was non-significantly lower in group 2 versus group 1 (7,400 vs. 15,500 USD; p = 0.454). Conclusion: The haemostatic management algorithm was associated with a significant reduction in blood product use during 24 h after liver transplantation. This study demonstrated the feasibility and provided a sample size calculation for a larger, randomized study.

Out-of-hospital deaths in Mongolia: a nationwide cohort study on the proportion, causes, and potential impact of emergency and critical care services.

Background: Little is known about the proportion and causes of out-of-hospital deaths in Mongolia. In this study, we aimed to determine the proportion and causes of out-of-hospital deaths in Mongolia during a six-month observation period before the COVID-19 pandemic. Methods: In a retrospective study, the Mongolian National Death Registry was screened for all deaths occurring from 01 to 06/2020. The proportion and causes of out-of-hospital deaths, causes of out-of-hospital deaths likely treatable by emergency/critical care interventions, as well as sex, regional and seasonal differences in the proportion and causes of out-of-hospital deaths were determined. The primary endpoint was the proportion and causes of out-of-hospital death in children and adults. Descriptive statistical methods, the Fisher's Exact, multirow Chi2-or Mann-Whitney-U-rank sum tests were used for data analysis. Findings: Five-thousand-five-hundred-fifty-three of 7762 deaths (71.5%) occurred outside of a hospital. The proportion of out-of-hospital deaths was lower in children than adults (39.3% vs. 74.8%, p < 0.001). Trauma, chronic neurological diseases, lower respiratory tract infections, congenital birth defects, and neonatal disorders were the causes of out-of-hospital deaths resulting in most years of life lost in children. In adults, chronic heart diseases, trauma, liver cancer, poisonings, and self-harm caused the highest burden of premature mortality. The proportion of out-of-hospital deaths did not differ between females and males (70.5% vs. 72.2%, p = 0.09). The proportion (all, p < 0.001; adults, p < 0.001; children, p < 0.001) and causes (adults, p < 0.001; children, p < 0.001) of out-of-hospital deaths differed between Mongolian regions and Ulaanbaatar. The proportion of out-of-hospital deaths was higher during winter than spring/summer months (72.3% vs. 69.9%, p = 0.03). An expert panel estimated that 49.3% of out-of-hospital deaths were likely treatable by emergency/critical care interventions. Interpretation: With regional and seasonal variations, about 75% of Mongolian adults and 40% of Mongolian children died outside of a hospital. Heart diseases, trauma, cancer, and poisonings resulted in most years of life lost. About half of the causes of out-of-hospital deaths could be treated by emergency/critical care interventions. Funding: Institutional funding.

Near-Infrared Spectroscopy-Guided, Individualized Arterial Blood Pressure Management for Carotid Endarterectomy under General Anesthesia: A Randomized, Controlled Trial.

Background: Differences in blood pressure can influence the risk of brain ischemia, perioperative complications, and postoperative neurocognitive function in patients undergoing carotid endarterectomy (CEA). Methods: In this single-center trial, patients scheduled for CEA under general anesthesia were randomized into an intervention group receiving near-infrared spectroscopy (NIRS)-guided blood pressure management during carotid cross-clamping and a control group receiving standard care. The primary endpoint was postoperative neurocognitive function assessed before surgery, on postoperative days 1 and 7, and eight weeks after surgery. Perioperative complications and cerebral autoregulatory capacity were secondary endpoints. Results: Systolic blood pressure (p < 0.001) and norepinephrine doses (89 (54-122) vs. 147 (116-242) µg; p < 0.001) during carotid cross-clamping were lower in the intervention group. No group differences in postoperative neurocognitive function were observed. The rate of perioperative complications was lower in the intervention group than in the control group (3.3 vs. 26.7%, p = 0.03). The breath-holding index did not differ between groups. Conclusions: Postoperative neurocognitive function was comparable between CEA patients undergoing general anesthesia in whom arterial blood pressure during carotid cross-clamping was guided using NIRS and subjects receiving standard care. NIRS-guided, individualized arterial blood pressure management resulted in less vasopressor exposition and a lower rate of perioperative complications.

Recommendations From the International Consensus Conference on Anemia Management in Surgical Patients (ICCAMS).

