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Objective:The purpose of this study was to investigate the effect of hypertonic (NaCl 7.5%) hydroxyethyl starch (HES 6%, molecular weight 200,000) (HHES) as used for small-volume resuscitation on global coagulation parameters and platelet function. Design:Randomized, controlled clinical trial. Setting:Intraoperative volume loading after induction of general anesthesia. Patients:27 consecutive patients [mean age 59 (22-76) years, mean body weight 69.8 (46-98) kg] undergoing abdominal surgery were studied. Interventions:Global coagulation tests (aPTT: activated partial thromboplastin time; PT: prothrombin time; platelet count; thrombelastography: TEG), platelet aggregation and ATP release were measured before and 10 min after the application of 4 ml•kg-1 of HHES (study group H, n = 14) or HES (control group C, n = 13). Results:The aPTT was prolonged and platelet count was significantly reduced in both study groups. In contrast to the HES group, clot formation time in the TEG was significantly prolonged and the maximum amplitude was reduced in the HHES group. Furthermore, platelet aggregation was significantly slowed down, whereas ATP release significantly increased in the HHES group. Conclusion:The changes in global coagulation parameters can be explained by dilu-tional effects of the infused solution. The hyperosmolar saline compound of the HHES solution obviously contributes to the slowing down of platelet aggregation. Osmotic stress and membrane pleating may aggravate HES-induced changes in membrane fluidity and microviscosity and thus explain this impaired interaction. The increase in ATP release suggests a change in receptor – second messenger interaction for δ granule release.

Das Ziel dieser Studie war die Entwicklung eines spezifischen Schweregradklassifizierungssystems für die Beurteilung und Vorhersage von Organfunktionsstörungen und Überleben bei herzchirurgischen Intensivpatienten. Hierzu wurden konsekutiv alle erwachsenen Patienten nach einem herzchirurgischen Eingriff unter Einsatz der Herzlungenmaschine über einen Zeitraum von 3 Jahren in die Studie aufgenommen. Im Konstruktionsset erfolgte die Auswahl der Variablen mit Hilfe der Patienten, die mindestens 24 Stunden auf der Intensivstation verbrachten. Die Ergebnisse wurden dann in zwei Validierungssets mit allen Intensivpatienten überprüft. Die Qualität des Scores wurde mit dem Hosmer-Lemeshow-Test (HL) sowie der ROC-Analyse beurteilt, und mit dem APACHE-II- und dem MODS-Score verglichen. Insgesamt wurden 3230 Patienten über einen Zeitraum von 3 Jahren auf unserer Intensivstation aufgenommen. Die HL-Werte für den neuen Score waren 5,8 (APACHE-II: 11,3; MODS: 9,7) für das Konstruktionsset, 7,2 (APACHE-II: 8,0; MODS: 4,5) für das Validierungsset I und 5,9 für das Validierungsset II. Die Fläche unter der ROC-Kurve war 0,91 (APACHE-II: 0,86; MODS: 0,84) für den neuen Score im Konstruktionsset, 0,88 (APACHE-II: 0,84; MODS: 0,84) in dem Validierungsset I, und 0,92 in dem Validierungsset II. Der neue CASUS (Cardiac Surgery Score) zeigt für herzchirurgische Intensivpatienten eine exzellente Kalibrierung und Diskriminierung bezüglich der 30-Tage-Letalität. Die Variablen des CASUS sind einfach, reproduzierbar und werden routinemäßig in herzchirurgischen Intensivstationen erfasst. Der CASUS könnte als Expertensystem für das Diagnostizieren von Organfunktionsstörungen, der Entscheidungsfindung, der Ressourcenauswertung und Vorhersage der Letalität für herzchirurgische Intensivpatienten dienen. The purpose of this study was to develop a specific postoperative score in intensive care unit (ICU) cardiac surgical patients for assessment of organ dysfunction and survival. This prospective study consisted of all consecutive adult patients admitted after cardiac surgery to our ICU over a period of 3 years. Evaluation of variables was performed using the first year patients who stayed in ICU for at least 24 hours. The reproducibility was then tested in two validation sets using all patients. Performance was assessed with the Hosmer-Leme-show (χ2-statistics) goodness-of-fit test and receiver operating characteristic (ROC) curves and compared with the APACHE II and MODS. A total of 3230 patients were admitted to the ICU after cardiac surgery. Mean χ2-values for the new score were 5.8 (APACHE II, 11.3; MODS, 9.7) for the construction set, 7.2 (APACHE II, 8.0; MODS, 4.5) for the validation set I and 5.9 for the validation set II. The mean area under the ROC curve was 0.91 (APACHE II, 0.86; MODS, 0.84) for the new score in the construction set, 0.88 (APACHE II, 0.84; MODS, 0.84) in the validation set I and 0.92 in the validation set II. Our new ten-variable risk index performs very well, with calibration and discrimination very high, better than general severity systems, and it is an appropriate tool for daily risk stratification in ICU cardiac surgery patients. Thus, it may serve as an Expert System for diagnosing organ failure, decision making, resource evaluation, and predicting mortality in ICU cardiac surgical patients.

