Critical care : the official journal of the Critical Care Forum
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Whether the hydrogen sulfide (H2S)-induced metabolic depression observed in awake rodents exists in larger species is controversial. Therefore, Derwall and colleagues exposed anesthetized and ventilated sheep to incremental H2S concentrations by means of an extracorporeal membrane oxygenator. ⋯ The authors concluded that, beyond the effect of temperature, H2S hardly modifies metabolism at all. Since the highest H2S concentration caused toxic side effects (possibly due to an inhibition of mitochondrial respiration), the therapeutic use of inhaled H2S should be cautioned.
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Editorial Comment
Whole blood thromboelastometry: another Knight at the Roundtable?
Thromboelastography and thromboelastometry represent viscoelastic diagnostic methodologies with promising application to diseases of altered coagulation. Their use in trauma-induced coagulopathy as a means of assessing the real-time status of the patient's functional coagulation profile in addition to its impact on effective and appropriate use of blood product support has been gaining acceptance among trauma surgeons, anesthesiologists, and transfusion medicine specialists. However, the ability of viscoelastic testing to augment or supplant conventional coagulation testing for the diagnosis and management of trauma-induced coagulopathy remains controversial. Many of these issues pertain to the differences in methodology, instrumentation, logic, accessibility, ease of use, operator variability, and the method's relationship to patient care, blood product use, cost, and conventional testing algorithms.
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Survivors of critical illness often have significant long-term brain dysfunction, and routine clinical procedures like mechanical ventilation (MV) may affect long-term brain outcome. We aimed to investigate the effect of the increase of tidal volume (Vt) on brain activation in a rat model. ⋯ MV promoted brain activation. The intensity of the response was higher in HVt animals, suggesting an iatrogenic effect of MV on the brain. These findings suggest that this novel cross-talking mechanism between the lung and the brain should be explored in patients undergoing MV.
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Because patient-ventilator asynchrony (PVA) is recognized as a major clinical problem for patients undergoing ventilatory assistance, automatic methods of PVA detection have been proposed in recent years. A novel approach is airflow spectral analysis, which, when related to visual inspection of airway pressure and flow waveforms, has been shown to reach a sensitivity and specificity of greater than 80% in detecting an asynchrony index of greater than 10%. The availability of automatic non-invasive methods of PVA detection at the bedside would likely be of benefit in intensive care unit practice, but they may be limited by shortcomings, so clear proof of their effectiveness is needed.