[Improvement in burn wound care: summary of the AWMF guideline for the treatment of thermal injuries in adults]. / Optimierung der chirurgischen Behandlung Brandverletzter: Auszüge aus der fachübergreifenden S2k-Leitlinie "Behandlung thermischer Verletzungen des Erwachsenen".

INTRODUCTION: More than half a million patients suffer from minor burns in Germany per year. In 2018, almost 2000 patients needed intensive care for their burn injuries. Despite high standards of burn care, mortality remains high. Burn injuries may lead to long-term sequelae. In order to provide up-to-date burn care, guidelines are available online with public access. METHODS AND RESULTS: This overview presents a summary of the German AWMF guideline for the treatment of thermal injuries in adults (https://www.awmf.org/leitlinien/detail/ll/044-001.html). Experts of eleven different medical organisations and specialties have contributed to this S2k guideline with their expertise. The focus of the article is on acute burn wound assessment, the indication for specialised care in burn centres, the management of the burn wound at the trauma scene and in hospitals as well as scar management and rehabilitation. CONCLUSION: This overview reports on the consensus-based treatment of acute burn wounds in adults in Germany. The article is intended to guide doctors and professional caretakers to perform state-of-the-art burn care. The current guideline aims to improve burn outcome.

Investigation of the Usability of Computerized Critical Care Information Systems in Germany.

INTRODUCTION: The term "usability" describes how effectively, efficiently, and with what level of user satisfaction an information system can be used to accomplish specific goals. Computerized critical care information systems (CCISs) with high usability increase quality of care and staff satisfaction, while reducing medication errors. Conversely, systems lacking usability can interrupt clinical workflow, facilitate errors, and increase charting time. The aim of this study was to investigate and compare usability across CCIS currently used in Germany. METHODS: In this study, German intensive care unit (ICU) nurses and physicians completed a specialized, previously validated, web-based questionnaire. The questionnaire assessed CCIS usability based on three rating models: an overall rating of the systems, a model rating technical usability, and a model rating task-specific usability. RESULTS: We analyzed results from 535 survey participants and compared eight different CCIS commonly used in Germany. Our results showed that usability strongly differs across the compared systems. The system ICUData had the best overall rating and technical usability, followed by the platforms ICM and MetaVision. The same three systems performed best in the rating of task-specific usability without significant differences between each other. Across all systems, overall ratings were more dependent on ease-of-use aspects than on aspects of utility/functionality, and the general scope of the functions offered was rated better than how well the functions are realized. DISCUSSION: Our results suggest that manufacturers should shift some of their effort away from the development of new features and focus more on improving the ease-of-use and quality of existing features.

Functional requirements of critical care information systems (CCIS) from the users' perspective.

INTRODUCTION: Critical care information systems (CCIS) are computer software systems specialized for supporting the data processing tasks of clinical staff in intensive care units (ICUs). Reports on the impact of CCIS vary strongly from large benefits to harmful impact. One factor causing these inconsistent results is a large functional heterogeneity of the currently available systems, as no standards exist. Therefore, the aim of this study was to derive recommendations for a minimum range of functions that CCIS should incorporate from the perspective of clinical users. MATERIALS AND METHODS: We performed a web-based survey targeting clinical ICU staff in Germany. Participants rated the usefulness of pre-defined CCIS functions (36 for physicians / 31 for nurses) between 0-5. To capture confounders that might influence the ratings, we recorded 18 individual and workplace characteristics. RESULTS: The 912 participants rated all but three of the investigated functions as useful with median scores of 4-5. A multivariable analysis showed that the ratings were influenced by whether CCIS were used on the participants' wards, by the rating of the function quality of the used CCIS, the years of work experience and whether the participant was a physician or a nurse. CONCLUSIONS: Clinical ICU staff considers all but three of the here investigated CCIS functions as useful. Even though we identified a variety of factors influencing the usefulness ratings, their influence is rather small and thus does not limit the validity of our findings. Accordingly, we commend the functions identified as useful to be incorporated in CCIS.

