The E/e' Ratio: As "Critical" As the Left Ventricular Ejection Fraction?

Ascertainment of the left ventricular ejection fraction is the primary reason for ordering echocardiography in the acute care setting; however, this parameter does not provide information regarding a patient's volume status. As such, it cannot be reliably used to inform decisions regarding intravenous fluid resuscitation or diuresis, particularly in undifferentiated dyspnea and hypotension. This is relevant given a national quality improvement exhortation to provide aggressive fluid resuscitation as part of a "sepsis bundle." This initiative must be tempered by the well-established increase in hospital mortality from providing intravenous fluid to patients with unrecognized heart failure, which may occur if sepsis is misdiagnosed. We describe herein, what is to our knowledge, the first description of a critically elevated Doppler ratio of mitral inflow peak E-wave velocity to the mean mitral annular velocity as a harbinger of sudden death from pulmonary edema in a patient treated with aggressive intravenous fluids as part of the "sepsis bundle." This is utilized as a springboard for proposing a clinical algorithm focused on expedited echocardiography. It emphasized the potential value of advancing markedly the diastolic assessment of filling pressure (ratio of mitral inflow peak E-wave velocity to the mean mitral annular velocity) in the acute care setting to a level of import comparable to the left ventricular ejection fraction.

A DXA Whole Body Composition Cross-Calibration Experience: Evaluation With Humans, Spine, and Whole Body Phantoms.

New densitometer installation requires cross-calibration for accurate longitudinal assessment. When replacing a unit with the same model, the International Society for Clinical Densitometry recommends cross-calibrating by scanning phantoms 10 times on each instrument and states that spine bone mineral density (BMD) should be within 1%, whereas total body lean, fat, and %fat mass should be within 2% of the prior instrument. However, there is limited validation that these recommendations provide adequate total body cross-calibration. Here, we report a total body cross-calibration experience with phantoms and humans. Cross-calibration between an existing and new Lunar iDXA was performed using 3 encapsulated spine phantoms (GE [GE Lunar, Madison, WI], BioClinica [BioClinica Inc, Princeton, NJ], and Hologic [Hologic Inc, Bedford, MA]), 1 total body composition phantom (BioClinica), and 30 human volunteers. Thirty scans of each phantom and a total body scan of human volunteers were obtained on each instrument. All spine phantom BMD means were similar (within 1%; <-0.010 g/cm2 bias) between the existing and new dual-energy X-ray absorptiometry unit. The BioClinica body composition phantom (BBCP) BMD and bone mineral content (BMC) values were within 2% with biases of 0.005 g/cm2 and -3.4 g. However, lean and fat mass and %fat differed by 4.6%-7.7% with biases of +463 g, -496 g, and -2.8%, respectively. In vivo comparison supported BBCP data; BMD and BMC were within ∼2%, but lean and fat mass and %fat differed from 1.6% to 4.9% with biases of +833 g, -860 g, and -1.1%. As all body composition comparisons exceeded the recommended 2%, the new densitometer was recalibrated. After recalibration, in vivo bias was lower (<0.05%) for lean and fat; -23 and -5 g, respectively. Similarly, BBCP lean and fat agreement improved. In conclusion, the BBCP behaves similarly, but not identical, to human in vivo measurements for densitometer cross-calibration. Spine phantoms, despite good BMD and BMC agreement, did not detect substantial lean and fat differences observed using BBCP and in vivo assessments. Consequently, spine phantoms are inadequate for dual-energy X-ray absorptiometry whole body composition cross-calibration.