BACKGROUND: Perioperative anemia has been associated with increased risk of red blood cell transfusion and increased morbidity and mortality after surgery. The optimal approach to the diagnosis and management of perioperative anemia is not fully established. OBJECTIVE: To develop consensus recommendations for anemia management in surgical patients. METHODS: An international expert panel reviewed the current evidence and developed recommendations using modified RAND Delphi methodology. RESULTS: The panel recommends that all patients except those undergoing minor procedures be screened for anemia before surgery. Appropriate therapy for anemia should be guided by an accurate diagnosis of the etiology. The need to proceed with surgery in some patients with anemia is expected to persist. However, early identification and effective treatment of anemia has the potential to reduce the risks associated with surgery and improve clinical outcomes. As with preoperative anemia, postoperative anemia should be treated in the perioperative period. CONCLUSIONS: Early identification and effective treatment of anemia has the potential to improve clinical outcomes in surgical patients.

Individualized Management of Coagulopathy in Patients with End-Stage Liver Disease.

Over the last decades, individualized approaches and a better understanding of coagulopathy complexity in end-stage liver disease (ESLD) patients has evolved. The risk of both thrombosis and bleeding during minimally invasive interventions or surgery is associated with a worse outcome in this patient population. Despite deranged quantitative and qualitative coagulation laboratory parameters, prophylactic coagulation management is unnecessary for patients who do not bleed. Transfusion of red blood cells (RBCs) and blood products carries independent risks for morbidity and mortality, including modulation of the immune system with increased risk for nosocomial infections. Optimal coagulation management in these complex patients should be based on the analysis of standard coagulation tests (SCTs) and viscoelastic tests (VETs). VETs represent an individualized approach to patients and can provide information about coagulation dynamics in a concise period of time. This narrative review will deliver the pathophysiology of deranged hemostasis in ESLD, explore the difficulties of evaluating the coagulopathies in liver disease patients, and examine the use of VET assays and management of coagulopathy using coagulation factors. Methods: A selective literature search with PubMed as the central database was performed with the following.

Machine learning-based prediction of massive perioperative allogeneic blood transfusion in cardiac surgery.

BACKGROUND: Massive perioperative allogeneic blood transfusion, that is, perioperative transfusion of more than 10 units of packed red blood cells (pRBC), is one of the main contributors to perioperative morbidity and mortality in cardiac surgery. Prediction of perioperative blood transfusion might enable preemptive treatment strategies to reduce risk and improve patient outcomes while reducing resource utilisation. We, therefore, investigated the precision of five different machine learning algorithms to predict the occurrence of massive perioperative allogeneic blood transfusion in cardiac surgery at our centre. OBJECTIVE: Is it possible to predict massive perioperative allogeneic blood transfusion using machine learning? DESIGN: Retrospective, observational study. SETTING: Single adult cardiac surgery centre in Austria between 01 January 2010 and 31 December 2019. PATIENTS: Patients undergoing cardiac surgery. MAIN OUTCOME MEASURES: Primary outcome measures were the number of patients receiving at least 10 units pRBC, the area under the curve for the receiver operating characteristics curve, the F1 score, and the negative-predictive (NPV) and positive-predictive values (PPV) of the five machine learning algorithms used to predict massive perioperative allogeneic blood transfusion. RESULTS: A total of 3782 (1124 female:) patients were enrolled and 139 received at least 10 pRBC units. Using all features available at hospital admission, massive perioperative allogeneic blood transfusion could be excluded rather accurately. The best area under the curve was achieved by Random Forests: 0.810 (0.76 to 0.86) with high NPV of 0.99). This was still true using only the eight most important features [area under the curve 0.800 (0.75 to 0.85)]. CONCLUSION: Machine learning models may provide clinical decision support as to which patients to focus on for perioperative preventive treatment in order to preemptively reduce massive perioperative allogeneic blood transfusion by predicting, which patients are not at risk. TRIAL REGISTRATION: Johannes Kepler University Ethics Committee Study Number 1091/2021, Clinicaltrials.gov identifier NCT04856618.

Machine learning-based risk profile classification of patients undergoing elective heart valve surgery.

