Critical care : the official journal of the Critical Care Forum
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Comparative Study
Discordance between microvascular permeability and leukocyte dynamics in septic inducible nitric oxide synthase deficient mice.
Microvascular dysfunction causing intravascular leakage of fluid and protein contributes to hypotension and shock in sepsis. We tested the hypothesis that abrogation of inducible nitric oxide synthase (iNOS) activation would decrease leukocyte rolling, leukocyte adhesion, and microvascular leakage in sepsis. We compared wild-type mice made septic by cecal ligation and puncture with mice deficient in iNOS. ⋯ Leukocyte adhesion and vascular leakage were discordant in this setting. The finding that septic iNOS-deficient mice exhibited less microvascular leakage than wild-type septic mice despite equivalent increases in leukocyte adhesion suggests an important role for nitric oxide in modulating vascular permeability during sepsis.
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In the previous issue of Critical Care Chenaud and colleagues found that most intensive care unit patients who had given informed consent for their participation in a clinical trial could not recall either the purpose of the trial or its related risks several days later. These findings should remind us that informed consent is a process, not an event, but they should not be interpreted to mean that recall is, of itself, a useful criterion for evaluating either the validity or the quality of the informed consent process. On an entirely separate note, the decision of the authors not to obtain informed consent for this study itself raises interesting questions about the ethics of doing research on the ethics of doing research.
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Editorial Comment
Selenium supplementation in critically ill patients: can too much of a good thing be a bad thing?
A recent study by Forceville and colleagues evaluated the effect of high-dose selenium administration as a treatment for septic shock. The study was negative and conflicts with existing clinical data regarding selenium administration in critically ill patients. Perhaps the key to understanding the differences between these discrepant observations lies in considering the dose and timing of selenium administration.
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Editorial Comment
Corticosteroids to prevent postextubation upper airway obstruction: the evidence mounts.
Intubation of the airway can lead to laryngotracheal injury, resulting in extubation failure from upper airway obstruction (UAO). A number of factors can help to identify patients who are at greatest risk for postextubation UAO. Three randomized controlled trials demonstrate that prophylactic corticosteroids decrease the risk for postextubation UAO and probably the need for re-intubation.
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Clinical data considering vasopressin as an equivalent option to epinephrine in cardiopulmonary resuscitation (CPR) are limited. The aim of this prehospital study was to assess whether the use of vasopressin during CPR contributes to higher end-tidal carbon dioxide and mean arterial blood pressure (MAP) levels and thus improves the survival rate and neurological outcome. ⋯ End-tidal carbon dioxide and MAP are strong prognostic factors for the outcome of out-of-hospital cardiac arrest. Resuscitated patients treated with vasopressin alone or followed by epinephrine have higher average and final end-tidal carbon dioxide values as well as a higher MAP on admission to the hospital than patients treated with epinephrine only. This combination vasopressor therapy improves restoration of spontaneous circulation, short-term survival, and neurological outcome. In the subgroup of patients with initial asystole, it improves the hospital discharge rate.