[German "Triage Act"-Regulation with fatal consequences]

With the coming into force of § 5c of the Infection Protection Act (IfSG), the so-called Triage Act, on 14 December 2022, a protracted discussion has come to a provisional conclusion, the result of which physicians and social associations but also lawyers and ethicists are equally dissatisfied. The explicit exclusion of the discontinuation of treatment that has already begun in favor of new patients with better chances of success (so-called tertiary or ex-post triage) prevents allocation decisions with the aim of enabling as many patients as possible to beneficially participate in medical care under crisis conditions. The result of the new regulation is de facto a first come first served allocation, which is associated with the highest mortality even among individuals with limitations or disabilities and was rejected by a large margin as unfair in a population survey. Mandating allocation decisions based on the likelihood of success but which are not permitted to be consistently implemented and prohibiting, for example the use of age and frailty as prioritization criteria, although both factors most strongly determine the short-term probability of survival according to evident data, shows the contradictory and dogmatic nature of the regulation. The only remaining possibility is the consistent termination of treatment that is no longer indicated or desired by the patient, regardless of the current resource situation; however, if a different decision is made in a crisis situation than in a situation without a lack of resources, this practice would not be justified and would be punishable. Accordingly, the highest efforts must be set on legally compliant documentation, especially in the stage of decompensated crisis care in a region. The goal of enabling as many patients as possible to beneficially participate in medical care under crisis conditions is in any case thwarted by the new German Triage Act.

[Bed capacity management in times of the COVID-19 pandemic : A simulation-based prognosis of normal and intensive care beds using the descriptive data of the University Hospital Augsburg]

BACKGROUND

Following the regional outbreak in China, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread all over the world, presenting the healthcare systems with huge challenges worldwide. In Germany the coronavirus diseases 2019 (COVID-19) pandemic has resulted in a slowly growing demand for health care with a sudden occurrence of regional hotspots. This leads to an unpredictable situation for many hospitals, leaving the question of how many bed resources are needed to cope with the surge of COVID-19 patients.

OBJECTIVE

In this study we created a simulation-based prognostic tool that provides the management of the University Hospital of Augsburg and the civil protection services with the necessary information to plan and guide the disaster response to the ongoing pandemic. Especially the number of beds needed on isolation wards and intensive care units (ICU) are the biggest concerns. The focus should lie not only on the confirmed cases as the patients with suspected COVID-19 are in need of the same resources.

MATERIAL AND METHODS

For the input we used the latest information provided by governmental institutions about the spreading of the disease, with a special focus on the growth rate of the cumulative number of cases. Due to the dynamics of the current situation, these data can be highly variable. To minimize the influence of this variance, we designed distribution functions for the parameters growth rate, length of stay in hospital and the proportion of infected people who need to be hospitalized in our area of responsibility. Using this input, we started a Monte Carlo simulation with 10,000 runs to predict the range of the number of hospital beds needed within the coming days and compared it with the available resources.

RESULTS

Since 2 February 2020 a total of 306 patients were treated with suspected or confirmed COVID-19 at this university hospital. Of these 84 needed treatment on the ICU. With the help of several simulation-based forecasts, the required ICU and normal bed capacity at Augsburg University Hospital and the Augsburg ambulance service in the period from 28 March 2020 to 8 June 2020 could be predicted with a high degree of reliability. Simulations that were run before the impact of the restrictions in daily life showed that we would have run out of ICU bed capacity within approximately 1 month.

CONCLUSION

Our simulation-based prognosis of the health care capacities needed helps the management of the hospital and the civil protection service to make reasonable decisions and adapt the disaster response to the realistic needs. At the same time the forecasts create the possibility to plan the strategic response days and weeks in advance. The tool presented in this study is, as far as we know, the only one accounting not only for confirmed COVID-19 cases but also for suspected COVID-19 patients. Additionally, the few input parameters used are easy to access and can be easily adapted to other healthcare systems.

[Risk management in anesthesia and critical care medicine]

Throughout its history, anesthesia and critical care medicine has experienced vast improvements to increase patient safety. Consequently, anesthesia has never been performed on such a high level as it is being performed today. As a result, we do not always fully perceive the risks involved in our daily activity. A survey performed in Swiss hospitals identified a total of 169 hot spots which endanger patient safety. It turned out that there is a complex variety of possible errors that can only be tackled through consistent implementation of a safety culture. The key elements to reduce complications are continuing staff education, algorithms and standard operating procedures (SOP), working according to the principles of crisis resource management (CRM) and last but not least the continuous work-up of mistakes identified by critical incident reporting systems.

[Risk management in anesthesia and critical care medicine]

Throughout its history, anesthesia and critical care medicine has experienced vast improvements to increase patient safety. Consequently, anesthesia has never been performed on such a high level as it is being performed today. As a result, we do not always fully perceive the risks involved in our daily activity. A survey performed in Swiss hospitals identified a total of 169 hot spots which endanger patient safety. It turned out that there is a complex variety of possible errors that can only be tackled through consistent implementation of a safety culture. The key elements to reduce complications are continuing staff education, algorithms and standard operating procedures (SOP), working according to the principles of crisis resource management (CRM) and last but not least the continuous work-up of mistakes identified by critical incident reporting systems.

