Directed flow of identified particles in Au+Au collisions at √[SNN]=200 GeV at RHIC

STAR's measurements of directed flow (v1) around midrapidity for π±, K±, KS0, p, and p[over ¯] in Au+Au collisions at √[sNN]=200  GeV are presented. A negative v1(y) slope is observed for most of produced particles (π±, K±, KS0, and p[over ¯]). In 5%-30% central collisions, a sizable difference is present between the v1(y) slope of protons and antiprotons, with the former being consistent with zero within errors. The v1 excitation function is presented. Comparisons to model calculations (RQMD, UrQMD, AMPT, QGSM with parton recombination, and a hydrodynamics model with a tilted source) are made. For those models which have calculations of v1 for both pions and protons, none of them can describe v1(y) for pions and protons simultaneously. The hydrodynamics model with a tilted source as currently implemented cannot explain the centrality dependence of the difference between the v1(y) slopes of protons and antiprotons.

Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at √S(NN)=200 GeV

We report transverse momentum (p(T)≤15  GeV/c) spectra of π(±), K(±), p, p[over ¯], K(S)(0), and ρ(0) at midrapidity in p+p and Au+Au collisions at √S(NN)=200  GeV. Perturbative QCD calculations are consistent with π(±) spectra in p+p collisions but do not reproduce K and p(p[over ¯]) spectra. The observed decreasing antiparticle-to-particle ratios with increasing p(T) provide experimental evidence for varying quark and gluon jet contributions to high-p(T) hadron yields. The relative hadron abundances in Au+Au at p(T)≳8  GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.

Strangeness enhancement in Cu-Cu and Au-Au collisions at √S(NN)=200 GeV

We report new STAR measurements of midrapidity yields for the Λ, Λ[over ¯], K(S)(0), Ξ(-), Ξ[over ¯](+), Ω(-), Ω[over ¯](+) particles in Cu+Cu collisions at √S(NN)==200  GeV, and midrapidity yields for the Λ, Λ[over ¯], K(S)(0) particles in Au+Au at √S(NN)==200  GeV. We show that, at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parametrization based on the fraction of participants that undergo multiple collisions.

Measurement of the parity-violating longitudinal single-spin asymmetry for W± boson production in polarized proton-proton collisions at sqrt[s] = 500 GeV

We report the first measurement of the parity-violating single-spin asymmetries for midrapidity decay positrons and electrons from W+ and W- boson production in longitudinally polarized proton-proton collisions at sqrt[s] = 500 GeV by the STAR experiment at RHIC. The measured asymmetries, A(L)(W+) = -0.27 ± 0.10(stat.) ± 0.02(syst.) ± 0.03(norm.) and A(L)(W-) = 0.14 ± 0.19(stat.) ± 0.02(syst.) ± 0.01(norm.), are consistent with theory predictions, which are large and of opposite sign. These predictions are based on polarized quark and antiquark distribution functions constrained by polarized deep-inelastic scattering measurements.

Measurement of the bottom quark contribution to nonphotonic electron production in p + p collisions at √s=200 GeV

The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at √s=200  GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of pT≥5  GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high pT.

Higher moments of net proton multiplicity distributions at RHIC

We report the first measurements of the kurtosis (κ), skewness (S), and variance (σ2) of net-proton multiplicity (Np-Np) distributions at midrapidity for Au+Au collisions at square root of s(NN)=19.6, 62.4, and 200 GeV corresponding to baryon chemical potentials (μB) between 200 and 20 MeV. Our measurements of the products κσ2 and Sσ, which can be related to theoretical calculations sensitive to baryon number susceptibilities and long-range correlations, are constant as functions of collision centrality. We compare these products with results from lattice QCD and various models without a critical point and study the square root of s(NN) dependence of κσ2. From the measurements at the three beam energies, we find no evidence for a critical point in the QCD phase diagram for μB below 200 MeV.