Effect of Clopidogrel on Thrombus Formation in an Ex Vivo Parallel Plate Flow Chamber Model Cannot Be Reversed by Addition of Platelet Concentrates or vWF Concentrate.

BACKGROUND: Hemorrhage is the most important complication of antithrombotic therapy with P2Y12 receptor blockers. The administration of platelet concentrates (PCs) and von Willebrand factor (vWF) concentrates are common procedures to normalize impaired primary hemostasis in bleeding patients. We tested whether this strategy reverses the effect of clopidogrel using a parallel plate flow chamber model. METHODS: Whole blood from patients, who received a loading dose of clopidogrel with 600 mg and an ongoing dual antiplatelet therapy with 75 mg/d clopidogrel and 100 mg/d acetyl salicylic acid, compared with blood from healthy volunteers was examined in a collagen-coated parallel plate flow chamber. Blood was perfused by suction at a shear rate of 300/s, which is equivalent to 14 dynes/cm to resemble shear stress in conduit arteries. Platelet-covered area, individual thrombus size, and the average thrombus size were assessed morphometrically. The equivalent of 2 or 5 units of PC and/or 2 U/mL of vWF concentrate were used in an attempt to restore coagulation capacity in blood samples of clopidogrel-treated patients. RESULTS: In this model, clopidogrel reduced the increase of thrombus size. The equivalent of 2 U of PC or 2 U/mL of vWF alone did not show any significant changes in thrombus size. 5 U of PC increased thrombus size in clopidogrel-treated patients (P < .05). Thrombus size in clopidogrel blood was increased by combined PC and vWF treatment (by 50%, P < .05), but this increase did not reach control levels (P < .05). CONCLUSIONS: This flow chamber model is suitable for detection of the antiplatelet effect of clopidogrel. Ex vivo addition of PC or vWF does not overcome the effects of clopidogrel in this model, but the combination of both shows a mild and significant improvement in thrombus size.

Design and validation of a questionnaire to evaluate the usability of computerized critical care information systems.

The implementation of computerized critical care information systems (CCIS) can improve the quality of clinical care and staff satisfaction, but also holds risks of disrupting the workflow with consecutive negative impacts. The usability of CCIS is one of the key factors determining their benefits and weaknesses. However, no tailored instrument exists to measure the usability of such systems. Therefore, the aim of this study was to design and validate a questionnaire that measures the usability of CCIS. Following a mixed-method design approach, we developed a questionnaire comprising two evaluation models to assess the usability of CCIS: (1) the task-specific model rates the usability individually for several tasks which CCIS could support and which we derived by analyzing work processes in the ICU; (2) the characteristic-specific model rates the different aspects of the usability, as defined by the international standard "ergonomics of human-system interaction". We tested validity and reliability of the digital version of the questionnaire in a sample population. In the sample population of 535 participants both usability evaluation models showed a strong correlation with the overall rating of the system (multiple correlation coefficients ≥0.80) as well as a very high internal consistency (Cronbach's alpha ≥0.93). The novel questionnaire is a valid and reliable instrument to measure the usability of CCIS and can be used to study the influence of the usability on their implementation benefits and weaknesses.

[Management of brain death organ donor]. / Management von Organspendern und Organempfängern - Spenderkonditionierung und Management der Organentnahme.

The demand for donor organs continues to exceed the number of organs available for transplantation. The assistance to the family members of a potential donor in forefront of transplantation is as much important as to maintain donor organ function. Caring for a brain dead potential organ donor is therefore major challenge for nurses and physicians.The pathophysiological changes following brain death entail a high incidence of complications including hemodynamic instability, endocrine and metabolic disturbances, that jeopardize potentially transplantable organs. The knowledge of the complex physiologic changes is crucial to the development of effective donor management strategies.The management of potential organ donors is similar to the management of patients with severe sepsis. The main goal of that treatment is to achieve hemodynamic stability as well as the normalization of endocrine and metabolic disturbances. Donor optimization leads to increased organ procurement and contributes to improved organ function in the recipient.

