Prospective study of a non-restrictive decision rule for acute aortic syndrome.

OBJECTIVES: To determine the impact of a non-restrictive clinical decision rule on CT utilization for Emergency Department patients suspected of having an acute aortic syndrome (AAS). METHODS: We prospectively assessed the performance of a previously described, collaboratively designed, non-restrictive clinical decision rule for AAS. Emergency Department patients with suspected AAS were stratified into low and high-risk groups based on decision rule results, from July 2013-August 2014. Patients with acute trauma, prior AAS or aortic surgery were excluded. CT dose reduction protocols were concurrently implemented as a quality improvement measure. Bivariate analysis was performed to compare the prospective cohort with the historical derivation cohort for CT utilization rates, results of CT, AAS incidence and radiation exposure. The performance of the clinical decision rule was evaluated. RESULTS: Compared with the historic cohort, the study cohort demonstrated a lower CT utilization rate [0.344% (427/124,093) versus 0.477% (1465/306,961), (p<0.001)], a trend toward higher CT diagnostic yield [4.4% (19/427) versus 2.7% (40/1465), (p=0.08)]. AAS incidence was similar [0.015% (19/124,093) versus 0.013% (40/306,961), (p=0.57)]. The mean effective radiation dose was markedly lower [12±5.5mSv versus 43±20mSv, (p<0.0001)]. The clinical decision rule correctly stratified only 56% (10/18) of patients with AAS as high-risk. CONCLUSIONS: A non-restrictive, collaboratively designed, clinical decision rule for Emergency Department patients with suspected AAS performed poorly in risk-stratifying patients for AAS. However, its implementation was associated with a significant and safe decrease in CT utilization.

The "injection jet sign": an innovative method of needle position confirmation during ultrasound guided injections.

Ultrasound (US)-guided therapeutic and diagnostic injections play an important role in day-to-day clinical practice for many radiologists. When compared with fluoroscopic or computed tomographic (CT) methods of localization, US offers the benefit of real-time confirmation of instrument position without exposing the patient to any ionizing radiation. Target delivery is usually confirmed by direct needle tip visualization and with real-time demonstration of capsular or bursal distention. While often more technically difficult in deeper anatomic spaces, larger patients and smaller delivery needles, US should still be considered the preferred method of image guidance because of these outlined benefits. We present here three cases demonstrating an innovative method of needle-tip position confirmation, termed the "injection jet sign." This technique represents a useful supplement to routine sonographic guidance and allows the clinician to enjoy the benefits of this imaging modality even in the face of other technical challenges.

Nitric oxide and superoxide in rat mesangial cells: modulation by C-reactive protein.

BACKGROUND: C-reactive protein (CRP) has been linked to cardiovascular and renal disease. We evaluated the effects of CRP on the production of nitric oxide (NO) and superoxide by rat mesangial cells (RMC) and the impact on cell function. METHODS AND RESULTS: RMC were incubated with cytokines (IFN-gamma, IL-1beta, and LPS) and CRP (10-100 microg/ml) for 24-72 h. Exposure to CRP resulted in a time- and dose-dependent reduction in NO accumulation (p<0.05). Although inducible nitric oxide synthase (iNOS) protein expression was unaltered after 48 h, CRP stimulated expression of HSP90. Steady state abundance of iNOS mRNA increased nearly threefold after a 24-h exposure to CRP. Incubation with 100 microg/ml CRP for 60-120 min resulted in a 272% increase in superoxide production that was prevented by diphenyleneiodium chloride but not L-NAME (p<0.0001). CONCLUSION: CRP enhances superoxide release in RMC, which in turn inactivates NO and reduces net production. The functional relevance of these CRP-induced changes is supported by increased expression of HSP90 in RMC exposed to the mediator. These findings suggest that systemic inflammation, which contributes to the pathogenesis of atherosclerosis, may play a role in the progression of kidney disease.