A deep Chandra observation of the poor cluster AWM4 - II. The role of the radio jets in enriching the intra-cluster medium

We use a Chandra observation of the poor cluster AWM4 to map the temperature and abundance of the intra-cluster medium, so as to examine the influence of the central radio galaxy on its environment. While the cluster core is generally enriched to near-solar abundances, we find evidence of super-solar abundances correlated with the radio jets, extending ~35 kpc from the core of the central dominant galaxy NGC 6051 along its minor axis. We conclude that the enriched gas has been transported out of the central galaxy through the action of the radio source. We estimate the excess mass of iron in the entrained gas to be ~1.4x10^6 Msol, and find that this can be produced in the core of NGC 6051 within the timescale of the AGN outburst. The energy required to transport this gas to its current location is ~4.5x10^57 erg, a significant fraction of the estimated total mechanical energy output of the AGN, though this estimate is dependent on the degree of enrichment of the uplifted gas. The larger near-solar abundance region is also compatible with enrichment by metals mixed outward from NGC 6051 over a much longer timescale.Comment: Accepted for publication in MNRAS, 11 pages, 6 figure

Anesthésie et sécurité des procédures en dehors du bloc opératoire: "l'affaire de tous"

peer reviewedSuite aux progrès technologiques, l’activité anesthé- sique hors du bloc opératoire connaît un essor de plus en plus important. La majorité des procédures anesthésiques réalisées en dehors du bloc opératoire le sont pour des endoscopies diges- tives; le reste se partage entre les procédures radiologiques, les sysmothérapies ou encore les cardioversions. La pratique de l’anesthésie en dehors du bloc opératoire présente des difficul- tés essentiellement logistiques avec de nombreuses contrain- tes de temps et d’espace pour l’anesthésiste-réanimateur. Le recours à un anesthésiste-réanimateur en dehors du bloc opéra- toire est généralement motivé par un inconfort ou une douleur propre à la procédure réalisée, l’absence volontaire ou non de collaboration du patient (enfant, trouble psychiatrique comme la claustrophobie), l’existence d’une situation cliniquement ins- table ou d’un état clinique extrêmement précaire (ce sont les compétences en réanimation qui seront ici nécessaires). La mise au point pré-opératoire, le monitoring approprié et le choix de la technique ainsi que des produits adéquats permettent d’opti- miser une activité anesthésique volontiers banalisée, mais dont les risques sont superposables à ceux d’une anesthésie générale au quartier opératoire.Due to important technological improvements, anesthesiological activity outside the operating theatre is increasing. Most of these procedures are performed for gastro- enterology procedures; other procedures include medical ima- ging, electroconvulsive therapy or cardioversion. The practice of anesthesia at alternative sites is associated with logistical dif- ficulties with many constraints. Anesthesia will be requested if the procedure is likely to be unpleasant or painful, if the patient is not cooperative, or if the patient’s hemodynamic condition is unstable. The pre-anesthesia assessment, an adequate monito- ring and an appropriate choice of the anesthetic technique and drugs will be helpful in managing an anesthetic procedure too frequently neglected despite it is associated with risks similar to procedures performed in the operating theatre

New approaches and old controversies to postoperative pain control following cardiac surgery

peer reviewedObjective: To evaluate the effect of postoperative pain control in cardiac surgical patients on morbidity, mortality and other outcome measures. Background: New approaches in pain control have been introduced over the past decade. The impact of these interventions, either alone or in combination, on perioperative outcome was evaluated in cardiac surgical patients. Methods: We searched Medline for the period of 1980 to the present using the key terms analgesics, opioid, non-steroidal anti-inflammatory drugs, cardiac surgery, regional analgesia, spinal, epidural, fast-track cardiac anaesthesia, fast-track cardiac surgery, myocardial ischaemia, myocardial infarction, postoperative care, accelerated care programmes, postoperative complications, and we examined and discussed the articles that were identified to be included in this review. Results: Pain management in cardiac surgery is becoming more important with the establishment of minimally invasive direct coronary artery bypass surgery and fast-track management of conventional cardiac surgery patients. Advances have been made in this area and encompass specific techniques, such as central neuraxial blockade or selective nerve blocks, and drugs (opioids, sedative-hypnotics and non-steroidal anti-inflammatory drugs). Ideally, these therapies provide not only patient comfort but also mitigate untoward cardiovascular responses, pulmonary responses, and other inflammatory and secondary sympathetic responses. The introduction of these newer approaches to perioperative care has reduced morbidity, but not mortality, in cardiac surgical patients. Conclusions: Understanding perioperative pathophysiology and implementation of care regimes to reduce the stress of cardiac surgery, will continue to accelerate rehabilitation associated with decreased hospitalization and increased satisfaction and safety after discharge. Reorganization of the perioperative team (anaesthesiologists, surgeons, nurses and physical therapists) will be essential to achieve successful fast-track cardiac surgical programmes. Developments and improvements of multimodal interventions within the context of 'fast-track' cardiac surgery programmes represents the major challenge for the medical professionals working to achieve a 'pain and risk free' perioperative course