OBJECTIVES: Machine learning methods potentially provide a highly accurate and detailed assessment of expected individual patient risk before elective cardiac surgery. Correct anticipation of this risk allows for the improved counselling of patients and avoidance of possible complications. We therefore investigated the benefit of modern machine learning methods in personalized risk prediction for patients undergoing elective heart valve surgery. METHODS: We performed a monocentric retrospective study in patients who underwent elective heart valve surgery between 1 January 2008 and 31 December 2014 at our centre. We used random forests, artificial neural networks and support vector machines to predict the 30-day mortality from a subset of 129 available demographic and preoperative parameters. Exclusion criteria were reoperation of the same patient, patients who needed anterograde cerebral perfusion due to aortic arch surgery and patients with grown-up congenital heart disease. Finally, the cohort consisted of 2229 patients with a 30-day mortality of 3.86% (86 of 2229 cases). This trial has been registered at clinicaltrials.gov (NCT03724123). RESULTS: The final random forest model trained on the entire data set provided an out-of-bag area under the receiver operator characteristics curve (AUC) of 0.839, which significantly outperformed the European System for Cardiac Operative Risk Evaluation (EuroSCORE) (AUC = 0.704) and a model trained only on the subset of features EuroSCORE uses (AUC = 0.745). CONCLUSIONS: Advanced machine learning methods can predict outcomes of valve surgery procedures with higher accuracy than established risk scores based on logistic regression on pre-selected parameters. This approach is generalizable to other elective high-risk interventions and allows for training models to the cohorts of specific institutions.

Standards and Best Practice for Acute Normovolemic Hemodilution: Evidence-based Consensus Recommendations.

OBJECTIVE: To develop a standardized approach to the implementation and performance of acute normovolemic hemodilution (ANH) in order to reduce the incidence of bleeding and allogeneic blood transfusion in high-risk surgical bleeding-related cardiac surgery with cardiopulmonary bypass (CPB). DESIGN: A 2-round modified RAND-Delphi consensus process. PARTICIPANTS: Seven physicians from multiple geographic locations and clinical disciplines including anesthesiology and cardiac surgery and 1 cardiac surgery perfusionist participated in the survey. One registered nurse, specializing in Patient Blood Management, participated in the discussion but did not participate in the survey. METHODS: A modified RAND-Delphi method was utilized that integrated evidence review with a face-to-face expert multidisciplinary panel meeting, followed by repeated scoring using a 9-point Likert scale. Consensus was determined as a result from the second round survey, as follows: median rating of 1-3: ANH acceptable; median rating of 7-9: ANH not acceptable; median rating of 4-6: use clinical judgment. RESULTS: Evidentiary review identified 18 key peer-reviewed manuscripts for discussion. Through the consensus-building process, 39 statements including 26 contraindications to ANH and 10 CPB patient variables were assessed. In total, 22 statements were accepted or modified for the second scoring round. CONCLUSIONS: Consensus was reached on 6 conditions in which ANH would or would not be acceptable, showing that development of a standardized approach for the use of ANH in high-risk surgical bleeding and allogeneic blood transfusion is clearly possible. The recommendations developed by this expert panel may help guide the management and inclusion of ANH as an evidence and consensus-based blood conservation modality.

Factor XIII activity in patients requiring surgical re-exploration for bleeding after elective cardiac surgery - A prospective case control study.

PURPOSE: Surgical re-exploration due to postoperative bleeding is associated with increased morbidity and mortality. The aim of our study was to assess a potential association between the level of postoperative FXIII activity and need for re-exploration due to bleeding in patients undergoing cardiothoracic surgery. MATERIALS AND METHODS: In our prospective single center observational cohort study, we enrolled patients who underwent elective cardiothoracic surgery. Patients who required re-exploration (RE group) were matched to patients from the study population (non-RE group). RESULTS: The study included 64 patients, out of a cohort of 678 patients, of whom 32 required surgical re-exploration due to bleeding within the first 24 h. Between patients of the RE and non-RE group, a significantly reduced FXIII activity was observed postoperatively (59.0 vs 71.1; p = .014). Multivariable analysis revealed reduced FXIII activity (p = .048) as a parameter independently associated with surgical re-exploration. Further, reduced FXIII activity (p = .037) and surgical re-exploration (p = .01) were significantly associated with increased 30 day mortality. In multivariable analysis re-exploration was independently associated with increased risk of 30 day mortality (p = .004, HR 9.68). CONCLUSIONS: Reduced postoperative FXIII activity may be associated with the need for surgical re-exploration. Postoperative assessment of FXIII activity should therefore be considered in patients undergoing elective cardiothoracic surgery.

Open Heart Surgery in Jehovah's Witnesses: A Propensity Score Analysis.

