Mitral valve Doppler for cardiac output assessment in preterm neonates.

INTRODUCTION: Cardiac output (CO) assessment in neonates is commonly done by echocardiography. It is unclear which is the best site to measure the left ventricular (LV) outflow tract for CO assessment (the aortic valve [AV] aortic sinus [AS] or the sinotubular junction [STJ]). In the normal heart, the blood flow entering the LV equals the blood ejected from it. Therefore, measuring the blood flow into the LV through the mitral valve (MV) is an alternative way to measure CO. METHODS: In stable preterm infants the MV CO was compared with the right ventricular (RV) CO and the three ways to measure LV CO, in 30 stable preterm neonates. Interobserver variability for MV CO was established. RESULTS: In the 30 neonates studied, MV CO was best correlated and had a minimal bias to the RV CO and LV CO measured at the STJ. Left ventricular CO measured at the AV and AS had significant bias relative to RV CO and MV CO. MV CO inter-observer variability was similar to other echocardiographic CO assessment methods. CONCLUSION: MV CO may be used as an alternative way to assess CO. The STJ may be the optimal site to measure LV outflow tract.

The Saga of Pulse Oximetry Screening for Critical Congenital Heart Disease in Israel: A Historical Perspective.

BACKGROUND: Many countries have adopted a mandatory routine pulse oximetry screening of newborn infants to identify babies with otherwise asymptomatic critical congenital heart disease (CCHD). OBJECTIVES: To describe the current status of pulse oximetry CCHD screening in Israel, with a special emphasis on the experience of the Shaare Zedek Medical Center. METHODS: We review the difficulties of the Israeli Medical system with adopting the SaO2 screening, and the preliminary results of the screening at the Shaare Zedek Medical Center, both in terms of protocol compliance and CCHD detection. RESULTS: Large scale protocol cannot be implemented in one day, and regular quality assessment programs must take place in order to improve protocol compliance and identify the reasons for protocol failures. CONCLUSIONS: Quality control reviews should be conducted soon after implementation of the screening to allow for prompt diagnosis and quick resolution.

Safety assessment of probiotics for human use.

The safety of probiotics is tied to their intended use, which includes consideration of potential vulnerability of the consumer or patient, dose and duration of consumption, and both the manner and frequency of administration. Unique to probiotics is that they are alive when administered, and unlike other food or drug ingredients, possess the potential for infectivity or in situ toxin production. Since numerous types of microbes are used as probiotics, safety is also intricately tied to the nature of the specific microbe being used. The presence of transferable antibiotic resistance genes, which comprises a theoretical risk of transfer to a less innocuous member of the gut microbial community, must also be considered. Genetic stability of the probiotic over time, deleterious metabolic activities, and the potential for pathogenicity or toxicogenicity must be assessed depending on the characteristics of the genus and species of the microbe being used. Immunological effects must be considered, especially in certain vulnerable populations, including infants with undeveloped immune function. A few reports about negative probiotic effects have surfaced, the significance of which would be better understood with more complete understanding of the mechanisms of probiotic interaction with the host and colonizing microbes. Use of readily available and low cost genomic sequencing technologies to assure the absence of genes of concern is advisable for candidate probiotic strains. The field of probiotic safety is characterized by the scarcity of studies specifically designed to assess safety contrasted with the long history of safe use of many of these microbes in foods.

Visual screening versus transcutaneous bilirubinometry for predischarge jaundice assessment.

OBJECTIVE: Comparison of visual screening with transcutaneous bilirubinometry (TcB) in identifying neonates with plasma total bilirubin (PTB) > or =75th percentile. DESIGN: In 100 paired readings PTB was 34 +/- 24 micromol/L higher than the TcB counterpart. A TcB reading of 154 micromol/L was therefore regarded as equivalent to a PTB of 188 micromol/L, corresponding to the 75th percentile at 48 h. Predischarge, all newborns were evaluated for jaundice, first by visual inspection and then transcutaneously. PTB was ordered as indicated by visual assessment or if the TcB reading was > or =154 micromol/L. RESULTS: Of 346 newborns tested, 25 (7.2%) had a PTB concentration > or =75th percentile. Forty-nine had PTB determinations based on TcB compared with 83 by visual assessment. However, a similar number of affected newborns was identified by each method (21/25 (84%) by visual screening vs. 18/25 (72%) by TcB). PTB concentrations of those who had been chosen by TcB were higher than those selected visually (202 +/- 24 micromol/L vs. 186 +/- 31 micromol/L). CONCLUSIONS: A practical method for predischarge detection of neonates with plasma total bilirubin concentration > or = 75th percentile, implementing transcutaneous bilirubinometry, is described. The transcutaneous technique required fewer blood tests than visual assessment for similar yield.