[Diagnostic investigation in emergency medicine: Why case history is crucial]

We present the preclinical case of a patient reporting chest pain. Pain impeded physical examination. Reviewing the patient's detailed medical history after analgesia revealed a connection between the reported pain and vomiting. This led to a suspicion of organ perforation. Thus, the patient was admitted to a surgical emergency room (ER) and Boerhaave's Syndrome was diagnosed. After deterioration in the ER, cardiopulmonal reanimation (CPR), and successful surgical treatment, the patient was transferred to the intensive care unit (ICU) seven hours after first contact.

[Management of anesthesia in endovascular interventions]

Cardiovascular diseases are one of the leading causes of morbidity and mortality in Germany. In these patients, the high-risk profile necessitates an interdisciplinary and multimodal approach to treatment. Endovascular interventions and vascular surgery have become established as an important element of this strategy in the past; however, the different anatomical localizations of pathological vascular alterations make it necessary to use a wide spectrum of procedural options and methods; therefore, the requirements for management of anesthesia are variable and necessitate a differentiated approach. Endovascular procedures can be carried out with the patient under general or regional anesthesia (RA); however, in the currently available literature there is no evidence for an advantage of RA over general anesthesia regarding morbidity and mortality, although a reduction in pulmonary complications could be found for some endovascular interventions. Epidural and spinal RA procedures should be carefully considered with respect to the risk-benefit ratio and consideration of the recent guidelines on anesthesia against the background of the current study situation and the regular use of therapy with anticoagulants. The following article elucidates the specific characteristics of anesthesia management as exemplified by some selected endovascular interventions.

IgM-enriched solution BT086 improves host defense capacity and energy store preservation in a rabbit model of endotoxemia

Introduction

The therapeutic value of intravenous immunoglobulin (IVIG) as an adjuvant therapy in sepsis remains debatable. We hypothesized that intravenous administration of BT086, a predominantly IgM IVIG solution, would improve host defense in an established rabbit model of endotoxemia and systemic sepsis.

Methods

New Zealand white rabbits were randomized into the following four groups: (1) the negative control group without lipopolysaccharide (LPS, control), (2) the positive control group with LPS infusion (LPS group), (3) the albumin‐treated LPS group (ALB+LPS group), and (4) the BT086‐treated LPS group (BT086 + LPS group). A standardized amount of E. coli was intravenously injected into all of the animals. The vital parameters, the concentration of E. coli in the blood and other organs, the residual granulocyte phagocytosis activity, and the levels of the inflammatory mediators were measured. Histological changes in the lung and liver tissue were examined following autopsy.

Results

The elimination of E. coli from the bloodstream was expedited in the BT086‐treated group compared with the LPS‐ and albumin‐treated groups. The BT086 + LPS group exhibited higher phagocytic activity of polymorphonuclear neutrophils (PMNs) than the control and ALB+LPS groups. The liver energy stores were higher in the BT086 + LPS group than in the other groups.

Conclusion

Our data suggest that the IgM‐enriched IVIG has the potential to improve host defense in a rabbit model of endotoxemia. Studies using different animal models and dosages are necessary to further explore the potential benefits of IgM‐enriched IVIG solutions.

[Obstructive shock]

An acute obstruction of blood flow in central vessels of the systemic or pulmonary circulation causes the clinical symptoms of shock accompanied by disturbances of consciousness, centralization, oliguria, hypotension and tachycardia. In the case of an acute pulmonary embolism an intravascular occlusion results in an acute increase of the right ventricular afterload. In the case of a tension pneumothorax, an obstruction of the blood vessels supplying the heart is caused by an increase in extravascular pressure. From a hemodynamic viewpoint circulatory shock caused by obstruction is closely followed by cardiac deterioration; however, etiological and therapeutic options necessitate demarcation of cardiac from non-cardiac obstructive causes. The high dynamics of this potentially life-threatening condition is a hallmark of all types of obstructive shock. This requires an expeditious and purposeful diagnosis and a rapid and well-aimed therapy.

Cafedrine/theodrenaline in anaesthesia: influencing factors in restoring arterial blood pressure

Background

Hypotensive states that require fast stabilisation of blood pressure can occur during anaesthesia. In 1963, the 20:1 mixture of cafedrine/theodrenaline (Akrinor^®) was introduced in Germany for use in anaesthesia and emergency medicine in the first-line management of hypotensive states. Though on the market for many years, few pharmacodynamic data are available on this combination net beta-mimetic agent.

Aim

This study aimed to examine the drug combination in real-life clinical practice and recorded time to 10 % mean arterial blood pressure (MAP) increase and heart rate. Furthermore, potential factors that influence drug effectiveness under anaesthesia were assessed.

Methods

Data were collected within a standardised anaesthesia protocol. A total of 353 consecutive patients (female/male = 149/204) who received cafedrine/theodrenaline after a drop in MAP ≥ 5 % were included in the study. The time to 10 % increase in MAP, dosage of cafedrine/theodrenaline, volume loading, blood pressure and heart rate were monitored over time.