BACKGROUND: Jehovah's Witnesses (JW) refuse allogeneic blood transfusions and therefore pose a unique challenge in case of major surgery. This retrospective study reviewed an experience with JW patients who were undergoing open heart surgery. METHODS: By using patient blood management strategies, 35 adult JW patients underwent cardiac surgery at Kepler University Hospital in Linz, Austria between 2008 and 2017. Outcomes were compared with patients who accepted blood transfusions (non-JW patients) by using propensity score matching. RESULTS: There were no significant differences in clinical and operative data between the groups. Twelve JW patients (34.3%) were pretreated with erythropoietin and iron, with a preoperative increase in mean hemoglobin of 2.0 g/dL. On admission, hemoglobin was 14.1 ± 1.1 g/dL in JW patients, compared with 13.2 ± 2.0 g/dL in non-JW patients (P = .022). The hematocrit in JW patients was higher throughout the hospital stay, even though 51.4% of non-JW patients received allogeneic red blood cell transfusions. The perioperative red blood cell loss was significantly lower in JW patients than in non-JW patients (619 ± 420 mL vs 929 ± 520 mL; P = .010). Major complication rates were not different between the groups. The hemoglobin at discharge was 11.5 ± 1.5 g/dL in JW patients compared with 10.3 ± 1.3 g/dL in non-JW patients (P < .001). In-hospital mortality was 2.9% in each group, and long-term survival was comparable. CONCLUSIONS: By implementing patient blood management, open heart surgery in JW patients can be performed with low morbidity and mortality. Preoperative optimization of hemoglobin and minimization of perioperative blood loss are cornerstones in the prevention of blood loss, anemia, and transfusions.

Machine learning based prediction of perioperative blood loss in orthognathic surgery.

The aim of this study was to evaluate, if and with what accuracy perioperative blood loss can be calculated by a machine learning algorithm prior to orthognathic surgery. The investigators implemented a random forest algorithm to predict perioperative blood loss. 1472 patients who underwent orthognathic surgery from 01/2006 to 06/2017 at our institution were screened and 950 patients were included and separated 80%/20% in a training set - utilized to generate the prediction model - and a testing set - utilized to estimate the accuracy of the model. The outcome variable was the correlation between actual perioperative blood loss and predicted perioperative blood loss in the testing set. Other study variables were the difference of actual and predicted perioperative blood loss and important factors influencing perioperative blood loss using random forest feature importance. Descriptive and bivariate statistics were computed and the P value was set at 0.05. There was a statistically significant correlation between actual perioperative blood loss and predicted perioperative blood loss (p < 0.001). The mean difference was 7.4 ml with a standard deviation of 172.3 ml. The results of this study suggest that the application of a machine-learning algorithm allows a prediction of perioperative blood loss prior to orthognathic surgery.

Patient Blood Management for Neonates and Children Undergoing Cardiac Surgery: 2019 NATA Guidelines.

Pediatric cardiac surgery is associated with a substantial risk of bleeding, frequently requiring the administration of allogeneic blood products. Efforts to optimize preoperative hemoglobin, limit blood sampling, improve hemostasis, reduce bleeding, correct coagulopathy, and incorporate blood sparing techniques (including restrictive transfusion practices) are key elements of patient blood management (PBM) programs, and should be applied to the pediatric cardiac surgical population as across other disciplines. Many guidelines for implementation of PBM in adults undergoing cardiac surgery are available, but evidence regarding the implementation of PBM in children is limited to systematic reviews and specific guidelines for the pediatric cardiac population are missing. The objective of the task force from the Network for the Advancement of Patient Blood Management, Haemostasis and Thrombosis (NATA, www.nataonline.com) is to provide evidence-based recommendations regarding anemia management and blood transfusion practices in the perioperative care of neonates and children undergoing cardiac surgery, and to highlight potential areas where additional research is urgently required.

The efficacy of pre-operative preparation with intravenous iron and/or erythropoietin in anaemic patients undergoing orthopaedic surgery: An observational study.