Three-particle coincidence of the long range pseudorapidity correlation in high energy nucleus-nucleus collisions

We report the first three-particle coincidence measurement in pseudorapidity (Δη) between a high transverse momentum (p⊥) trigger particle and two lower p⊥ associated particles within azimuth |Δϕ|<0.7 in square root of s(NN)=200 GeV d+Au and Au+Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Δη correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Δη. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.

Azimuthal charged-particle correlations and possible local strong parity violation

Parity-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the system's orbital momentum axis. We investigate a three-particle azimuthal correlator which is a P even observable, but directly sensitive to the charge separation effect. We report measurements of charged hadrons near center-of-mass rapidity with this observable in Au + Au and Cu + Cu collisions at square root of s(NN) = 200 GeV using the STAR detector. A signal consistent with several expectations from the theory is detected. We discuss possible contributions from other effects that are not related to parity violation.

Growth of long range forward-backward multiplicity correlations with centrality in Au + Au collisions at square root of sNN = 200 GeV

Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au + Au and p + p collisions at square root of s(NN) = 200 GeV. Strong short- and long-range correlations (LRC) are seen in central Au + Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short-range correlations are observed in peripheral Au + Au collisions. Both the dual parton model (DPM) and the color glass condensate (CGC) predict the existence of the long-range correlations. In the DPM, the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC, longitudinal color flux tubes generate the LRC. The data are in qualitative agreement with the predictions of the DPM and indicate the presence of multiple parton interactions.

K/pi Fluctuations at relativistic energies

We report K/pi fluctuations from Au + Au collisions at sqrt[s(NN)]= 19.6, 62.4, 130, and 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider. K/pi fluctuations in central collisions show little dependence on incident energy and are on the same order as those from NA49 at the Super Proton Synchrotron in central Pb + Pb collisions at sqrt[s(NN)]=12.3 and 17.3 GeV. We report results for the collision centrality dependence of K/pi fluctuations and results for charge-separated fluctuations. We observe that the K/pi fluctuations scale with the charged particle multiplicity density.

Observation of two-source interference in the photoproduction reaction AuAu --> AuAurho0

In ultraperipheral relativistic heavy-ion collisions, a photon from the electromagnetic field of one nucleus can fluctuate to a quark-antiquark pair and scatter from the other nucleus, emerging as a rho{0}. The rho{0} production occurs in two well-separated (median impact parameters of 20 and 40 F for the cases considered here) nuclei, so the system forms a two-source interferometer. At low transverse momenta, the two amplitudes interfere destructively, suppressing rho{0} production. Since the rho{0} decays before the production amplitudes from the two sources can overlap, the two-pion system can only be described with an entangled nonlocal wave function, and is thus an example of the Einstein-Podolsky-Rosen paradox. We observe this suppression in 200 GeV per nucleon-pair gold-gold collisions. The interference is 87%+/-5%(stat.)+/-8%(syst.) of the expected level. This translates into a limit on decoherence due to wave function collapse or other factors of 23% at the 90% confidence level.

Indications of conical emission of charged hadrons at the BNL relativistic heavy ion collider

Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be theta=1.37+/-0.02(stat)-0.07+0.06(syst), independent of p_{ perpendicular}.

System-size independence of directed flow measured at the BNL relativistic heavy-ion collider

We measure directed flow (v_{1}) for charged particles in Au+Au and Cu+Cu collisions at sqrt[s_{NN}]=200 and 62.4 GeV, as a function of pseudorapidity (eta), transverse momentum (p_{t}), and collision centrality, based on data from the STAR experiment. We find that the directed flow depends on the incident energy but, contrary to all available model implementations, not on the size of the colliding system at a given centrality. We extend the validity of the limiting fragmentation concept to v_{1} in different collision systems, and investigate possible explanations for the observed sign change in v_{1}(p_{t}).