Results

Patients were a mean (standard deviation) of 64.4 ± 15.1 years old with a baseline MAP of 82 ± 14 mmHg, which dropped to a mean of 63 ± 10 mmHg during anaesthesia without gender differences. Cafedrine/theodrenaline (1.27 ± 1.0 mg/kg; 64 ± 50 µg/kg) significantly increased MAP (p < 0.001) by 11 ± 16 mmHg within 5 min, reaching peak values within 17.4 ± 9.0 min. Heart rate was not affected in a clinically significant manner. Cafedrine/theodrenaline induced a 10 % MAP increase after 7.2 ± 4.6 min (women) and after 8.6 ± 6.3 min (men) (p = 0.018). Independent of gender, the dose of cafedrine/theodrenaline required to achieve the observed MAP increase of 14 ± 16 mmHg at 15 min was significantly different in patients with heart failure [1.78 ± 1.67 mg/kg (cafedrine)/89.0 ± 83.5 µg/kg (theodrenaline)] compared with healthy patients [1.16 ± 0.77 mg/kg (cafedrine)/58.0 ± 38.5 µg/kg (theodrenaline)] (p = 0.005). Concomitant medication with beta-blocking agents significantly prolonged the time to 10 % MAP increase [9.0 ± 7.0 vs. 7.3 ± 4.3 min (p = 0.008)].

Conclusion

Cafedrine/theodrenaline quickly restores MAP during anaesthesia. Female gender is associated with higher effectiveness, while heart failure and beta-blocker administration lower the anti-hypotonic effect. Prospective studies in defined patient populations are warranted to further characterise the effect of cafedrine/theodrenaline.

Effects of awareness and nociception on heart rate variability during general anaesthesia

During anaesthesia awareness and nociception are serious complications that may further lead to haemodynamic instability. Specific monitoring of depth of hypnosis and depth of analgesia based on heart rate variability (HRV) analysis is eligible to improve patient safety and reduce efforts in post-operative care. Consequently, in this analysis we assess the applicability of HRV parameters during surgical interventions with standardized intravenous propofol-remifentanil-anaesthesia. Peri-operative electrocardiograms were recorded from cardiovascular stable patients (ASA Score I/II, N = 32, age: 36.4 ± 11.23 a, BMI: 25.2 ± 3.16) scheduled for trauma and dentofacial surgery. HRV time- and frequency-domain parameters, measures of complexity and nonlinear dynamics were compared by analysing longitudinally distributed 300 s intervals preceding/following induction of anaesthesia (BL-I1), intubation (I1-I2) and extubation (E1-E2). Mean value (meanNN) and standard deviation (sdNN) of the heart rate are influenced in BL-I1 (p < 0.001), I1-I2 (p < 0.05) and E1-E2 (p < 0.001). The number of forbidden words of symbolic dynamics changes significantly for BL-I1 (p < 0.001) and not for I1-I2 and E1-E2 (p > 0.05). Probability of low-variability POLVAR10 is significantly altered in all comparisons (BL-I1: Δ = 0.032, p < 0.01, I1-I2: Δ = 0.12, p < 0.05, E1-E2: Δ = 0.169, p < 0.01) but especially during nociception. While standard time-domain parameters lacked selectivity, parameters of symbolic dynamics appear to be specifically influenced by changes in depth of hypnosis and nociception, respectively. However, the lack of steady-state ventilation/breathing in this study needs to be considered in future research. To be used for clinical anaesthesia monitoring our results have to be prospectively validated in clinical studies.

[Cardioprotection]

The demographic change is associated with an increasing number of elderly patients with serious comorbidities. The prevalence of coronary heart disease in particular increases with age and raises the risk of perioperative myocardial ischemia. In the last few years various interventions have been evaluated to lower the perioperative risk for serious cardiovascular events. This includes cardioprotective medical interventions, for example with β-receptor blockers and statins. Current guidelines recommend that patients who are on β-receptor blockers or statins for chronic treatment of cardiovascular diseases should continue this medication throughout the perioperative period. Myocardial conditioning has been assessed to be effective under numerous experimental conditions and clinical trials have also provided evidence for myocardial protection by conditioning. Besides ischemic and anesthetic-induced preconditioning the noninvasive technique of remote preconditioning offers interesting possibilities, especially for patients with serious comorbidities; however, large scale randomized clinical multicentre trials are still needed. Regarding cardioprotective effectiveness, the clinical data for regional anesthesia are very heterogeneous; nevertheless regional anesthesia is very effective in postoperative pain therapy. Therefore regional anesthesia should be used as a part of multimodal therapy concepts to lower the risk of perioperative cardiovascular events.

[Perioperative visual loss after nonocular surgery]

Perioperative visual loss (POVL) after nonocular surgery is a rare but unexpected event and represents a devastating complication. It is most often associated with cardiac, spinal as well as head and neck surgery. The etiology of POVL remains incompletely understood. Any portion of the visual system may be involved, from the cornea to the occipital lobe. The most common site of permanent injury is, however, the optic nerve itself and ischemia is the most often presumed mechanism. Multiple factors have been proposed as risk factors for POVL, including long duration in the prone position, decreased ocular perfusion pressure, excessive blood loss and anemia, hypotension, hypoxia, excessive fluid replacement, elevated venous pressure, head positioning and a patient-specific vascular susceptibility which may be anatomic or physiologic. However, the risk factors for any given patient or procedure may vary. The underlying specific pathogenesis of these neuro-ophthalmic complications remains unknown and physicians should be alert to the potential for loss of vision in the postoperative period. This review updates readers on the incidence, suspected risk factors, diagnosis and treatment of POVL in the setting of nonocular surgery.