SUMMARYIntroduction:Bleeding after heart operations remains a common complication and contributes to morbidity and death. Recent studies have suggested that antiplatelet therapy (APT) may not increase homologous blood requirements in coronary bypass surgery. The purpose of this study was to examine the influence of APT therapy on haemorrhage and transfusion requirements in patients undergoing coronary artery bypass (CABG) on cardiopulmonary bypass (CPB).Materials and methods:Records from 290 consecutive patients who underwent CABG with CPB were retrospectively reviewed, including 145 patients who received APT within 5 days prior to surgery and 145 control patients (CON). Blood loss was measured up to 24 h. Demographic and clinical patient data were collected until hospital discharge.Results:Both groups were well matched with respect to demographic and intra-operative data.There was significantly ( p< 0.0005) more mediastinal tube drainage at 24 h in the APT group (1123 mL ± 537 mL) compared to CON patients (874 mL ± 351 mL). In addition, the APT group received significantly more units of blood (APT: 2.6 ± 2.5 vs CON: 1.6 ± 1.8; p< 0.0005), platelet units (APT: 1.2 ± 1.8 vs CON: 0.2 ± 0.8; p< 0.0005), and fresh frozen plasma units (APT: 2.0 ± 2.2 vs CON: 1.3 ± 2.0; p 0.01).Conclusion:This study suggests consideration should be given to delaying elective CABG for patients who have received APT treatment until APT is discontinued for at least 5 days.

Zusammenfassung Wir berichten über eine 23-jährige Patientin, die sich nach kieferchirurgischer monomaxillärer Umstellungsosteotomie nun der Metallentfernung unterzog. Am Ende des operativen Eingriffs wurde die Anästhetikazufuhr beendet. Über einen Zeitraum von 30 min wurden mehrere erfolglose Aufwachversuche unternommen. Während der gesamten Zeit waren keine Veränderungen der Herzfrequenz oder des Blutdrucks, keine Rückkehr von Schutzreflexen (Husten, Schlucken, Pressen) sowie keine motorischen oder stressbedingten Reaktionen (Schwitzen, Tränenfluss, Mydriasis) festzustellen. Erst 30 min nach Operationsende wurde bei der Patientin ein Überhang von Mivacurium mit der Relaxometrie diagnostiziert. Es wurde eine intensivmedizinische Nachbeatmung für 9 h unter Sedierung durchgeführt. Als Ursache der verlängerten Relaxanzienwirkung wurde das Vorliegen einer atypischen Cholinesterase festgestellt. Die Patientin konnte sich nachträglich detailliert an die Ereignisse erinnern. Sie gab an, keine Angst oder Hilflosigkeit verspürt zu haben, da sie die Stimme der Anästhesistin die ganze Zeit über beruhigt habe. Die Anästhesistin war seit vielen Jahren eine enge Freundin der Familie der Patientin. In einem Gespräch einige Monate nach dem Ereignis gab die Patientin weder eine verstärkte Angst gegenüber operativen Eingriffen noch andere negative psychische Folgen auf ihr Leben an. Der beruhigende Einfluss der Anästhesistin hat verhindert, dass die Ereignisse für die Patientin zu einem traumatischen Erlebnis mit möglichen anhaltenden psychischen Folgen wurde.

Zusammenfassung Eingegangen wird auf mögliche Zusammenhänge zwischen Anästhesie und Entstehung oder Verstärkung eines Tinnitus. Während nach einer „lege artis“ ausgeführten Allgemeinanästhesie keine erhöhte Tinnitusinzidenz oder anhaltende Tinnitusverstärkung zu erwarten ist, besteht bei der Spinalanästhesie die zwar seltene, dann aber typische Möglichkeit eines meist passageren Tieftonhörverlustes mit einem damit verbundenen Tieftontinnitus. Beim Einsatz von Lokalanästhesika kommen—in aller Regel reversible—Hörstörungen und Tinnitus bei zentraler Intoxikation vor.