BACKGROUND: Pre-operative anaemia and transfusion are common among patients undergoing elective orthopaedic surgery. Application of 'patient blood management' might be the most effective way to reduce both anaemia and transfusion. Pre-operative administration of iron and/or erythropoietin (EPO) is one of the cornerstones of the first pillar of patient blood management, but in a daily clinical setting, efficacy and long-term safety of this measure have not been analysed thoroughly to date. OBJECTIVE: To investigate the influence of pre-operative preparation (PREP) of patients with iron and/or EPO on peri-operative transfusion needs and long-term survival. DESIGN: Single-centre, retrospective study. SETTING: Anaesthesia department, University hospital. INTERVENTIONS: Pre-operative preparation with iron and/or EPO versus no preparation. METHODS: After approval of our local ethics committee, data of 5518 patients who received total hip or total knee replacement between 2008 and 2014 were included. Patients receiving iron and/or EPO were included in the PREP group, whereas patients without iron and/or EPO were included in the no preparation group. From the full data set, a bias-reduced subset of 662 patients was obtained by means of propensity score-matching to compare peri-operative red blood cell utilisation and long-term survival of patients between groups. RESULTS: Patients in the PREP group needed a lower number of units of red blood cells than patients in the no preparation group (0.2 ±â€Š0.8 vs. 0.5 ±â€Š1.3, P < 0.001), had a lower transfusion rate (12 vs. 24%, P < 0.05) and had a similar haemoglobin concentration (10.7 ±â€Š1.3 vs. 10.6 ±â€Š1.1 g dl, not significant) at discharge. No differences in long-term survival were observed between the two study groups. CONCLUSION: PREP of patients with iron and/or EPO in orthopaedic patients can be considered highly effective in terms of transfusion reduction, without influencing long-term survival.

Anemia tolerance during normo-, hypo-, and hypervolemia.

BACKGROUND: Restrictive intraoperative fluid management has been demonstrated to improve outcome of visceral and lung surgery in several studies. However, subsequent hypovolemia (HOV) may be accompanied by a decrease of anemia tolerance, resulting in increased transfusion needs. We therefore investigated the effect of volume status on anemia tolerance. STUDY DESIGN AND METHODS: Eighteen domestic pigs of either sex (mean weight, 23.5 ± 4.8 kg) were anesthetized, ventilated, and randomized into three experimental groups: normovolemia (no intervention), HOV (blood loss of 40% of blood volume), and hypervolemia (HEV; volume infusion of 40% of blood volume). The animals were then hemodiluted until their individual critical hemoglobin concentrations (Hbcrit ) were reached by the exchange of whole blood for hydroxyethyl starch (HES; 130:0.4). Subsequently, organ-specific hypoxia was assessed using pimonidazole tissue staining in relevant organs. Hemodynamic and metabolic variables were also investigated. RESULTS: Despite significant differences in exchangeable blood volume, Hbcrit was the same in all groups (2.3 g/dL, NS). During HOV, tissue hypoxia was aggravated in the myocardium, brain, and kidneys, whereas tissue oxygenation of the liver and intestine was not influenced by volume status. HEV increased tissue hypoxia in the lungs, but did not impact tissue oxygenation of other organs. CONCLUSIONS: The combination of hemorrhagic HOV with subsequent anemia leads to accentuated tissue hypoxia, revealed by a significant increase in pimonidazole binding at Hbcrit , in heart, lungs, brain, and kidney. The lungs were the only organ that showed increased tissue hypoxia after pretreatment of HES infusion and subsequent anemia by normovolemic hemodilution.

Blood transfusion and coagulation management.

Despite impressive progress in surgical technique, aortic surgery is still associated with relatively high morbidity and mortality. One of the most important contributors to this phenomenon is the triad of bleeding, anemia, and transfusion. All three factors are known to influence the outcome of aortic surgery to a great extent. However, over the last few years a multidisciplinary, multimodal concept has been established, which enables the physician to avoid bleeding, anemia, and transfusion as much as possible. The concept of "patient blood management" combines several established measures with the potential to improve perioperative outcome. This chapter describes these measures with regard to aortic surgery and assesses their respective efficacy.

Reduction of transfusion requirements in pediatric craniosynostosis surgery by a new local hemostatic agent.

BACKGROUND AND OBJECTIVES: Craniosynostosis surgery is often associated with severe perioperative bleeding especially due to venae emissariae, resulting in large transfusion amounts of packed red blood cells (PRBCs). Blood loss from venae emissariae is usually reduced by the usage of bone wax. SeraSeal is a new hemostatic agent which might help to reduce transfusion amounts if used additionally to bone wax. MATERIALS AND METHODS: This study was designed with a retrospective control group (23 children), treated only with bone wax and a consecutive prospective verum group (12 children) treated additionally with SeraSeal. All children solely suffered from non-syndromic craniosynostosis, and were all treated by the same surgeons. Primary outcome variable was the volume of PRBC transfused during surgery. RESULTS: The numbers of PRBC transfusion was reduced significantly during the intraoperative period in the SeraSeal group (-44.5%, p < 0.05) and also during the combination of the postoperative and intraoperative period (-59.3%, p < 0.05). CONCLUSION: Our analysis suggests that SeraSeal has a strong potential to reduce transfusion requirements in pediatric craniosynostosis surgery. However, we acknowledge that due to small numbers our trial can only be seen as hypothesis generating pilot study. We suggest that the effect of SeraSeal should be assessed prospectively in other studies.