Impact of cafedrine/theodrenaline (Akrinor® ) on therapy of maternal hypotension during spinal anesthesia for Cesarean delivery: a retrospective study

AIM

Maternal hypotension is the most frequent complication in spinal anesthesia for Cesarean delivery. Malperfusion of the foetus and nausea and vomiting of the mother are hallmarks of maternal hypotension. In this retrospective data analysis and anesthesia protocols we have investigated to explore the effects of therapeutic interventions for hypotension with cafedrine/theodrenaline (Akrinor® ) during spinal anesthesia for elective Cesarean section.

METHODS

In a retrospective study anesthesia charts of 173 parturients undergoing spinal anesthesia for Cesarean delivery with 10mg hyperbaric bupivacaine + 5 µg sufentanil were reviewed for 30 min after onset of hypotension with respect to blood pressure, heart rate, respiration rate, as well as APGAR scores and umbilical arterial pH. Maternal data were compared to baseline values recorded and documented immediately before placing the spinal anesthesia in the operating room. The cohort was divided into two groups according to their hemodynamic response to spinal anesthesia: 117 parturients had a drop of systolic blood pressure to <120 mmHg or <80% of baseline blood pressure and were therefore treated with Akrinor® (cafedrine/theodrenaline; treatment group); 56 patients remained within the specified limits (non-treatment group). Maternal cardiovascular parameters and newborn outcome between the groups were compared.

RESULTS

Both groups were comparable with regard to baseline characteristics. In the treatment group one minute after the first application of cafedrine (43 mg)/theodrenaline (2.2 mg) mean systolic blood pressure raised from 108.6 mmHg to 117.2 mmHg (P=0.0004), mean of maximal changes of systolic blood pressure after the first application of Akrinor® was 21.3 mmHg. Blood pressure levels of the non-treatment group were regained in the treatment group 8 min after hypotension onset and remained at that level until the end of 30 min observation. No clinically relevant changes of heart rate were detectable. While mean APGAR score one minute post partum was significantly higher in the treatment group (8.9±1.2 vs. 8.4±1.1 P=0.043), mean umbilical arterial cord pH was 7.3±0.1 and APGAR scores 5 and 10 minutes postpartum did not differ significantly.

CONCLUSION

The results of this study confirm a rapid and sustained increase in blood pressure after application of Akrinor® for treatment of sympathicolysis induced hypotension. No negative impact of Akrinor® on umbilical arterial cord pH and APGAR scores was observed.

S3 guidelines for intensive care in cardiac surgery patients: hemodynamic monitoring and cardiocirculary system

Hemodynamic monitoring and adequate volume-therapy, as well as the treatment with positive inotropic drugs and vasopressors are the basic principles of the postoperative intensive care treatment of patient after cardiothoracic surgery. The goal of these S3 guidelines is to evaluate the recommendations in regard to evidence based medicine and to define therapy goals for monitoring and therapy. In context with the clinical situation the evaluation of the different hemodynamic parameters allows the development of a therapeutic concept and the definition of goal criteria to evaluate the effect of treatment. Up to now there are only guidelines for subareas of postoperative treatment of cardiothoracic surgical patients, like the use of a pulmonary artery catheter or the transesophageal echocardiography. The German Society for Thoracic and Cardiovascular Surgery (Deutsche Gesellschaft für Thorax-, Herz- und Gefässchirurgie, DGTHG) and the German Society for Anaesthesiology and Intensive Care Medicine (Deutsche Gesellschaft für Anästhesiologie und lntensivmedizin, DGAI) made an approach to ensure and improve the quality of the postoperative intensive care medicine after cardiothoracic surgery by the development of S3 consensus-based treatment guidelines. Goal of this guideline is to assess the available monitoring methods with regard to indication, procedures, predication, limits, contraindications and risks for use. The differentiated therapy of volume-replacement, positive inotropic support and vasoactive drugs, the therapy with vasodilatators, inodilatators and calcium sensitizers and the use of intra-aortic balloon pumps will also be addressed. The guideline has been developed following the recommendations for the development of guidelines by the Association of the Scientific Medical Societies in Germany (AWMF). The presented key messages of the guidelines were approved after two consensus meetings under the moderation of the Association of the Scientific Medical Societies in Germany (AWMF).