Mechano-chemical signaling in F9 cells.

We investigated the molecular mechanism by which cells recognize and respond to physical forces in their local environment. Using a model system, to study wild type mouse F9 embryonic carcinoma cells, we examined how these cells sense mechanical stresses and translate them into biochemical responses through their cell surface receptor integrin and via the focal adhesion complex (FAC). Based on studies that show that many signal transducing molecules are immobilized on the cytoskeleton at the site of integrin binding within the focal adhesion complex, we found a time-dependent increase of focal adhesion kinase (pp125(FAK)) phosphorylation possibly due to protein kinase C (PKC) activation as well as protein kinase A (PKA) activity increase upon cell adhesion/spreading. These studies provide some insight into intracellular mechano-chemical signaling.

The impact of endotracheal suctioning on gas exchange and hemodynamics during lung-protective ventilation in acute respiratory distress syndrome.

OBJECTIVE: To evaluate the respiratory and hemodynamic effects of open suctioning (OS) versus closed suctioning (CS) during pressure-control (PC) and volume-control (VC) ventilation, using a lung-protective ventilation strategy in an animal model of acute respiratory distress syndrome (ARDS). SETTING: Animal laboratory in a university hospital. DESIGN: Randomized cross-over evaluation. ANIMALS: Eight female Dorset sheep. INTERVENTIONS: Lung lavage was used to simulate ARDS. We applied VC and PC mechanical ventilation with a tidal volume of 6 mL/kg and positive end-expiratory pressure (PEEP), adjusted based on a table of PEEP versus fraction of inspired oxygen (FIO2). Suctioning was performed for 10 s with a suction pressure of -100 mm Hg, during both OS and CS. OS and CS were randomly performed with each animal. Hemodynamics and arterial blood gases were recorded before, during, and after endotracheal suctioning. RESULTS: The PaO2/FIO2 ratios before suctioning were similar in all groups, as were the PEEP and FIO2. PaO2/FIO2 was lower after OS than after CS/VC or CS/PC. There was no post-suctioning difference in oxygenation between CS/VC and CS/PC. PaCO2 recorded 10 min after suctioning was greater than the presuctioning value, in all groups. Intrapulmonary shunt fraction increased between baseline and 10 min post-suctioning with OS and CS/VC, but did not significantly increase with CS/PC. There were no significant changes in hemodynamics pre-suctioning versus post-suctioning with OS, CS/VC, or CS/PC. CONCLUSION: PaO2/FIO2) was better maintained during CS with both VC and PC modes during lung-protective ventilation for ARDS, as compared with OS, and shunt fraction post-suctioning changed least with PC.

Peak volume history and peak pressure-volume curve pressures independently affect the shape of the pressure-volume curve of the respiratory system.

OBJECTIVE: To determine the specific effect of peak volume history pressure on the inflation limb of the pressure-volume curve and peak pressure-volume curve pressure on the deflation limb of the pressure-volume curve. DESIGN: Prospective assessment of pressure-volume curves in saline, lung lavage injured sheep. SETTING: Large animal laboratory of a university-affiliated hospital. SUBJECTS: Eight female Dorset sheep. INTERVENTIONS: : The effect of two volume history pressures (40 and 60 cm H2O) and three pressure-volume curve peak pressures (40, 50, and 60 cm H2O) were randomly compared. MEASUREMENTS AND MAIN RESULTS: Peak volume history pressure affected the inflation curve beyond the lower inflection point but did not affect the inflection point (Pflex). Peak pressure-volume curve pressure affected the deflation curve. Increased peak volume history pressure increased inflation compliance (p <.05). Increased peak pressure-volume curve pressure increased the point of maximum compliance change on the deflation limb and deflation compliance and decreased compliance between peak pressure and the point of maximum curvature on the deflation limb (p <.05). CONCLUSION: Peak volume history pressure must be considered when interpreting the inflation limb of the pressure-volume curve of the respiratory system beyond the inflection point. The peak pressure achieved during the pressure-volume curve is important during interpretation of deflation compliance and the point of maximum compliance change on the deflation limb.

