Surfactant Adsorption Layers: Experiments and Modeling.

During recent years, great progress has been made in understanding the adsorption of surfactants at liquid interfaces. In addition to tensiometry, new efficient methodologies have been developed, in particular interfacial selective optical methods which allow direct access to the adsorbed amounts and interfacial layer compositions. In addition to these new experimental tools, the thermodynamic description by equations of state now allows one to provide a quantitative picture of surfactant interfacial layers. This is most notable for surfactant layers at water/oil interfaces. Additional knowledge about the structure of interfacial layers was gained through different types of molecular modeling. Improved interrelationships between these three aspects are the challenges for current and future work. Particular attention must be paid to dilational interfacial rheology studies, as these mechanical quantities are much more sensitive to small changes in the interfacial composition and structure.

[Prehospital management of acute coronary syndrome in patients on long-term direct oral anticoagulant treatment]. / Prähospitale Behandlung des akuten Koronarsyndroms unter DOAK-Dauertherapie.

BACKGROUND: Despite an increasing incidence of patients suffering from acute coronary syndrome (ACS) under simultaneous treatment with direct oral anticoagulants (DOAC), neither sufficient scientific data nor uniform guidelines for the anticoagulation treatment of these patients are currently available. OBJECTIVE: The aim of this study was to determine the current practice of preclinical treatment of ACS in patients under DOAC treatment. MATERIAL AND METHODS: An internet and paper-based survey of emergency physicians, specialists of internal medicine, anesthesiologists, emergency and intensive care physicians was performed concerning the prehospital treatment of ACS in patients under long-term DOAC treatment. RESULTS: Overall, 284 questionnaires were answered. Substantial differences in the current treatment of ACS under long-term DOAC therapy were identified. While 39% of the respondents stated that they administer a combination treatment of heparin and acetylsalicylic acid (ASA), 36% renounced the administration of heparin. If a dose reduction was performed, 71% answered that they reduce the heparin dosage. Also, in cases of ST-segment elevation myocardial infarction 48% of the physicians renounced the administration of heparin. CONCLUSION: In Germany there is currently a heterogeneous practice of emergency treatment of ACS patients under DOAC therapy with respect to the administration of heparin and ASA. Therefore, guidelines of the specialist medical societies should address the prehospital emergency anticoagulation management of ACS in patients under therapy with DOAC, which correspond to the needs of patients and emergency physicians.

Intra-abdominal sepsis: new definitions and current clinical standards.

PURPOSE: The abdomen is the second most common source of sepsis and is associated with unacceptably high morbidity and mortality. Recently, the essential definitions of sepsis and septic shock were updated (Third International Consensus Definitions for Sepsis and Septic Shock, Sepsis-3) and modified. The purpose of this review is to provide an overview of the changes introduced by Sepsis-3 and the current state of the art regarding the treatment of abdominal sepsis. RESULTS: While Sepsis-1/2 focused on detecting systemic inflammation as a response to infection, Sepsis-3 defines sepsis as a life-threatening organ dysfunction caused by a dysregulated host response to infection. The Surviving Sepsis Campaign (SSC) guideline, which was updated in 2016, recommends rapid diagnosis and initiating standardized therapy. New diagnostic tools, the establishment of antibiotic stewardship programs, and a host of new-generation antibiotics are new landmark changes in the sepsis literature of the last few years. Although the "old" surgical source control consisting of debridement, removal of infected devices, drainage of purulent cavities, and decompression of the abdominal cavity is the gold standard of surgical care, the timing of gastrointestinal reconstruction and closure of the abdominal cavity ("damage control surgery") are discussed intensively in the literature. The SSC guidelines provide evidence-based sepsis therapy. Nevertheless, treating critically ill intensive care patients requires individualized, continuous daily re-evaluation and flexible therapeutic strategies, which can be best discussed in the interdisciplinary rounds of experienced surgeons and intensive care medicals.

Sepsis-induced long-term immune paralysis--results of a descriptive, explorative study.