Forward neutral-pion transverse single-spin asymmetries in p + p collisions at sqrt[s] = 200 GeV

We report precision measurements of the Feynman x (xF) dependence, and first measurements of the transverse momentum (pT) dependence, of transverse single-spin asymmetries for the production of pi0 mesons from polarized proton collisions at sqrt[s] = 200 GeV. The xF dependence of the results is in fair agreement with perturbative QCD model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the pT dependence at fixed xF are not consistent with these same perturbative QCD-based calculations.

Longitudinal double-spin asymmetry for inclusive jet production in p[over -->] + p[over -->] collisions at sqrt[s]=200 GeV

We report a new STAR measurement of the longitudinal double-spin asymmetry A(LL) for inclusive jet production at midrapidity in polarized p + p collisions at a center-of-mass energy of sqrt[s]=200 GeV. The data, which cover jet transverse momenta 5<p(T)<30 GeV/c, are substantially more precise than previous measurements. They provide significant new constraints on the gluon spin contribution to the nucleon spin through the comparison to predictions derived from one global fit to polarized deep-inelastic scattering measurements.

Measurement of transverse single-spin asymmetries for Dijet production in proton-proton collisions at sqrt[s]=200 GeV

We report the first measurement of the opening angle distribution between pairs of jets produced in high-energy collisions of transversely polarized protons. The measurement probes (Sivers) correlations between the transverse spin orientation of a proton and the transverse momentum directions of its partons. With both beams polarized, the wide pseudorapidity (-1< or = eta < or = +2) coverage for jets permits separation of Sivers functions for the valence and sea regions. The resulting asymmetries are all consistent with zero and considerably smaller than Sivers effects observed in semi-inclusive deep inelastic scattering. We discuss theoretical attempts to reconcile the new results with the sizable transverse spin effects seen in semi-inclusive deep inelastic scattering and forward hadron production in pp collisions.

Partonic Flow and phi-Meson production in Au+Au collisions at sqrt radical sNN = 200 GeV

We present first measurements of the phi-meson elliptic flow (v2(pT)) and high-statistics pT distributions for different centralities from radical sNN=200 GeV Au+Au collisions at RHIC. In minimum bias collisions the v2 of the phi meson is consistent with the trend observed for mesons. The ratio of the yields of the Omega to those of the phi as a function of transverse momentum is consistent with a model based on the recombination of thermal s quarks up to pT approximately 4 GeV/c, but disagrees at higher momenta. The nuclear modification factor (R CP) of phi follows the trend observed in the K S 0 mesons rather than in Lambda baryons, supporting baryon-meson scaling. These data are consistent with phi mesons in central Au+Au collisions being created via coalescence of thermalized s quarks and the formation of a hot and dense matter with partonic collectivity at RHIC.

Involvement of an anaesthetic department in terminal therapy

The goal of hospital treatment in terminal therapy must be a functional integration of all modes of care including psychosocial support. Anaesthesiologists who practise pain management and critical care medicine are predestined to care for terminally ill patients and their families. An anaesthetic department can assume superordinate responsibilities within the organization of a palliative network coordinating inpatient and outpatient arrangements.

Transverse momentum and centrality dependence of high-pT nonphotonic electron suppression in Au+Au collisions at sqrt[s NN]=200 GeV

The STAR collaboration at the BNL Relativistic Heavy-Ion Collider (RHIC) reports measurements of the inclusive yield of nonphotonic electrons, which arise dominantly from semileptonic decays of heavy flavor mesons, over a broad range of transverse momenta (1.2<p(T)<10 GeV/c) in p+p, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV. The nonphotonic electron yield exhibits an unexpectedly large suppression in central Au+Au collisions at high p(T), suggesting substantial heavy-quark energy loss at RHIC. The centrality and p(T) dependences of the suppression provide constraints on theoretical models of suppression.

