Der Anaesthesist
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Dexmedetomidine is a highly selective, potent α₂-adrenoceptor agonist which was approved in 2011 by the European Medicines Agency for sedation of patients in intensive care units (ICU). Dexmedetomidine exhibits sedative as well as analgesic and anxiolytic effects. ⋯ This review summarizes the pharmacokinetics and pharmacodynamics of dexmedetomidine particularly in ICU patients and with special regard to covariate effects. Although dexmedetomidine is currently approved only for use in adults the pharmacokinetics and pharmacodynamics in children will also be addressed as there are numerous studies on this off-label use.
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Comparative Study Clinical Trial
[Transcutaneous carbon dioxide measurements. Dynamics during hyperventilation in healthy adults].
In various fields of medicine the transcutaneous measurement (p(tc)CO₂) of carbon dioxide pressure (pCO₂) has been accepted as a reliable measuring method while for other disciplines the method has been doubted. Nevertheless, some minor therapeutic interventions, such as electroconvulsive therapy and breathing biofeedback used in psychiatry could benefit considerably from transcutaneous monitoring. The study presented here investigated the accuracy of transcutaneous measurement as compared to end-tidal (p(et)CO₂) and capillary (p(cap)CO₂) measurements in hyperventilation. ⋯ In the presented hyperventilation experiment the agreement between the p(tc)CO₂ values and the p(et)CO₂ and p(cap)CO₂ measurements were comparable to the agreement between the latter two. Altogether, the comparability of the measurement methods seemed satisfactory. The delay between the time courses of p(et)CO₂ and p(tc)CO₂ of <1 min for most participants was short and is acceptable for clinical practice. Because only healthy subjects were tested these results might not be the same in children and critically ill patients and could differ from the presented results.
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Case Reports
[Functional separation of the lungs. Ventilation strategy for unilateral blunt force thoracic trauma].
Independent lung ventilation was performed in a patient with severe hypoxemia (oxygenation ratio p(a)O₂/F(I)O₂ 61 mmHg) due to unilateral blunt chest trauma and consecutive consolidation of the injured lung. Recruitment and immobilization of the consolidated lung was achieved by functional separation of both lungs with application of a mean airway pressure (p(mean)) of 28 mbar in combination with low frequency ventilation (4/min) of the injured lung. Adequate ventilation was maintained via the normal lung (p(mean) 14 mbar). This ventilation strategy stabilized oxygenation and ventilation by preventing overinflation and ventilator-induced lung injury.
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Review Historical Article
[Video laryngoscopy olé! Time to say good bye to direct and flexible intubation?].
A number of video laryngoscopy systems have been introduced into anesthetic practice in recent years. Due to the technical concepts of these systems exposure of the laryngeal structures is usually better than with direct laryngoscopy, both in normal airways as well as in those that are difficult to manage. With the increasing use of video laryngoscopy it seems as if direct laryngoscopy and flexible fibrescopic intubation are at risk of becoming redundant. This article describes current developments and discusses why expertise in direct laryngoscopy and flexible fibrescopic intubation should be maintained, particularly by experts in airway management.
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The second part of this overview focuses on how to assess more complex metabolic causes of acid-base imbalance. This is precisely the battlefield where most of the fiery debates between the Copenhagen, the Boston and the Stewart schools aroused. ⋯ With the Stewart diagnostic approach in mind the practitioner might wish considering therapeutic options that differ from what is suggested by the more traditional approaches. The specific diagnostic steps are integrated into a simplified algorithm and an acid-base calculator is provided.