21 Mar 08
Posted in Early goal directed therapy, ScvO2 at 21:40 by Laci
By E Rivers
Chest 2006;129:507-508
Mixed venous oxygen saturation (SvO2) in sepsis is commonly referred to as an end point of low impact on clinical decisions in sepsis patients because of the following common refrain: “SvO2 is always increased in septic ICU patients.” However, there are fundamental principles that render this modality clinically useful when applying it to the supply-dependent phase of sepsis (ie, global tissue hypoxia). The presence of global tissue hypoxia not only has pathologic significance in vitro, but there is a pathologic link among the clinical presence of global tissue hypoxia (ie, low SvO2 and cardiac index), the generation of inflammatory mediators, and mitochondrial impairment of oxygen utilization that is seen in septic ICU patients. Furthermore, identifying sudden episodes of supply dependency in septic ICU patients (ie, sudden decreases in SvO2) has diagnostic and prognostic significance. With this background, the rationale for using central venous oxygen (ScvO2) saturation as a surrogate for SvO2 to detect and treat global tissue hypoxia in the most proximal phase of sepsis management (supply dependency) was the basis for its use in the Early Goal Directed Therapy in Severe Sepsis and Septic Shock Study (EGDT).
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Posted in Early goal directed therapy, Fluid management, Inotropic support, Sepsis at 21:37 by Laci
By M W Donnino, B Nguyen, G Jacobsen, M Tomlanovich and E Rivers
Chest 2003;124:90S
Despite the current definition of septic shock, patients with normal or high blood pressure may still display global tissue hypoxia. The following study evaluates early, goal-directed therapy (EGDT) in patients with severe sepsis in the absence of hypotension.
METHODS
This is a post-hoc anlysis of patients presenting to an urban ED in severe sepsis and septic shock. Patients were included if they had SIRS critieria, lactic acidosis (> 4 mmol/liter), and mean arterial pressure (MAP) > 100 mm Hg. Patients were randomized to conventional care (inclusive of central venous pressure (CVP) monitoring) or EGDT. EGDT consisted of 6 hours of resuscitation to goals of CVP between 8–12, MAP between 65–90, and central venous oximetry (ScvO2) greater than 70%.
RESULTS
There was no difference in mean MAP (116.0 mm Hg in the control and 117.6 mm Hg in the treatment group), and there was no difference in APACHE, MODS, and SAPS scores between groups. Forty-eight patients (23 in the control group and 25 in the EGDT group) were analyzed. The mortality was 60.9% in the control group compared to 20% in the EGDT group [p < 0.004]. The mean initial ScvO2 was 45 % and 44 % in the control and treatment groups respectively. At six hours, ScvO2 was higher in the EGDT (76% versus 59%), whereas the lactate and MODS score were reduced (p < 0.05). The EGDT group received more total intravenous fluids than the treatment group (p < 0.05) during the first six hours. At sixty days, mortality in the control (70%) and in the treament group (24%) remained significant (p=0.002).
CONCLUSIONS
This study confirms that patients with severe sepsis accompanied by lactic acidosis may display global tissue hypoxia in the absence of hypotension. Early identification and goal-directed therapy of this subgroup leads to a reduction in morbidity and mortality.
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Posted in Coronary artery disease, Echocardiography at 21:34 by Laci
By PS Douglas et al.
J Am Coll Cardiol 2008; 51:1127-1147
The American College of Cardiology Foundation (ACCF) and the American Society of Echocardiography (ASE) together with key specialty and subspecialty societies, conducted an appropriateness review for stress echocardiography. The review assessed the risks and benefits of stress echocardiography for several indications or clinical scenarios and scored them on a scale of 1 to 9 (based upon methodology developed by the ACCF to assess imaging appropriateness). The upper range (7 to 9) implies that the test is generally acceptable and is a reasonable approach, and the lower range (1 to 3) implies that the test is generally not acceptable and is not a reasonable approach. The midrange (4 to 6) indicates a clinical scenario for which the indication for a stress echocardiogram is uncertain.
The indications for this review were drawn from common applications or anticipated uses, as well as from current clinical practice guidelines. Use of stress echocardiography for risk assessment in patients with coronary artery disease (CAD) was viewed favorably, while routine repeat testing and general screening in certain clinical scenarios were viewed less favorably. It is anticipated that these results will have a significant impact on physician decision making and performance, reimbursement policy, and will help guide future research.
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17 Mar 08
Posted in Anesthesia, Valvular disease at 19:53 by Laci
By R Ramaraj, V L Sorrell
BMJ 2008;336:550-555
Aortic stenosis is the most common valvular lesion in Europe and North America. It primarily presents as calcific aortic stenosis in 2-7% of the population aged >65 years. About 80% of adult patients with symptomatic aortic stenosis are male. As 1-2% of the population is born with a congenital bicuspid aortic valve and populations are ageing, aortic stenosis is becoming more common. By 2020, about 3.5 million people in England are expected to have aortic sclerosis and 150000 will have severe aortic stenosis. Here we provide an overview to help diagnosis and a summary of the management of AS and its sequelae. Many of the points made in this review are based on randomised controlled trials. However, observational studies and the guideline recommendations of the American Heart Association and the American College of Cardiology and of the European Society of Cardiology are also included to provide comprehensive overviews that are beyond the scope of this article.
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