Der Anaesthesist
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Healthy vascular endothelium is luminally coated by an endothelial glycocalyx, which interacts with the bloodstream and assumes a filter function on the vascular wall. Although this structure was discovered nearly 70 years ago, its physiological importance has been underestimated for a long time. Recent findings indicate that the glycocalyx is, in addition to the endothelial cells themselves, a main constituent part of the vascular barrier. ⋯ The endothelial glycocalyx, as an additional competent vascular permeability barrier has, therefore, not only a key role for perioperative fluid and protein shifts into the interstitial space, but it seems to be intimately involved in the pathophysiology of diabetes, arteriosclerosis, sepsis and ischemia/reperfusion, especially with respect to associated vascular dysfunctions. The fragile glycocalyx can be destroyed in the course of surgery, trauma, ischemia/reperfusion and sepsis and by inflammatory mediators such as TNF-alpha, causing leukocyte adhesion, platelet aggregation and edema formation. Recent studies have shown that protecting this structure not only maintains the vascular barrier, but constitutes an important component of a rational perioperative fluid therapy.
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Review
[Neurally adjusted ventilatory assist (NAVA). A new mode of assisted mechanical ventilation].
The aim of mechanical ventilation is to assure gas exchange while efficiently unloading the respiratory muscles and mechanical ventilation is an integral part of the care of patients with acute respiratory failure. Modern lung protective strategies of mechanical ventilation include low-tidal-volume ventilation and the continuation of spontaneous breathing which has been shown to be beneficial in reducing atelectasis and improving oxygenation. Poor patient-ventilator interaction is a major issue during conventional assisted ventilation. ⋯ First experimental studies showed an improved patient-ventilator synchrony and an efficient unloading of the respiratory muscles. Future clinical studies will have to show that NAVA is of clinical advantage when compared to conventional modes of assisted mechanical ventilation. This review characterizes NAVA according to current publications on this topic.
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Preoperative fasting aims at minimizing the risk of pulmonary aspiration. However, perioperative safety does not directly increase with the duration of total abstinence from food and liquids. The traditional principle "nil per os from midnight on", is based on insufficient data, overinterpretation and expert opinion. ⋯ This lack of knowledge is reflected by national and international guidelines concerning preoperative fasting, which mention the "patient at risk" without defining it exactly. Abstention from clear liquids 2 h before and of solids 6 h before induction of anesthesia, is becoming increasingly more accepted. Feeding babies with breast milk appears to be tolerated 4 h before anesthesiological procedures.
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Severe burn injuries are rare and represent less than 1% of all medical emergencies. At the scene of the accident self-protection is important. The progress of thermal injury should be stopped, while cold water therapy is usually not indicated as the resulting hypothermia severely reduces the prognosis. ⋯ Local or systemic administration of corticosteroids is not indicated. Transfer to a specialized burn unit depends on burn size and depth. Emergency room management includes stabilization of vital functions, evaluation of co-injuries and initiation of the specific surgical and intensive care therapy.
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Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in critical care medicine and has been shown to be an independent risk factor for mortality. However, ventilator induced lung injury itself is probably only a minor factor predisposing to VAP. In contrast, invasive ventilation using an endotracheal tube is obviously a more important measure. ⋯ Effectiveness of therapy depends on early treatment and therefore requires early diagnosis. With this aim combined clinical, radiologic, and microbiological parameters should be taken into account. Adequate antimicrobial therapy in due consideration for individual risk factors and local antibiotic resistance is the most important therapeutic measure.