Use of polymerase chain reaction as a diagnostic tool for neonatal sepsis can result in a decrease in use of antibiotics and total neonatal intensive care unit length of stay.

OBJECTIVE: To retrospectively determine if a negative 16S ribosomal RNA (rRNA) polymerase chain reaction (PCR) (PCR(-)) could lead to a decrease in the number of antibiotic doses and neonatal intensive care unit (NICU) length of stay (LOS) for infants admitted to the NICU for presumed early-onset sepsis (EOS) with negative blood culture results (BC(-)). STUDY DESIGN: Analysis included 419 infants, greater than 35 weeks gestational age, with PCR(-), BC(-) and LOS > 48 h. Both the investigators and clinical care team were unaware of the PCR results. The actual number of antibiotic doses (AAD) administered was compared to an estimated number of antibiotics doses (EAD) that would have been given until PCR(-) results were available by 18 h. The number of antibiotic doses saved was calculated as (AAD-EAD). The actual NICU LOS in hours (aLOS) for a subset of infants who remained in the hospital primarily for antibiotic therapy was compared to an estimated LOS (eLOS) if infants with PCR(-) were discharged from the NICU when clinically stable. The number of hours saved was calculated as (aLOS-eLOS). RESULTS: Approximately eight antibiotic doses and 85 NICU hours per infant could be saved using PCR(-) results available at 18 h. CONCLUSIONS: Use of 16S rRNA PCR could decrease the number of antibiotics doses and NICU LOS for infants admitted for EOS. This may facilitate: (1) earlier NICU discharge; (2) parental satisfaction; and (3) decreased health care costs.

Quantitative Doppler assessment of valvular regurgitation.

BACKGROUND: Quantitation of valvular regurgitation remains a challenge. The accuracy of quantitative Doppler is controversial, and its ability to measure regurgitant volume is unknown; therefore, it is not widely used. METHODS AND RESULTS: In 120 patients (20 without regurgitation, 19 with aortic regurgitation, and 81 with mitral regurgitation), the stroke volume through the mitral annulus and left ventricular outflow tract were measured using pulsed-wave Doppler concurrently with left ventricular stroke volume calculated using left ventricular volumes measured by two-dimensional echocardiography Simpson's biapical method. Regurgitant volume and fraction were thus computed using Doppler or ventricular methods. In normal patients there were good correlations between Doppler and left ventricular measurements of stroke volume. Doppler regurgitant volume and fraction were 4.4 +/- 4.4 mL and 5.3 +/- 4.5%, respectively. In patients with aortic regurgitation, there were good correlations between Doppler and left ventricular measurements of stroke volume, regurgitant volume, and regurgitant fraction (r = 0.97, r = 0.95, and r = 0.93, respectively; p < 0.0001). In patients with mitral regurgitation, despite good correlations between Doppler and ventricular methods for stroke volume, regurgitant volume, and regurgitant fraction (r = 0.94, r = 0.93, and r = 0.94, respectively; p < 0.001), these variables were overestimated by Doppler. However, in the last 54 patients compared with the first 27, overestimation decreased significantly for regurgitant volume (5 +/- 10 mL versus 18 +/- 27 mL, p < 0.05) and regurgitant fraction (3.3 +/- 6.7% versus 6.2 +/- 6.8%, p = 0.05). CONCLUSIONS: Quantitative Doppler can be performed in large numbers of patients in a clinical laboratory. Its potential limitation was identified as overestimation of mitral regurgitation, which is overcome with increased experience. Its achieved accuracy in mitral and aortic regurgitation allows measurement not only of regurgitant fraction but most importantly of regurgitant volume.