Predicting treatment process steps from events.

MOTIVATION: The primary economy-driven documentation of patient-specific information in clinical information systems leads to drawbacks in the use of these systems in daily clinical routine. Missing meta-data regarding underlying clinical workflows within the stored information is crucial for intelligent support systems. Unfortunately, there is still a lack of primary clinical needs-driven electronic patient documentation. Hence, physicians and surgeons must search hundreds of documents to find necessary patient data rather than accessing relevant information directly from the current process step. In this work, a completely new approach has been developed to enrich the existing information in clinical information systems with additional meta-data, such as the actual treatment phase from which the information entity originates. METHODS: Stochastic models based on Hidden Markov Models (HMMs) are used to create a mathematical representation of the underlying clinical workflow. These models are created from real-world anonymized patient data and are tailored to therapy processes for patients with head and neck cancer. Additionally, two methodologies to extend the models to improve the workflow recognition rates are presented in this work. RESULTS: A leave-one-out cross validation study was performed and achieved promising recognition rates of up to 90% with a standard deviation of 6.4%. CONCLUSIONS: The method presented in this paper demonstrates the feasibility of predicting clinical workflow steps from patient-specific information as the basis for clinical workflow support, as well as for the analysis and improvement of clinical pathways.

Use of lidocaine in endotracheal intubation. Blood and urine concentrations in patients and deceased after unsuccessful resuscitation.

In toxicological analysis of postmortem samples the local anesthetic lidocaine is often identified. In most cases, lidocaine levels result from its use as aid in endotracheal intubation. The range of the drug's concentration in blood and urine was studied under controlled conditions from a cohort of cardiac surgery patients (n=35). Plasma concentrations 1 h after exposure to lidocaine in the range of the recommended 81 mg coating the endotracheal tube were less than 0.2 mg/l, its metabolite monoethylglycinxylidide (MEGX) less than 0.05 mg/l (median ratio 0.18, range 0.03-1.23). Also the concentrations of lidocaine and MEGX in urine samples were low (less than 1.2 and 0.1 mg/l, respectively) with MEGX/lidocaine ratios of 0.11 (median, range up to 1.2). These data were compared with results obtained by analyzing postmortem blood and urine samples of 18 deceased with a documented cardiopulmonary resuscitation attempt prior to death. Blood concentrations were in the same range (lidocaine median 0.07, range 0.02-1.07 mg/l; MEGX median 0.01, range <0.001-0.044 mg/l); besides low lidocaine concentrations in urine. MEGX was detected only in 2 out of 9 urine samples. The results of the present study confirm that lidocaine is absorbed in the trachea from the endotracheal tube coated with lidocaine containing gel. Postmortem quantitative results can be explained on the basis of the data obtained in the controlled study.

Design and evaluation of a multimedia electronic patient record "oncoflow" with clinical workflow assistance for head and neck tumor therapy.

OBJECTIVES: The management of patient-specific information is a challenging task for surgeons and physicians because existing clinical information systems are insufficiently integrated into daily clinical routine and contained information entities are distributed across different proprietary databases. Thus, existing information is hardly usable for further electronic processing, workflow support or clinical studies. METHODS: A Web-based clinical information system has been developed that automatically imports patient-specific information from different information systems. The system is tailored to the existing workflow for the treatment of patients with head and neck cancer. In this paper, the clinical assistance functions and a quantitative as well as a qualitative system evaluation are presented. RESULTS: The information system has been deployed at a clinical site and is in use in daily clinical routine. Two evaluation studies show that the information integration, the structured information presentation in the Web browser and the assistance functions improve the physician's workflow. The studies also show that the usage of the new information system does not impair the time physicians need for a process step compared with the usage of the existing information system. CONCLUSIONS: Information integration is crucial for efficient workflow support in the clinic. The central access to information within a modern and structured user interface saves valuable time for the physician. The comprehensive database allows an instant usage of the existing information clinical workflow support or the conduction of trial studies.