25 Aug 06
Posted in Anticoagulation, Critical Care at 9:06 by Laci
By M Crowther and W Lim
Critical Care 2006, 10:150
Antithrombotic prophylaxis in critically ill patients frequently fails. Venous thromboembolism is associated with adverse clinical outcomes, including a prolonged intensive care unit stay and death. A potential mechanism by which critically ill patients may be predisposed to antithrombotic failure is the inability to achieve ‘prophylactic’ anticoagulant drug levels as a result of impaired absorption. For example, previous studies have shown that patients on inotropes have reduced serum levels of low molecular weight heparin, presumably on the basis of reduced absorption from the subcutaneous injection site. In the previous issue of the journal, Rommers and colleagues examined whether subcutaneous edema reduces absorption of a low molecular weight heparin; although small, and thus underpowered, the authors failed to find any relationship between the level of low molecular weight heparin and the presence of edema. These findings provide reassurance that subcutaneously administered medications may be used in critically ill patients with edema.
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Posted in Critical Care at 9:05 by Laci
By MD Levine and E Boyer
Critical Care 2006, 10:149
Hyperinsulinemia-euglycemia (HIE) therapy, when initiated promptly and aggressively, may offer considerable advantages in the treatment of calcium channel blocker poisoning. Although its mechanism of action is uncertain, HIE improves the efficiency with which the poisoned myocardium uses metabolic fuel, the end result of which is improvements in inotropy and other cardiovascular parameters. Although HIE is not universally accepted, the reports included in the previous issue of Critical Care should prompt clinicians to consider HIE an appropriate therapy specifically for calcium channel blocker poisoning
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Posted in ALI/ARDS, Non-invasive ventilation at 9:03 by Laci
By E Garpestad and NS Hill
Critical Care 2006, 10:147
The selection of patients with acute lung injury/acute respiratory distress syndrome (ALI/ARDS) to receive noninvasive ventilation (NIV) is challenging, partly because there are few reliable selection criteria. The study by Rana and colleagues in the previous issue of Critical Care identifies metabolic acidosis and a lower oxygenation index as predictors of NIV failure, although it is unable to identify threshold values. It also demonstrates that treating patients with NIV for ALI/ARDS and shock is an exercise in futility. Future studies need to focus on criteria that will enable selection of patients for whom NIV will have a high likelihood of success
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Posted in Anesthesia, Critical Care, Sepsis at 9:02 by Laci
By Z Mohammad, B Afessa and JD Finkielman
Critical Care 2006, 10:R105
Etomidate blocks adrenocortical synthesis when it is administered intravenously as a continuous infusion or a single bolus. The influence of etomidate administration on the incidence of relative adrenal insufficiency in patients with septic shock has not been formally investigated. The objective of this study was to determine the incidence of relative adrenal insufficiency in patients with septic shock after etomidate administration compared with patients with septic shock who did not receive etomidate.
Methods
In this retrospective study, 152 adults with septic shock who had a consyntropin stimulation test between March 2002 and August 2003 in a tertiary medical center were included. Relative adrenal insufficiency was defined as a rise in serum cortisol = 9 µg/dl after the administration of 250 µg of consyntropin. Patients were divided into those who did and those who did not receive etomidate before the stimulation test. The proportion of patients with relative adrenal insufficiency in these two groups was compared using Fischer’s exact test. A P of value < 0.05 was considered statistically significant.
Results
The mean age of the patients was 64 years, 59% of patients were male, 97% of patients were white and their hospital mortality rate was 57%. Thirty-eight patients (25%) received etomidate before the cosyntropin stimulation test, and the median (interquartile range) time interval between the administration of the drug and the test was 7 (4–10) hours. The incidence of relative adrenal insufficiency was 76% in the patients who received etomidate compared with 51% in the patients who did not (P = 0.0077).
Conclusion
The incidence of relative adrenal insufficiency in patients with septic shock is increased when the stimulation test is performed after the administration of etomidate.
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