surgical Left Ventricular Remodelling Via Endoventriculoplasty: Clinical Observation

peer reviewedA case of dilated ischemic cardiomyopathy, with severely impaired left ventricular systolic function, treated by endoventriculoplasty and CABG, is reported. The authors discuss the modern concepts regarding the surgical treatment of large anterior asynergic scars following occlusion of the LAD. Since there are more similarities between akinesia and dyskinesia than previously thought, the endoventriculoplasty of DOR may constitute a new way to surgically remodel the left ventricle in dilated cardiomyopathies with large anterior akinesia. This surgery significantly improves the ventricular function and the overall patients' prognosis at short and mid term follow up

Regional anesthesia and antiagregants: Is it worth using them?

peer reviewe

Effect of hydroxyethylstarch on renal function in cardiac surgery: A large scale retrospective study

BACKGROUND: Recent reports indicated negative effects of hydroxyethylstarch (HES) on renal function. The goal of this large scale retrospective study was to detect whether there was an association between postoperative deterioration of renal function and the use of HES 200 kD, 0.5 DS in the cardiac surgery setting. METHODS: Retrospective analysis of daily collected data in 3124 patients who underwent coronary artery bypass and/or valvular surgery. Three groups were compared according to differences in fluid therapy: --GEL: gelatin was used as priming fluid of extracorporeal circulation (ECC) and for postoperative filling (n = 1276). --MIX: HES was used as priming fluid of ECC an gelatin was used for postoperative filling (n = 1008). --HES: HES was used as priming fluid of ECC and for postoperative filling (n = 840). MAIN RESULTS: There were no significant differences in postoperative serum creatinine concentrations between the 3 groups: GEL: 12,2 +/- 0,5 mg/l; MIX: 12,3 +/- 0.5 mg/l; HES: 12,3 +/- 0.6 mg/l. The need for postoperative extrarenal epuration was not significantly different between the 3 periods: GEL: 2,9%; MIX: 3,1%; HES: 3,8%. CONCLUSION: The use of HES 200 kD, 0.5 DS in cardiac surgery does not seem to be associated with a clinically significant deterioration of postoperative renal function

Impact of 6 % hydroxyethyl starch (HES) 130/0.4 on the correlation between standard laboratory tests and thromboelastography (TEG(R)) after cardiopulmonary bypass.

BACKGROUND: Hydroxyethyl starches (HES) affect the results of thromboelastography (TEG(R)). We sought to determine whether using HES rather than crystalloids for cardiopulmonary bypass (CPB) prime and intraoperative fluid therapy changes the TEG cutoff values best identifying patients with a low platelet count or a low fibrinogen level after CPB. METHODS: Data from 96 patients who had on-pump cardiac surgery, a TEG(R) (kaolin-heparinase) and standard investigations of blood clotting performed after separation from CPB and protamine administration were retrospectively reviewed. Patients were assigned to the HES or crystalloid group according to whether balanced 6% HES 130/0.4 or balanced crystalloids were used for intraoperative fluid therapy and pump prime. Mutlivariable linear regression models with computation of the standardized regression coefficients were used to identify independent associations between the four main TEG parameters (R time, alpha angle, K time and MA) and the type of fluid used, the INR, the aPTT, the fibrinogen level and the platelet count. Receiver-operating-characteristic curves were used to assess the effect of HES on the ability of TEG parameters to identify patients with a platelet count<80.000mul(-1) or a fibrinogen level<1.5 gr l(-1) and on the cutoff values best identifying these patients. RESULTS: The type of fluid used significantly affected the MA (P<0.001), the K time (P<0.001) and the alpha angle (P<0.001) regardless of the results of the standard clotting tests. According to standardized ss regression coefficients the platelet count and the type of fluid used were stronger predictors of the MA, the alpha angle and the K time than the fibrinogen level. MA better predicted platelets<80.000mul(-1) than K time and alpha angle (P=0.023). The best cutoff value of MA identifying patients with platelets<80.000mul(-1) was 62mm in the crystalloid group and 53mm in the HES group. MA, K time and alpha angle were poor predictors of the postoperative fibrinogen level. CONCLUSION: HES significantly changes the cutoff value of TEG(R) MA best identifying patients<80.000mul(-1) after on-pump cardiac surgery