[Advance directives in the prehospital setting -- emergency physicians' attitudes]

OBJECTIVE

The German physician based emergency medical system (EMS) might confront physicians with advance directives in the field. A multi-question survey was used to evaluate emergency physicians' experience with advance directives in the prehospital setting and to assess their attitudes towards forms and statements of advance directives.

METHODS

A questionnaire was mailed to the members of the Association of Emergency Physicians of Northern Germany ("AGNN"), an interest group of emergency physicians, in 2001.

RESULTS

511 emergency physicians (50,4 % of the AGNN members) filled in the questionnaire completely and sent it back for evaluation. 75 % of the participants were working as emergency physicians at present, 72 % had emergency experiences of more than 5 years. One third had previously dealt with advance directives in the prehospital setting. 77 % of these physicians thought advance directives generally helpful. Nevertheless 88 % based their management on the context of the individual circumstances (e. g. emergency conditions, underlying diseases, expected prognosis), only 7 % said they would always exactly follow the statements of the directive. In the view of the emergency physicians the advance directive should contain information on cardiopulmonary resuscitation (CPR: 88 %), intensive care-treatment (75 %) and preclinical emergency treatment (55 %). Information on underlying diseases (87 %) and a legal substitute (84 %) should be contained as well. As formal requirements, 47 % of the physicians wanted the family doctor to be involved, 49 % desired a notary authenticity confirmation, additionally or solely. Pragmatically, the advance directive should be kept with the personal documents (84 %). A regular reconfirmation was deemed necessary (twice to once a year: 64 %). The current legal situation was regarded as unclear by 81 % of the emergency physicians, 85 % favored a unique, officially authorized type of directive.

CONCLUSION

The high number of returned questionnaires shows the importance of the topic "advance directives" for emergency physicians. Despite some practical and legal problems, a big majority of the experienced emergency physicians in this survey thought the advance directives in the prehospital setting to be helpful. A clear statement on resuscitation as well as simplification of the many existing types of directives are the most essential requirements demanded by the emergency physicians. A solution could be the creation of an extra "emergency advance directive".

[New pathways in undergraduate medical education - first experiences with the cross section speciality emergency and intensive care medicine]

OBJECTIVE

On October 1 (st) 2003 Emergency Medicine was recognised for the first time as an independent cross section speciality in the new German "Approbationsordnung fuer Aerzte" (Medical Licensing Regulations). These amendments were made not only to increase the amount of small group teaching sessions but also to encourage a multidisciplinary and rather practical approach to the related topics. This article portrays the realisation of these objectives in form of a multidisciplinary module, as it has been established at University of Göttingen Medical School since the summer semester of 2004. We present the new curriculum, calculate the associated personnel resources and demonstrate the results of the structured evaluation given by the participating students.

METHODS

We linked the fields of emergency and intensive care medicine by splitting them up into submodules which the students had to run through according to a set rota. 162 students were allocated to 27 small groups. Every student received a total of 38.5 hours of teaching, with the workshops coming to 46.8 %. The workshops comprised of nine sessions, three in Emergency Medicine, four in Intensive Care Medicine and two at human patient simulators. In addition we scheduled a seminar and an accompanying lecture. The final examination was performed as an Objective Structured Clinical Evaluation (OSCE).

RESULTS

The realisation of the new module required a total of 1290 working hours for medical staff and 130 for our student aids. Compared to all other modules of Goettingen University Medical School the module here presented obtained the highest overall evaluation score by the medical students. Lessons with a high amount of practical involvement (i. e. Emergency Medicine and simulator-based workshops) were significantly better evaluated than rather formal teaching techniques, such as the lectures and the seminar. According to the students' self-assessment the simulator-based workshops were seen particularly valuable for the facilitation of knowledge transfer into clinical practice.

CONCLUSION

The determined realisation of the new German Medical Licensing Regulations requires considerable time resources. However, its evaluation by the medical students is strikingly positive.

Do intracellular, extracellular or urinary magnesium concentrations predict renal retention of magnesium in critically ill patients?