Lipid emulsions - Guidelines on Parenteral Nutrition, Chapter 6

The infusion of lipid emulsions allows a high energy supply, facilitates the prevention of high glucose infusion rates and is indispensable for the supply with essential fatty acids. The administration of lipid emulsions is recommended within ≤7 days after starting PN (parenteral nutrition) to avoid deficiency of essential fatty acids. Low-fat PN with a high glucose intake increases the risk of hyperglycaemia. In parenterally fed patients with a tendency to hyperglycaemia, an increase in the lipid-glucose ratio should be considered. In critically ill patients the glucose infusion should not exceed 50% of energy intake. The use of lipid emulsions with a low phospholipid/triglyceride ratio is recommended and should be provided with the usual PN to prevent depletion of essential fatty acids, lower the risk of hyperglycaemia, and prevent hepatic steatosis. Biologically active vitamin E (α-tocopherol) should continuously be administered along with lipid emulsions to reduce lipid peroxidation. Parenteral lipids should provide about 25–40% of the parenteral non-protein energy supply. In certain situations (i.e. critically ill, respiratory insufficiency) a lipid intake of up to 50 or 60% of non-protein energy may be reasonable. The recommended daily dose for parenteral lipids in adults is 0.7–1.3 g triglycerides/kg body weight. Serum triglyceride concentrations should be monitored regularly with dosage reduction at levels >400 mg/dl (>4.6 mmol/l) and interruption of lipid infusion at levels >1000 mg/dl (>11.4 mmol/l). There is little evidence at this time that the choice of different available lipid emulsions affects clinical endpoints.

The effects of electromyographic activity on the accuracy of the Narcotrend monitor compared with the Bispectral Index during combined anaesthesia

The Narcotrend is a monitor system for the assessment of depth of anaesthesia. The objective of this trial was to investigate the susceptibility of the Narcotrend to electromyographic (EMG) activity when compared with the Bispectral Index (BIS). We enrolled 33 patients undergoing major urological procedures under combined anaesthesia (thoracic epidural analgesia and general anaesthesia). Anaesthetic depth was assessed simultaneously by the BIS XP and Narcotrend. The intended anaesthetic depth ranged between 40 and 55 in the BIS and between D2 and D0 in the Narcotrend. BIS, but not Narcotrend, values correlated significantly (p < 0.0001) with EMG. BIS values between 70 and 80 occurred intermittently above an EMG activity of 35 dB, whereas the Narcotrend and the clinical signs remained unchanged during the period of elevated BIS values. None of the patients reported intra-operative awareness. Increased electromyographic activity does not affect Narcotrend values. Under combined anaesthesia, the Narcotrend monitor is more reliable when compared with the BIS regarding susceptibility to increased EMG activity.

SPATIAL PULMONARY FLOW DISTRIBUTION IN RABBIT ISOLATED LUNGS IS A POOR REPRESENTATION OF THE SITUATION IN VIVO*

1. Isolated lung preparations are established to investigate effects on pulmonary vascular tone and spatial pulmonary flow (Q (rel)) distribution. In the present study, we hypothesized that Q (rel) distribution in isolated lungs is only poorly correlated with the in vivo situation. 2. Fourteen rabbits were anaesthetized and mechanically ventilated with room air. Animals were held in an upright position for 15 min and Q (rel) was assessed using fluorescent microspheres (Q (rel-in vivo)). A second injection of microspheres was made after isolation of the lungs (Q (rel-ex vivo)). Lungs were dried, cut into 1 cm(3) cubes and spatial Q (rel) distributions were analysed. 3. The mean correlation of Q (rel-in vivo) and Q (rel-ex vivo) was 0.592 +/- 0.188 (95% confidence interval 0.493-0.690). The Q (rel) was redistributed to more ventral (the mean slope of Q (rel) vs the dorsal-ventral axis changed from -0.289 +/- 0.227 to -0.147 +/- 0.114; P = 0.03), cranial (mean slope of Q (rel) vs the caudal-cranial axis changed from -0.386 +/- 0.193 to -0.176 +/- 0.142; P < 0.001) and central (mean slope of Q (rel) vs the hilus-peripheral axis changed from 0.436 +/- 0.133 to -0.236 +/- 0.159; P = 0.003) lung areas. 4. The results obtained from studies investigating Q (rel) distributions in isolated lung models must be interpreted cautiously because the isolated lung set-up significantly affects the spatial distribution of pulmonary flow.

Insulin effects on myocardial function and bioenergetics in L-bupivacaine toxicity in the isolated rat heart

BACKGROUND AND OBJECTIVES

A positive effect of insulin-glucose-potassium infusion in severe bupivacaine-induced cardiovascular collapse has been described in vivo. It has been speculated that an antagonistic influence of insulin on sodium channel inhibition, transient outward potassium current, calcium-dependent adenosine triphosphatase or even improved myocardial energetics may be responsible for this effect. Using an isolated heart model, we therefore sought to further elucidate insulin effects in l-bupivacaine-induced myocardial depression.

METHODS

An isolated rat heart constant-pressure perfused, non-recirculating Langendorff preparation was used. Hearts were exposed to l-bupivacaine 5 microg mL(-1) and insulin 10 mIU mL(-1). Heart rate, systolic pressure, the first derivative of left ventricular pressure (+dP/dt), coronary flow, double product, PR and QRS intervals were recorded. Hearts were freeze-clamped and high-performance liquid chromatography measurement of the total adenine nucleotide pool was performed.

RESULTS

l-Bupivacaine led to a significant decrease in heart rate, +dP/dt, systolic pressure, coronary flow and double product, and to an increase in PR and QRS. Insulin exerted a positive inotropic effect, significantly augmenting +dP/dt and systolic pressure in both l-bupivacaine-treated and control hearts. Heart rate, coronary flow, total adenine nucleotides, PR and QRS were not significantly changed by the insulin intervention.