Open-lung protective ventilation with pressure control ventilation, high-frequency oscillation, and intratracheal pulmonary ventilation results in similar gas exchange, hemodynamics, and lung mechanics.

BACKGROUND: Pressure control ventilation (PCV), high-frequency oscillation (HFO), and intratracheal pulmonary ventilation (ITPV) may all be used to provide lung protective ventilation in acute respiratory distress syndrome, but the specific approach that is optimal remains controversial. METHODS: Saline lavage was used to produce acute respiratory distress syndrome in 21 sheep randomly assigned to receive PCV, HFO, or ITPV as follows: positive end-expiratory pressure (PCV and ITPV) and mean airway pressure (HFO) were set in a pressure-decreasing manner after lung recruitment that achieved a ratio of Pao2/Fio2 > 400 mmHg. Respiratory rates were 30 breaths/min, 120 breaths/min, and 8 Hz, respectively, for PCV, ITPV, and HFO. Eucapnia was targeted with peak carinal pressure of no more than 35 cm H2O. Animals were then ventilated for 4 h. RESULTS: There were no differences among groups in gas exchange, lung mechanics, or hemodynamics. Tidal volume (PCV, 8.9 +/- 2.1 ml/kg; ITPV, 2.7 +/- 0.8 ml/kg; HFO, approximately 2.0 ml/kg) and peak carinal pressure (PCV, 30.6 +/- 2.6 cm H2O; ITPV, 22.3 +/- 4.8 cm H2O; HFO, approximately 24.3 cm H2O) were higher in PCV. Pilot histologic data showed greater interstitial hemorrhage and alveolar septal expansion in PCV than in HFO or ITPV. CONCLUSION: These data indicate that HFO, ITPV, and PCV when applied with an open-lung protective ventilatory strategy results in the same gas exchange, lung mechanics, and hemodynamic response, but pilot data indicate that lung injury may be greater with PCV.

Determinants of tidal volume during high-frequency oscillation.

OBJECTIVE: High-frequency oscillation has been proposed for use in adult acute respiratory distress syndrome. However, limited data are available on the effect of pressure amplitude and rate (Hz) on tidal volumes delivered during high-frequency oscillation in adults. DESIGN: Prospective, animal model, lung injury study. SETTING: Large-animal laboratory of a university-affiliated medical center. SUBJECTS: Nine sheep (29.2 +/- 2.4 kg). INTERVENTIONS: Severe lung injury was induced by repeated saline lung lavage. After stabilization, high-frequency oscillation was initiated at a mean airway pressure equal to the point of maximum curvature on the deflation limb of the pressure-volume curve (26 +/- 1.9 cm H2O). Tidal volume at all combinations of rates of 4, 6, 8, and 10 Hz, pressure amplitudes of 30, 40, 50, and 60 cm H2O, and inspiratory/expiratory ratios of 1:1 and 1:2 (using the Sensormedics 3100B oscillator) were measured. Flow was measured by a pneumotachometer, amplified and digitized at 1000 Hz. Three breaths were analyzed at each setting. MEASUREMENTS AND MAIN RESULTS: At both inspiratory/expiratory ratios, tidal volume was directly proportional to pressure amplitude and inversely proportional to frequency. During an inspiratory/expiratory ratio of 1:1, at 60 cm H2O pressure amplitude and 4 Hz, a tidal volume of 129.1 +/- 34.8 mL (4.4 +/- 1.2 mL/kg) was delivered. CONCLUSIONS: At low rates and high-pressure amplitudes in this model, tidal volumes approaching conventional mechanical ventilation can be delivered during high-frequency oscillation.