SummaryIntroduction: Aprotinin (AP) reduces blood loss and transfusions after cardiopulmonary bypass (CPB), but may sensitise patients and is expensive. Tranexamic acid (TA) has less side-effects, but data regarding its efficacy are controversial. The aim of our prospective, randomised, double-blind study was to compare the impact of AP vs. TA on drainage blood loss and transfusion requirements in patients undergoing first time CABG on CPB.Materials and Methods: One hundred and twenty adult patients were randomised to receive either high-dose AP according to Hammersmith or a total of 2 g TA. Perioperative blood products were transfused in a standardised fashion. Blood loss was measured up to 24 h. Demographic and clinical patient data were collected until hospital discharge.Results: The data from 118 patients (TA: n = 58, TA appears to be a cost-effective alternative to AP AP: n = 60) who completed the study according to protocol were analysed. Blood loss at 24 h postoperation in TA patients was significantly higher (896 ± 354 ml) as compared to AP patients (756 ± 347ml; p = 0.03). TA patients received 1.5 ± 1.5 units of red blood cells (AP: 1.5 ± 1.7, p = 1.0), 1.3 ± 2.0 units of fresh frozen plasma (AP: 1.0 ± 2.0, p = 0.38) and 0.5 ± 1.4 units of platelets (AP: 0.2 ± 0.7, p = 0.15). Clinical data, including perioperative myocardial infarction rate, acute renal failure, mechanical ventilation, hospital stay and mortality, were not significantly different between either group.Conclusion: Our data show a difference in blood loss between TA and high-dose AP. Although statistically significant, it has little clinical relevance, because perioperative transfusion requirements were similar for both groups. Thus, TA appears to be a cost-effective alternative to AP in primary CABG patients.

Intracranial misplacement of a tracheal tube during attempted nasotracheal intubation is a rare, usually lethal complication. Such incidents are associated with fractures of the face and base of the skull. We report inadvertent intracranial placement of a nasotracheal tube in a patient who had 2 weeks previously undergone transnasal trans-sphenoidal surgery for a pituitary tumour. One should be aware that transnasal trans-sphenoidal surgery leaves a bony defect in the skull, which is susceptible to perforation by nasally introduced tubes.

Abstract: Near-γ TiAl- and Al3Ti-based intermetallic matrix composites have been produced using in-situ reaction-synthesis techniques. The intermetallic matrices have been reinforced with relatively high loadings (e.g., 20 to 50 vol pct) of dispersed TiB2 particulates. It is shown that the as-synthesized TiB2 size is strongly dependent on the specific alloy formulation; specifically, the TiB2 size tends to increase as the nominal volume percent of TiB2 in the composite increases. The observed size effect is determined to be associated with the temperature that is attained during the synthesis event, which is established primarily by the net exothermicity of the participating synthesis reaction(s). The exothermicity of the reactions can be assessed through the calculation of a formulations’s adiabatic temperature, which is found to increase with the percentage of TiB2 over the range of approximately 10 to 60 vol pct. The coupling of a composite’s characteristic adiabatic temperature with the resulting reinforcement size provides direct links among composition, processing, and mechanical performance, since the size of a reinforcing particle is influential in establishing the interparticle spacing, which, in turn, establishes the strengthening potency of the dispersed phase within the composite.

Abstract: The deformation behavior under creep conditions of several unreinforced and participate (TiB2)-reinforced binary near-gamma titanium aluminide alloys has been examined. Material has been produced using both ingot-and powder-processing techniques, yielding material of varying microstructures and grain sizes. It has been found that the rate of deformation is strongly dependent on matrix grain size and microstructural stability. The presence of the dispersed phase dramatically impacts the microstructural character which evolves following isothermal forging, and this has been observed to strongly influence the creep behavior. Constitutive equations which describe the observed behavior indicate that the mechanism of creep deformation is the same for both the reinforced and unreinforced variants and is independent of processing route.