BACKGROUND AND OBJECTIVE

Magnesium disorders are common in hospitalized patients. In patients with low or normal magnesium, the intravenous magnesium loading test has been demonstrated to be a sensitive test to assess magnesium deficiency in critically ill patients. However, it is more time consuming and more difficult than the measurement of intracellular or extracellular magnesium concentrations. This study evaluated whether erythrocyte, plasma and urinary magnesium concentrations predict renal magnesium retention measured by th magnesium loading test.

METHODS

One-hundred-and-three intensive care patients (36 females, 67 males) in a tertiary care centre and 41 healthy subjects (13 females, 28 males) took part in this prospective study. Intracellular, total plasma, ionize extracellular and urinary magnesium concentrations were measured and also magnesium retention by intravenous magnesium loading test.

RESULTS

Total plasma magnesium concentration was poorly correlated with magnesium retention (r = 0.36 r2 = 0.13) and was the only parameter that significantly predicted magnesium retention in intensive care patients (P < 0.01). However, only 10% of the magnesium retention data were linked to the total plasma magnesium concentration.

CONCLUSIONS

Total plasma magnesium concentration predicts magnesium retention in critically ill intensive care patients but not intracellular and urinary magnesium concentrations. Only a small proportion of the magnesium retention was due to the total plasma magnesium concentration.

Erhaltene Spontanatmung und stabile Hämodynamik trotz schwerer akzidentieller Hypothermie (22 °C)

We present a case of severe accidental hypothermia (core temperature 22 degrees C) after a suicide attempt. The initial symptoms and the pre-hospital and hospital treatment are discussed. Additionally, different rewarming strategies for patients with severe accidental hypothermia are compared.

Untersuchung zur Befindlichkeit von beatmeten Patienten

OBJECTIVE

It is very important to investigate the patient's disability and pain. Interviews of intubated and tracheotomised patients were neglected because of inadaequate measuring methods. This is the first prospective study that evaluates the disability and pain of intubated and tracheotomised patients.

METHODS

Disability, Hospital Anxiety and Depression Scale, Visuelle Analogue Scale, Glasgow Coma Scale and structured questions were used to investigate the disability and pain of ventilated patients. 26 patients of an interdisciplinary operative intensive care unit took part in the study. Sociodemographic parameters, ventilation, sedation and pain were evaluated. Doctors and nurses were asked to assess the patient's pain and disability.

RESULTS

17 intubated and 9 tracheotomised patients were included in the study. Mean intensity of pain was 30.3 (SD = 31.4), anxiety 40.8 (SD = 31.4), disability 30.0 (SD = 11.5) and disability caused by ventilation 61.9 (SD = 28.5). 46.2 % of the patients had a pathological subscale of anxiety and 50 % of depression in the Hospital Anxiety and Depression Scale. Nurses assessed the patient's disability and pain better than the doctors.

CONCLUSION

A high disability has to be taken in account in the therapy of intubated and tracheotomised patients.

[To resuscitate or not? The emergency physician's decision in the prehospital setting]

OBJECTIVE

To identify factors affecting the decision to withhold resuscitative attempts or to terminate cardiopulmonary resuscitation (CPR) in the prehospital setting.

METHODS

In a physician-based emergency medical system (EMS) standardised interviews with the emergency physicians were performed within 24 hours after unsuccessful or withheld CPR-efforts.

