Economic evaluation of S. boulardii CNCM I-745 for prevention of antibioticassociated diarrhoea in hospitalized patients.

Interest in administration of probiotics to prevent antibiotic-associated diarrhoea (AAD) in hospitalized patients is increasing. We determined the cost of antibiotic-associated diarrhoea in hospital settings for non-complicated and Clostridium difficile (C.diff) complicated AAD, and performed a health-economic analysis of AAD prevention with S. boulardii CNCM I-745 (S. boulardii) from data collected in 1 university and 3 regional hospitals in Flanders. Using a decision tree analytic model, costs and effects of S. boulardii for AAD prevention are calculated. Incremental costs due to AAD, including increased length of hospitalization, were calculated using bottom-up and top-down costing approaches from a hospital, healthcare payer (HCP) and societal perspective. Model robustness was tested using sensitivity analyses. Additional costs per hospitalized patient range from € 277.4 (hospital) to € 2,150.3 (societal) for non-complicated and from € 588.8 (hospital) to € 2,239.1 (societal) for C. diff. complicated AAD. Using S. boulardii as AAD prevention results in cost savings between € 50.3 (bottom-up) and € 28.1 (topdown) per patient treated with antibiotics from the HCP perspective; and € 95.2 and € 14.7 per patient from the societal and hospital perspectives. Our analysis shows the potential for using S. boulardii as AAD prophylactic treatment in hospitalized patients. Based on 831,655 hospitalizations with antibiotic administration in 2014 and € 50.3 cost saving per patient on antibiotics, generalized use of S. boulardii could result in total annual savings up to € 41.8 million for the Belgian HCP.

Determining carotid artery pressure from scaled diameter waveforms: comparison and validation of calibration techniques in 2026 subjects.

Calibrated diameter distension waveforms could provide an alternative for local arterial pressure assessment more widely applicable than applanation tonometry. We compared linearly and exponentially calibrated carotid diameter waveforms to tonometry readings. Local carotid pressures measured by tonometry and diameter waveforms measured by ultrasound were obtained in 2026 subjects participating in the Asklepios study protocol. Diameter waveforms were calibrated using a linear and an exponential calibration scheme and compared to measured tonometry waveforms by examining the mean root-mean-squared error (RMSE), carotid systolic blood pressure (SBPcar) and augmentation index (AIx) of calibrated and measured pressures. Mean RMSE was 5.2(3.3) mmHg (mean(stdev)) for linear and 4.6(3.6) mmHg for exponential calibration. Linear calibration yielded an underestimation of SBPcar by 6.4(4.1) mmHg which was strongly correlated to values of brachial pulse pressure (PPbra) (R = 0.4, P < 0.05). Exponential calibration underestimated true SBPcar by 1.9(3.9) mmHg, independent of PPbra. AIx was overestimated by linear calibration by 1.9(10.1)%, the difference significantly increasing with increasing AIx (R = 0.25, P < 0.001) and by exponential calibration by 5.4(10.6)%, independently of the value of AIx. Properly calibrated diameter waveforms offer a viable alternative for local pressure estimation at the carotid artery. Compared to linear calibration, exponential calibration significantly improves the pressure estimation.

Nonlinear isochrones in murine left ventricular pressure-volume loops: how well does the time-varying elastance concept hold?

The linear time-varying elastance theory is frequently used to describe the change in ventricular stiffness during the cardiac cycle. The concept assumes that all isochrones (i.e., curves that connect pressure-volume data occurring at the same time) are linear and have a common volume intercept. Of specific interest is the steepest isochrone, the end-systolic pressure-volume relationship (ESPVR), of which the slope serves as an index for cardiac contractile function. Pressure-volume measurements, achieved with a combined pressure-conductance catheter in the left ventricle of 13 open-chest anesthetized mice, showed a marked curvilinearity of the isochrones. We therefore analyzed the shape of the isochrones by using six regression algorithms (two linear, two quadratic, and two logarithmic, each with a fixed or time-varying intercept) and discussed the consequences for the elastance concept. Our main observations were 1) the volume intercept varies considerably with time; 2) isochrones are equally well described by using quadratic or logarithmic regression; 3) linear regression with a fixed intercept shows poor correlation (R(2) < 0.75) during isovolumic relaxation and early filling; and 4) logarithmic regression is superior in estimating the fixed volume intercept of the ESPVR. In conclusion, the linear time-varying elastance fails to provide a sufficiently robust model to account for changes in pressure and volume during the cardiac cycle in the mouse ventricle. A new framework accounting for the nonlinear shape of the isochrones needs to be developed.