CONCLUSION

Insulin did not have a significant effect on total adenine nucleotides in controls and in l-bupivacaine-treated hearts. However, it does exert a positive inotropic action in bupivacaine-induced myocardial depression. We conclude that the positive effect of insulin application lies in positive inotropic action and not in changes in total adenine nucleotides.

Adenosine A1 and A2 receptor agonists reduce endotoxin-induced cellular energy depletion and oedema formation in the lung

BACKGROUND AND OBJECTIVE

Tissue depletion of adenosine during endotoxaemia has previously been described in the lung. Therapeutic approaches to prevent adenosine depletion and the role of A1 and A2 receptor agonists, however, have not been investigated until now.

METHODS

In isolated and ventilated rabbit lungs, it was tested whether pretreatment with adenosine A1 agonist 2-chloro-N6-cyclopentyladenosine (CCPA; 10(-7) mol, n = 6) or A2 receptor agonist 5'-(N-cyclopropyl)-carboxyamido adenosine (CPCA; 10(-7) mol, n = 6) prior to injection of lipopolysaccharide (LPS) (500 pg mL-1) influenced pulmonary artery pressure (PAP), pulmonary energy content and oedema formation as compared with controls, solely infused with LPS (n = 6). Release rates of adenosine and uric acid were determined by high-performance liquid chromatography. Pulmonary tissue concentrations of high-energy phosphates were measured and the adenine nucleotide pool, adenosine 5'-triphosphate (ATP)/adenosine 5'-diphosphate (ADP) ratio and adenylate energy charge of the pulmonary tissue were calculated.

RESULTS

Administration of LPS induced increases in PAP within 2 h up to 20.8 +/- 2.9 mmHg (P < 0.01). While pretreatment with the A1 agonist merely decelerated pressure increase (13.8 +/- 1.1 mmHg, P < 0.05), the A2 agonist completely suppressed the pulmonary pressure reaction (9.6 +/- 1.0 mmHg, P < 0.01). Emergence of lung oedema after exclusive injection of LPS up to 12.0 +/- 2.9 g was absent after A1 (0.6 +/- 0.5 g) and A2 (-0.3 +/- 0.2 g) agonists. These observations were paralleled by increased adenosine release rates compared with LPS controls (P < 0.05). Moreover, tissue concentrations of ADP, ATP, guanosine 5'-diphosphate, guanosine 5'-triphosphate, nicotinamide-adenine-dinucleotide and creatine phosphate were significantly reduced after LPS. Consequently, the calculated tissue adenine nucleotide pool and the adenylate energy charge increased after adenosine receptor stimulation (P = 0.001).

CONCLUSIONS

Adenosine A1- and A2-receptor agonists reduced LPS-induced vasoconstriction and oedema formation by maintenance of tissue energy content. Thus, adenosine receptor stimulation, in particular of the A2 receptor, might be beneficial during acute lung injury.

Betriebswirtschaftliche Auswirkungen der thorakalen Epiduralanästhesie bei urologischen Operationen

INTRODUCTION

Using the surgical procedure OPS 5-604.0 (radical retropubic prostatectomy) as an example, our study identifies revenue-relevant patient characteristics and describes the impact of the perioperative application of thoracic epidural analgesia (TEA).

METHODS

Factors affecting duration of stay were determined in 460 patients undergoing OPS 5-604.0 in the year 2001 and 2002 using multifactorial regression analysis. Preoperative parameters served as factors for matched-pair analysis of the effects of TEA.

RESULTS

Characteristics significantly affecting length of postoperative hospital stay were ASA status, age, preoperative haemoglobin concentration, postoperative tachycardia, number of transfused packed red cells, wound infection and surgical revision. Based on identical matching criteria 27 pairs (with/without TEA) could be formed. While the induction time in the TEA group was 8+/-18 min longer (p=0.04), emergence was briefer by 3+/-9 min (p=0.045). Neither anaesthesia presence time nor anaesthesia costs or total costs of surgery differed significantly between the pairs. However, duration of epidural postoperative pain therapy was longer with TEA but in contrast, the postoperative length of hospital stay after TEA was reduced. Assuming a continuous demand for OPS 5-604.0 procedures, TEA enables 32 more procedures to be carried out per year with an increased yield on turnover of 2.7%.

CONCLUSION

At first sight combined anaesthesia procedures require more human resources and material, however, as a result of shortened hospital stay and optimized pain therapy patient satisfaction increases and a substantial potential for increased revenue is gained.

Rigor mortis- ein sicheres Todeszeichen?