RESULTS

Over a period of one year 170 prehospital cardiac arrests were evaluated. 47 patients (28 %) were declared dead on arrival by the emergency physician. The decision to withhold CPR was based on obvious clinical signs of death (32 patients) or the diagnosis of cardiac arrest due to severe trauma (8 patients). In 4 cases the terminal state of a fatal illness was the emergency physician's criterion not to initiate resuscitative efforts. In 3 patients an extended response time (more than 10 minutes) was mentioned, in combination with a primary rhythm of either asystole or electromechanical dissociation and additional information given by the family doctor. In 123 patients CPR was attempted. In 72 cases (59 %) resuscitative efforts were terminated as no return and stabilisation of spontaneous circulation was achieved. In 58 patients the decision to stop CPR was based on the evidence of cardiac death. Additional criteria for the termination of the resuscitation attempt were the duration of CPR, an extended response time, pre-existing diseases, age, pupillary status, missing brain stem reflexes, the reason of cardiac arrest, information given by the family or the family doctor and secondarily evolving signs of death. In 14 patients the emergency physicians reported that their decision to terminate CPR was primarily based on these co-factors, the evidence of cardiac death was not explicitly mentioned in these cases.

CONCLUSION

In the pre-hospital setting the decision to withhold or to withdraw CPR is mostly based on reliable criteria such as obvious clinical signs of death, fatal trauma or evidence of cardiac death. Nevertheless, in a small but considerable number of cases exceptions to this rule are made by emergency physicians.

High-dose midazolam and the attenuation of the contractile response to vasoconstrictors in coronary artery segments

BACKGROUND AND OBJECTIVE

Benzodiazepines may cause hypotension and are reported to interfere with smooth vascular muscle activity. The aim was to elucidate the influence of three different benzodiazepines on the vascular reactivity of coronary arteries.

METHODS

Using the model of isolated vessels, we studied the impact of midazolam (0.15, 1.5, 15 microg mL(-1)), diazepam (0.1, 1.0, 10 microg mL(-1)) and flunitrazepam (0.01, 0.1, 1.0 microg mL(-1)) on the contractile responses to histamine (2 x 10(-5) mol L(-1)) and serotonin (3 x 10(-5) mol L(-1)) in isolated intact and denuded coronary arteries.

RESULTS

Midazolam significantly attenuated the contractile response when administered in high concentrations (15 microg mL(-1)). This effect was more pronounced in intact than in denuded preparations (histamine: -22.7 versus -7.3%, P = 0.0079; serotonin: -47.1 versus -15.9%, P < 0.0001). Diazepam and flunitrazepam exerted no significant effects on the vascular tone of coronary arteries.

CONCLUSIONS

Midazolam, but not diazepam or flunitrazepam, attenuates the contractile responses to vasoconstrictors in concentrations beyond those used in clinical practice. This effect is in part mediated by endothelial factors.

[Symptom control in palliative medicine]

Palliative medicine has as its goal improving the quality of life of patients with incurable diseases and their family members. According to the WHO, alleviating pain and other physical symptoms, as well as addressing psycho-social and spiritual problems have the highest priority. The role of medicine and the physician is inseparably linked to psycho-social and nursing resources in a multi-disciplinary team. Advanced stages of cancer are particularly characterized by symptoms which can cause lasting impairment of normal life. In addition to pain, patients suffer from other, often extremely distressing physical symptoms such as constipation, nausea and vomiting, gastrointestinal obstruction and difficulty in breathing. The first priority is to determine the causes of the individual symptoms, since therapeutic decisions are based on the specific pathophysiological mechanisms. Effective symptom management presupposes exact knowledge of the pharmacokinetics. The often difficult decision between causal and symptomatic therapy options must - whenever possible - be made together with the patient and frequently in interdisciplinary medical consultation. Tumor pain therapy follows the guidelines of the World Health Organization. Crucial are long-term therapy and dose titration of the analgesics, stepped progression between the groups of medication, and specific therapy approaches for neuropathic pain components. The significance of constipation with its variety of possible complications is often underestimated in the context of the tumor patient. Effective prophylaxis and cause-based therapy do improve the nutritional care and can help to prevent the transition to an ileus. New findings concerning the role of neurotransmitters in triggering nausea and vomiting have opened up specific methods of attack. Dyspnoea therapy places high demands on the medical team, since nursing measures must effectively supplement the more limited medical possibilities.