Abstract: Two binary titanium aluminide alloys, Ti-43A1 and Ti-47A1 (atomic percent), were discontinuously reinforced with 6 vol pct titanium diboride, resulting in a two-phase Ti3Al and TiAl (α2 and γ, respectively) matrix with a dispersion of TiB2 particulate. Cast material was successfully ex-truded and subjected to a series of single-step and duplex-step heat treatments. Thermo-mechanical processing was correlated with microstructural changes, and the ambient temperature mechanical properties were measured for the various heat-treated conditions using tensile and hardness testing. Yield stress and plastic elongation to failure and hardness were found to cor-relate well with the fraction of proeutectoid, or primary, TiAl formed during heat treatment within the α/γ phase field. Precipitation of y within proeutectoid α grains during subsequent aging treatments within the α2 phase field was seen to increase the room-temperature ductility with negligible debits in yield stress. Enhanced ductility and decreases in yield stress and hard-ness are associated with morphologically large regions of the TiAl phase. Incompatibility of slip systems across γ/α2 and the inherent resistance to slip in hyperstoichiometric Ti3Al are suggested as possible explanations for the observed phenomena.

A series of TiB2-reinforced near-γtitanium aluminide (Ti-Al) matrix composites have been produced in investment-cast form and characterized with respect to microstructure and tensile deformation. The Ti-Al matrices of the composites examined are based upon the binary composition Ti-47 Al (at. pct), with varying proportions (2 to 6 cumulative percent) of manganese, vanadium, chromium, and niobium. TiB2has been introduced into the microstructuresviaXD* processing at levels of 7 and 12 vol pct and compared to unreinforced (0 vol pct TiB2), base variants. The influences of heat-treatment temperature and time have also been studied for each composition and reinforcement variant. The addition of dispersed TiB2leads to a fine, stable, and homogeneous as-cast matrix microstructure. The measured TiB2size within the composites examined ranged from 1.4 to 2.6 µm. Increasing the volume fraction of TiB2leads to increased elastic moduli, increased ambient temperature tensile strengths, and in general, increased strain-hardening response. In some instances, the overall ductility of the alloy increases with the addition of TiB2reinforcement. The flow stresses of both the monolithic and composite variants exhibit conventional power-law plasticity. The results indicate that the strengthening and the flow behavior in these composites are derived from both indirect and direct sources. Strengthening contributions are indirectly derived from the microstructural changes within the matrix of the composite that evolve due to the presence of the reinforcement during its evolution and development, for example, due to grain refinement and reinforcement-derived interstitial solid-solution strengthening. Direct contributions to strength are those that can be specifically attributed to the presence of the reinforcement during deformation,e.g., through the interaction of dislocations with the reinforcing particles. When the estimates of the indirect contributions are isolated and arithmetically removed from the magnitude of the total observed strength of the composite, the increase in flow stress correlates in all instances with the inverse square root of the planar interparticle spacing for all alloy compositions, heat treatments, and levels of strain examined.

Abstract: The influence of erbium on the behavior of titanium and titanium-aluminum based alloys has been investigated over a range of strain rates and temperatures (25 to 775C). Data from hotextruded bulk specimens indicate that, although oxide dispersion strengthening can be large under certain conditions, the strengthening is minimal in fine-grain material subjected to low strain rate deformation at high temperatures. Both microstructural observations and an analysis of the flow data indicate profuse grain boundary sliding under these conditions. Grain coarsening anneals, which also coarsen the dispersoids and increase their population along grain boundaries, result in significantly improved high temperature flow strengths, especially in the high temperature/low strain rate regime.

Zusammenfassung: In unserer Klinik war Carbostesin 0,5% hyperbar (AstraZeneca) durch Bucain 0,5% hyperbar (Curasan) ausgetauscht und als pharmakologisch gleichwertig angeboten worden.Die beiden Lokalansthetika unterscheiden sich jedoch durch ihren Glukoseanteil. Wir berichten ber 3 Patientinnen, die eine Spinalansthesie zur Sectio caesarea erhielten. Bei 2 Patientinnen beobachteten wir nach Verwendung von Bucain 0,5% hyperbar eine nur unzureichende Ausbreitung der Spinalansthesie.Die dritte Patientin erhielt wieder die zuvor bliche Kombination von Carbostesin 0,5% hyperbar mit Fentanyl und zeigte einen unaufflligen Verlauf. Nach Durchsicht der Literatur msste die klinische Wirkung von Carbostesin 0,5% hyperbar und Bucain 0,5% hyperbar identisch sein. Es htte nicht zu einer kritischen Verdnnung des Bucains durch den Fentanylzusatz kommen drfen.