In the past years an ongoing controversial debate exists in Germany, regarding quality of the coroner's inquest and declaration of death by physicians. We report the case of a 90-year old female, who was found after an unknown time following a suicide attempt with benzodiazepine. The examination of the patient showed livores (mortis?) on the left forearm and left lower leg. Moreover, rigor (mortis?) of the left arm was apparent which prevented arm flexion and extension. The hypothermic patient with insufficient respiration was intubated and mechanically ventilated. Chest compressions were not performed, because central pulses were (hardly) palpable and a sinus bradycardia 45/min (AV-block 2 degrees and sole premature ventricular complexes) was present. After placement of an intravenous line (17 G, external jugular vein) the hemodynamic situation was stabilized with intermittent boli of epinephrine and with sodium bicarbonate. With improved circulation livores and rigor disappeared. In the present case a minimal central circulation was noted, which could be stabilized, despite the presence of certain signs of death ( livores and rigor mortis). Considering the finding of an abrogated peripheral perfusion (livores), we postulate a centripetal collapse of glycogen and ATP supply in the patients left arm (rigor), which was restored after resuscitation and reperfusion. Thus, it appears that livores and rigor are not sensitive enough to exclude a vita minima, in particular in hypothermic patients with intoxications. Consequently a careful ABC-check should be performed even in the presence of apparently certain signs of death, to avoid underdiagnosing a vita minima. Additional ECG- monitoring is required to reduce the rate of false positive declarations of death. To what extent basic life support by paramedics should commence when rigor and livores are present until physician DNR order, deserves further discussion.

A fine balance'one-lung ventilation in a patient with Eisenmenger syndrome

A 38-yr-old woman with an atrial septum defect and Eisenmenger syndrome was scheduled for a lung biopsy via thoracoscopy during one-lung ventilation. Fluids were given to increase central venous pressure to 8 mm Hg, an epidural catheter was inserted at the sixth thoracic intervertebral space and ropivacaine 0.3%, 6 ml were given. Careful balance of systemic and pulmonary vascular resistance is crucial in Eisenmenger syndrome, so norepinephrine (0.14 mg kg(-1) min(-1)) was infused before general anaesthesia was started with fentanyl 4 mg kg(-1), ketamine 2 mg kg(-1), pancuronium 1 mg and succinylcholine 2 mg kg(-1). Anaesthesia was maintained with propofol 4-8 mg kg(-1) h(-1). To control pulmonary artery pressure, ventilation was performed with oxygen 100% and nitric oxide 20 ppm. Surgery and anaesthesia course were uneventful and the patient was extubated. However, pleural haemorrhage required treatment with blood components, re-intubation on the second postoperative day and removal of the haematoma by mini-thoracotomy. A step-by-step approach using a balanced combination of regional and general anaesthesia, controlled fluid administration, norepinephrine and inhaled nitric oxide preserved a stable circulation even during one-lung ventilation. The diagnostic value of lung biopsy must be weighed against the possibility of life-threatening haemorrhage.

[Thoracotomy and scoliosis surgery in a patient with a univentricular heart]

We report the case of a 15-year-old boy with a single left ventricle who underwent total cavopulmonary connection (Fontan circulation). Due to a progredient idiopathic scoliosis he had to undergo two surgical correction procedures of the vertebral column. Fontan circulation is characterized by the functional absence of the right ventricle. Blood from the systemic circulation passively flows directly into the pulmonary artery. Therefore, central venous preload as well as pulmonary vascular resistance gain essential significance for cardiac output. After volume preload, in both procedures anaesthesia was induced with etomidate and maintained intravenously with propofol and fentanyl but without N(2)O. Increases of the systemic and pulmonary vascular resistance were avoided. A central venous pressure of 20 mmHg was clinically associated with the most stable haemodynamics. In view of the elective nature of the present surgical procedures and with regard to an individual advantage vs risk estimation, tactical algorithms of action must be predefined on the basis of the individual physiology/pathophysiology to keep reaction times for necessary interventions brief.

Impact of n-3 fatty acid supplemented parenteral nutrition on haemostasis patterns after major abdominal surgery

In various diseases n-3 fatty acids exert anti-inflammatory properties. These effects seem to be related to the uptake and incorporation of eicosapentaenoic acid (EPA) into the cellular substrate pool after dietary intake of EPA, which is contained in fish oils (FO). In the state of inflammation EPA is released to compete with arachidonic acid (AA) for metabolism at the cyclo-oxygenase and the 5-lipoxygenase level. The metabolites of EPA have less inflammatory and chemotactic potency than the substances derived from AA. In addition to positive effects, early studies pointed towards prolonged bleeding times after dietary intake of n-3 fatty acids. This study was undertaken to address the issue of potential coagulation disturbances associated with postoperative parenteral FO administration. This was a prospective, randomised, double blinded clinical trial, carried out in two operative intensive care units (13 and 16 beds) in a university hospital. Forty-four patients undergoing elective major abdominal surgery participated in the trial. Patients were randomly assigned to receive total parenteral nutrition (TPN) supplemented with either soybean oil (SO, Lipovenoess 10% PLR; 1.0 g/kgBW per day; n = 20) for five days or with a combination of FO and SO (FO, Omegaven; 0.2 g/kgBW per day plus SO, Lipovenoes 10% PLR; 0.8 g/kgBW per day, n = 24), respectively. Blood samples were taken preoperatively (day -1), prior to (day 1) during (days 2-5) and after TPN (day 6). The coagulation parameters thromboplastin time (Quick), activated partial thromboplastin time (aPTT), fibrinogen and antithrombin III were measured. To differentially assess activation levels of extrinsic and intrinsic coagulation pathway, factors VIIa and XIIa were quantified. Moreover platelet function was determined by resonance thrombography. Baseline values of coagulation and platelet function were comparable in both groups, but coagulation activity dropped after surgery. Over the observation period of 6 days, however, physiological levels were regained. No clinically significant differences were observed between the SO- and SO + FO- group. These findings suggest that infusion of fish oil in doses up to 0.2 g/kgBW per day is safe regarding coagulation and platelet function.