Cost-effectiveness of anaesthesia

Cost-effectiveness analyses of anaesthesia regimens will become more and more important in the future because of increasing pressure to reduce the cost of health care. Inhalational and intravenous techniques are vying for the position of being the most cost-effective form of general anaesthesia. However, erroneous or misleading results are a considerable risk if the boundary conditions of the analyses are not chosen carefully. Recent comparative studies on this topic are analyzed with regard to their results and to the premises under which they were conducted.

Influence of opioids on the vascular tone of isolated porcine coronary artery segments

BACKGROUND

It was the aim of this study to elucidate the influence of opioids on coronary vascular tone using the model of isolated porcine coronary artery segments.

METHODS

We studied the effects of fentanyl (0.01, 0.1, 1.0 microg ml(-1)), alfentanil (0.1, 1.0, 10 microg ml(-1)), and sufentanil (0.01, 0.1, 1.0 microg ml(-1)) on the contractile response to three vasoconstrictors, acetylcholine, histamine and serotonin.

RESULTS

Fentanyl (0.1, 1.0 microg x ml(-1)) dose-dependently attenuated the contractile response to acetylcholine, but not to histamine and serotonin. There were no differences in fentanyl's vasorelaxing potency between rings with intact and denuded endothelium. Alfentanil and sufentanil did not exert any significant influence on any of the vasoconstrictors tested.

CONCLUSION

It is concluded that, in isolated porcine coronary artery rings, fentanyl at high concentrations has an attenuating effect on acetylcholine-induced contractions, which is independent of endothelial function, whereas alfentanil and sufentanil do not influence coronary vascular tone.

[Treatment of constipation and different laxative requirements in palliative medicine]

The significance of constipation with its variety of possible complications is often underestimated in the context of the tumour patient's complaints although difficulties in stool management are more common in patients with advanced cancer than in those with other terminal diseases. Without treatment constipated patients will suffer from nausea and emesesis and will possibly develop small bowel paralysis. About half of all patients admitted to specialist palliative care units report constipation, but about 75% of the patients will require laxatives. Unlike for pain, no generally accepted and widely disseminated management guidelines are available. Effective prophylaxis and cause-based therapy do improve the alimentary condition and can help to prevent the transition to ileus situations. Effective symptom management presupposes exact knowledge of the pharmacokinetics.

[Basics of drug therapy of cancer pain]

Industrial countries experience a significant increase of cancer prevalence. Despite recent advances in the treatment of various types of cancer still most of the patients cannot be cured. Especially the advanced incurable stages of cancer, however, often are accompanied by severe pain. Therefore, the high demand for a sufficient pain management and symptom control seems obvious. Throughout the last decades new drugs and techniques for the management of cancer pain have been developed. Most cancer patients should experience sufficient pain-management if existing recommendations for the pharmacological treatment of cancer pain (e.g. WHO-guidelines) are followed consequently. If, nevertheless, intractable pain or ongoing disabling symptoms continue despite proper therapy, every doctor should feel himself obliged to consult an expert in palliative medicine, in order not to tolerate avoidable suffering of his patient.

Do muscle relaxants influence vascular tone in isolated coronary artery segments?

The aim of this study was to elucidate the influence of four neuromuscular blocking substances on coronary vascular tone using the model of isolated porcine coronary artery segments. We studied the effects of four muscle relaxants, atracurium, pancuronium, rocuronium, and vecuronium (0.1, 1, and 10 microg mL-1 each), on the contractile response to three vasoconstrictors: acetylcholine, histamine, and serotonin. None of the neuromuscular blocking agents under investigation exerted a significant influence on the vasoconstricting effects of these mediators except for pancuronium, which dose-dependently attenuated acetylcholine-mediated contractions (-10.8% attenuation for 10 microg mL-1 pancuronium, P < 0.05). There was no difference between vessels with intact endothelium and denuded preparations. It is concluded that high-dose pancuronium exerts an antimuscarinic effect in vascular smooth muscle. The other neuromuscular agents studied do not alter vascular reactivity of isolated porcine coronary arteries.