BACKGROUND: Long-lasting impairment of the immune system is believed to be the underlying reason for delayed deaths after surviving sepsis. We tested the hypothesis of persisting changes to the immune system in survivors of sepsis for the first time. METHODS: In our prospective, cross-sectional pilot study, eight former patients who survived catecholamine-dependent sepsis and eight control individuals matched for age, sex, diabetes and renal insufficiency were enrolled. Each participant completed a questionnaire concerning morbidities, medications and infection history. Peripheral blood was collected for determination of i) immune cell subsets (CD4(+), CD8(+) T cells; CD25(+) CD127(-) regulatory T cells; CD14(+) monocytes), ii) cell surface receptor expression (PD-1, BTLA, TLR2, TLR4, TLR5, Dectin-1, PD-1 L), iii) HLA-DR expression, and iv) cytokine secretion (IL-6, IL10, TNF-α, IFN-γ) of whole blood stimulated with either α-CD3/28, LPS or zymosan. RESULTS: After surviving sepsis, former patients presented with increased numbers of clinical apparent infections, including those typically associated with an impaired immune system. Standard inflammatory markers indicated a low-level inflammatory situation in former sepsis patients. CD8(+) cell surface receptor as well as monocytic HLA-DR density measurements showed no major differences between the groups, while CD4(+) T cells tended towards two opposed mechanisms of negative immune cell regulation via PD-1 and BTLA. Moreover, the post-sepsis group showed alterations in monocyte surface expression of distinct pattern recognition receptors; most pronouncedly seen in a decrease of TLR5 expression. Cytokine secretion in response to important activators of both the innate (LPS, zymosan) and the adaptive immune system (α-CD3/28) seemed to be weakened in former septic patients. CONCLUSIONS: Cytokine secretion as a reaction to different activators of the immune system seemed to be comprehensively impaired in survivors of sepsis. Among others, this could be based on trends in the downregulation of distinct cell surface receptors. Based on our results, the conduct of larger validation studies seems feasible, aiming to characterize alterations and to find potential therapeutic targets to engage.

Impact of unsuspected subsegmental pulmonary embolism in ICU patients.

BACKGROUND: Critically ill patients in intensive-care units are at high risk for pulmonary embolism (PE). As a result of modern multi-detector computed tomographic angiography (MDCT) increased visualization of peripheral pulmonary arteries, isolated subsegmental pulmonary embolisms (ISSPE) are increasingly being detected. AIM: The aim of this study was to investigate the rate, impact on treatment, and outcome of unsuspected ISSPE in critically ill patients receiving MDCT. The secondary aim was to investigate the potential impact of contrast media-induced nephropathy (CIN) in our cohort. METHODS: We conducted a retrospective single-centre analysis on critically ill adult patients treated between January 2009 and December 2012 who underwent a contrast-enhanced chest MDCT. We excluded patients with clinical suspicion of PE/ISSPE prior to CT and patients with MDCT confirmed central PE. Clinical findings, laboratory parameters, and outcome data were recorded. RESULTS: We identified 240 ICU patients not suspected for PE receiving MDCT. A total of 12 Patients (5%) showed unexpected ISSPE representing increased 24 h mortality (16.7 vs. 3.5%; p = 0.026) compared to non-ISPPE/non-PE patients. A 30-days mortality did not differ between the groups (33.3 vs. 33.8%; p = 0.53). Highest mean creatinine serum level in our cohort (n = 240) was found before MDCT with a significant decrease to day 5 (1.4 ± 1.1 vs. 1.1 ± 0.9 mg/dl: p < 0.0001) after contrast media administration. CONCLUSION: Critically ill patients are at relevant risk for ISSPE. ISSPE was associated with a poor 24 h outcome. In addition, in our cohort, contrast media application was not associated with increased serum creatinine.

[Patient with a Fontan circulation undergoing caesarean section: Anesthesiological management]. / Sectio caesarea bei einer Patientin mit Fontan-Zirkulation : Anästhesiologisches Management.

Adults suffering from congenital heart diseases (CHD) represent a challenge to anesthesiologists because of the diverse pathologies, complex pathophysiology and special treatment strategies. Due to improved therapeutic options for CHD, patient quality of life and life expectancy is increasing, leaving them as a growing population including pregnant patients with CHD. This article presents the main principles of the pathophysiology and anesthesiological management of pregnant patients living with a Fontan circulation based on a case report, which was complicated by an aortic coarctation and atonic uterine hemorrhage.

[Anesthesiological management of Gitelman syndrome : Teaching example on physiology and pathophysiology of electrolyte balance]. / Anästhesiologisches Management des Gitelman-Syndroms : Lehrbeispiel zur Physio- und Pathophysiologie des Elektrolythaushalts.