N-acetylcysteine reduces respiratory burst but augments neutrophil phagocytosis in intensive care unit patients

OBJECTIVE

The antioxidant N-acetylcysteine (NAC) has been shown to attenuate septic tissue injury. To evaluate whether NAC affects host defense mechanisms in critically ill patients, thus predisposing to increased risk of infection, the current study focuses on neutrophil phagocytotic and burst activity after treatment with NAC.

DESIGN

Prospective, randomized, clinical trial.

SETTING

Twelve-bed operative intensive care unit in a university hospital.

PATIENTS

Thirty patients diagnosed with sepsis/systemic inflammatory response syndrome, or multiple trauma.

INTERVENTIONS

Patients were randomly assigned to receive either NAC (n = 15) for 4 days in increasing dosages (day 1: 6 g; day 2: 12 g; days 3 and 4: 18 g) or a mucolytic basis dosage of NAC (3 x 300 mg/day [control]; n = 15), respectively.

MEASUREMENTS AND MAIN RESULTS

Blood samples were taken before NAC high-dose infusion (day 1), after increasing doses of NAC (days 3 and 5) and 4 days after the last high-dose treatment (day 8). Neutrophil oxidative burst activity after stimulation with Escherichia coli and polymorphonuclear phagocytosis were determined in a flow cytometric assay. Baseline values of polymorphonuclear functions were comparable in both groups. NAC high-dose treatment resulted in a significantly improved phagocytosis activity compared with control patients. In contrast to this, polymorphonuclear burst activity was significantly reduced in the NAC high-dose treated group on day 3.

CONCLUSION

These findings suggest that infusion of NAC in high doses affects granulocyte functions in critically ill patients. Antimicrobial host defense requires the effective sequence of cell adhesion, phagocytosis, and bactericidal respiratory burst. The enhanced phagocytotic activity might be a compensatory mechanism in states of impaired respiratory burst to maintain tissue sterility. For certain mechanisms of disease, the effects observed might be favorable (e.g., ischemia/reperfusion, endothelial cell activation), for others (infection) this might be detrimental.

[Combined anesthesia with epidural catheter. A retrospective analysis of the perioperative course in patients ungoing radical prostatectomy]

Patients requiring radical prostatectomy (rPE), including retroperitoneal lymphadenectomy are often aged and have coexisting cardiopulmonary diseases, increasing the risk of perioperative complications. The aim of the present study was to evaluate our perioperative anaesthesiologic regimen over the last five years, in terms of safety and patients comfort. Records of 433 patients who underwent rPE between 1994 and 1999 in our hospital were retrospectively reviewed. Patients were divided in those who received: 1. general anaesthesia (GA) alone, 2. a combination of lumbar epidural anaesthesia (LEA) + GA or, 3. thoracic epidural anaesthesia (TEA) + GA. General anaesthesia was performed as balanced anaesthesia, and epidural administered local anaesthetics were bupivacaine 0.25% or ropivacaine 0.2%, 8-12 ml/h. In terms of intra- and postoperative numbers of tachycardiac and hypertensive episodes, a reduced stress response was observed under epidural anaesthesia (EA). Moreover, the weaning duration was shorter under EA and onset of gastrointestinal motility was found earlier ([h] GA: 50.6 +/- 11.1/LEA: 39.3 +/- 13.6/TEA: 33.8 +/- 13.0). Furthermore, a trend to rarer phases of postoperative vomiting and a significant decrease of in hospital stay of about one day ([d] GA: 12.4 +/- 5.8/LEA: 11.1 +/- 3.1/TEA: 11.5 +/- 3.8) was observed. The duration of personnel binding in the OR did not differ significantly between GA and TEA ([min] GA: 222.9 +/- 43.5/LEA: 238.2 +/- 41.8/TEA: 227.0 +/- 46.2), but ICU stay was shortened under TEA. Besides this, TEA reduced the number of pathologic postoperative thorax-x-rays. Senso-motor blockades, decreases of SaO2 and cardiac complications were experienced more frequent under LEA as compared with TEA. Combination of GA and EA, especially TEA, appears to improve perioperative care of patients undergoing rPE, in terms of patients safety and comfort.

Epidural abscess after epidural catheter for pain release during pancreatitis

BACKGROUND

Despite knowledge about compromised host defence in the course of diabetes mellitus and pancreatitis, epidural analgesia (EA) is recommended for pain management during pancreatitis.

CASE REPORT

We present the case of a diabetic patient with pancreatitis who developed an epidural abscess after 3 days with an epidural catheter. Natural killer and T-helper cell counts were distinctively reduced in the absence of HIV serology. Furthermore, a synthesis failure of the liver was observed and evidenced by low cholinesterase, low whole protein fraction and low antithrombin III in the peripheral blood.

CONCLUSION

We suggest that the combination of pancreatitis, diabetes and compromised immunity might be a contraindication to epidural analgesia.