Propofol and thiopental attenuate the contractile response to vasoconstrictors in human and porcine coronary artery segments

The effects of propofol and thiopental on three vasoconstrictors, acetylcholine, histamine, and serotonin were studied in isolated porcine and human coronary artery rings. Propofol and thiopental attenuated the contractile response to all mediators in a dose-dependent manner. This dilating effect was fairly weak using low concentrations (propofol 1 microg mL-1 and 10 microg mL-1, thiopental 5 microg mL-1 and 10 microg mL-1). In the presence of high concentrations (propofol 100 microg mL-1, thiopental 50 microg mL-1) marked relaxation was observed (propofol -32% up to -49%, P < 0,05; thiopental -23% up to -67%, P < 0.05). These dilating effects were seen both in intact and denuded rings, the differences were not significant. Human coronary artery segments were relaxed by thiopental (-22% to -76%) and propofol (-11% to -67%) to a similar extent. Our data indicate that propofol and thiopental relax isolated coronary segments in a dose-dependent manner, and that there is no evidence that these effects are dependent of endothelial factors.

[Euthanasia in Europe--ten countries with special consideration of the Netherlands and Germany]

This article presents an overview of the current situation of euthanasia in Europe. Emphasis is given to the positions discussed in the Netherlands and in Germany. The current situation, the development of the legal positions, and the resulting debate are established by analysing English and German anesthesiological and medical-ethical journals. It has to be noted that many physicians are not satisfied with the terminology of euthanasia. The traditional concepts of euthanasia do not cover the aspect of accompanying terminally ill persons until they have died. The differentiation of active, passive, and indirect euthanasia does not correspond to the practical handling of the problem. Many physicians are in need of an open discussion of euthanasia-related issues. The way euthanasia is practiced in the Netherlands has strongly influenced the further development of the debate in Europe. Even though the Dutch model is rejected by the jurisdications of virtually all other countries, and official statements of medical corporations stick to the disapproval of active euthanasia, studies examining the attitudes towards euthanasia and the treatment of it in daily routine show that active interventions to shorten life are performed to different degrees outside of the Netherlands as well.

[Emergency and intensive care medicine as an interdisciplinary training requirement]

While substantial and practical qualification for medical practice within the framework of emergency medical services have to be proven by an advanced training, there are no special training programs for in-hospital emergency situations. As in the emergency room a transparent in-hospital emergency management has to be established including definite competencies to avoid time delays and inadequate treatment due to disputes about competence. Especially surgical intensive care medicine is an interdisciplinary task, requiring the participation of the surgeon as a responsible partner. Thus, the physician working in ICUs needs professional qualification and specialized knowledge as well as marked competence to co-operate. In any case the final clinical responsibility has to be taken over by physicians who not only have performed their internship on a ICU but are highly qualified in the whole range of intensive care medicine including all topics required in advanced intensive care medicine curricula.

[Pain therapy in tumor patients and in palliative medicine. 1: Drug therapy]

Like other industrial countries Germany experiences a significant increase of cancer prevalence. Recent advances in the treatment of various types of cancer resulted in prolonged survivaltimes of patients. Cancer--especially in advanced incurable stages--often is accompanied by severe pain. Therefore, the need for sufficient pain management and symptomcontrol is obvious. Throughout the last decades new drugs and techniques for the management of cancer-pain have been developed. Most cancer-patients should experience sufficient pain-management if existing recommendations for the pharmacological treatment of cancer-pain (e.g. WHO-guidelines) are followed consequently. In case of intractable pain or ongoing disabling symptoms despite proper therapy consultation of an expert in palliative medicine should always be considered as well as the option to refer the patient to a specialized pain-management center.