Gitelman syndrome is a rare autosomal recessive inherited disease that affects the thiazide-sensitive sodium chloride cotransport channels and the magnesium channels of the distal renal tubuli. Characteristic features are hypokalemia, hypomagnesemia, metabolic alkalosis and hypocalciuria. This case report presents the anesthesiological management of the Gitelman syndrome. The article demonstrates the pathophysiology, symptoms, diagnosis and therapy of this disease from the anesthesiologists point of view.

New view of the adsorption of surfactants at water/alkane interfaces - Competitive and cooperative effects of surfactant and alkane molecules.

The theoretical description of the adsorption of surfactants at interfaces between aqueous solutions and oil was based over a very long time on models derived for the solution/air interface. Thus, most of the experimentally observed peculiarities could not be specifically considered but were merely interpreted in terms of a penetration of oil molecules into the alkyl chain layer of the adsorbed surfactant molecules. These penetrating oil molecules enhance the surfactant adsorption as compared to the water/air interface. Later on, for the special situations at water/oil interfaces a competitive adsorption of surfactant and oil molecules was postulated, allowing a much better description of experimental data. This picture, however, was unable to explain why the interfacial tension of the water/oil interface decreases very quickly when extremely small amounts of surfactants are added to the water. This effect cannot be of competitive nature, but a cooperativity of surfactant and oil molecules forming a mixed adsorption layer is required instead. This cooperative effect means that already few surfactant molecules adsorbed at the interface can induce a significant ordering of oil molecules in the interfacial layer. This new interfacial structure, in turn, attracts further surfactant molecules to adsorb. Improving the theoretical description of experimental data was finally achieved by applying suitable adsorption models for the two adsorbing compounds, i.e. a Frumkin adsorption model for the oil molecules and a Langmuir, Frumkin, or reorientation model for the adsorbing surfactant molecules. Here, the progress in modelling surfactant adsorption at water/oil interfaces is discussed mainly for the homologous series of the cationic surfactants CnTAB, of the anionic surfactant SDS, and members of the homologous series of the non-ionic surfactants CnDMPO at water/alkane interfaces.

The impact of early surgical intervention in free intestinal perforation: a time-to-intervention pilot study.

PURPOSES: An abdominal inflammatory focus is the second most often source of sepsis with a high risk of death in surgical intensive care units. By establishing evidence-based bundled strategies the surviving sepsis campaign provided an optimized rapid and continuous treatment of these emergency patients. Hereby the hospital mortality decreased from 35 to 30 %. Sepsis treatment is based on three major therapeutic elements: surgical treatment (source control), antiinfective treatment, and supportive care. The international guidelines of the surviving sepsis campaign were updated recently and recommend rapid diagnosis of the infection and source control within the first 12 h after the diagnosis (grade 1c). Interestingly this recommendation is mainly based on studies on soft tissue infections. METHODS: In this retrospective analysis 76 septic patients with an intraabdominal inflammatory focus were included. All patients underwent surgery at different time-points after diagnosis. RESULTS: With 80 % patients of the early intervention group had an improved overall survival (vs. 73 % in the late intervention group). CONCLUSIONS: Literature on the time dependency of early source control is rare and in part contradicting. Results of this pilot study reveal that immediate surgical intervention might be of advantage for septic emergency patients. Further multi-center approaches will be necessary to evaluate, whether the TTI has any impact on the outcome of septic patients with intestinal perforation.

[Diagnosis and therapy of an acute abdomen]. / Diagnostik und Therapie des akuten Abdomens.

Patients with signs of an acute abdomen continue to be a challenge for both the emergency physician and the intensivist. Clinical symptoms usually result from secondary peritonitis possibly progressing to intraabdominal sepsis. Critically ill patients need rapid diagnostic work-up and an interdisciplinary therapeutic approach. Among patients with secondary peritonitis, those with postoperative peritonitis (e.g., after anastomotic leakage) show a particularly high mortality because of unspecific symptoms. Beyond routine diagnostic procedures, patients with an acute abdomen often require a CT scan which helps to detect the septic focus, thereby often allowing an interventional source control. Therapy consists of three main elements: source control, broad-spectrum antimicrobial therapy, and supportive intensive care medicine.