Inpatient comparison of wireless and wired pulse oximetry in neonates.

BACKGROUND: To compare oxygen saturation (SpO2) and heart rate (HR) recorded by a reference wired pulse oximeter to a wireless pulse oximeter in inpatient neonates. METHODS: Term infants born≥37 + 0 weeks and preterm infants born≤35 + 0 weeks gestation were enrolled and time-matched data pairs were obtained. The primary outcome was intraclass correlation coefficient and r-values between the two oximeters for heart rate and oxygen saturation. RESULTS: Thirty term and 20 preterm neonates were enrolled. There was a high degree of correlation between the two oximeters for HR (r = 0.926) among all 50 infants, and excellent interclass correlation (ICC = 0.961), but there were no bradycardia episodes in either term or preterm infants. There was a lesser degree of correlation for SpO2 values in the term and preterm groups (r = 0.242; 0.521, respectively) along with moderate interclass correlation (ICC = 0.719) but few episodes of hypoxemia≤90% occurred in enrolled subjects. CONCLUSIONS: There were no significant differences between the wireless and reference wired oximeters for assessing HR. There was less correlation between the two oximeters for monitoring SpO2 in both the term and preterm group. Wireless pulse oximetry may have practical advantages for use in inpatient neonates, but additional studies are needed that include bradycardia and desaturation events to delineate this question.

Large-scale analysis of ion channel gene expression in the mouse heart during perinatal development.

The immature and mature heart differ from each other in terms of excitability, action potential properties, contractility, and relaxation. This includes upregulation of repolarizing K(+) currents, an enhanced inward rectifier K(+) (Kir) current, and changes in Ca(2+), Na(+), and Cl(-) currents. At the molecular level, the developmental regulation of ion channels is scantily described. Using a large-scale real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assay, we performed a comprehensive analysis of ion channel transcript expression during perinatal development in the embryonic (embryonic day 17.5), neonatal (postnatal days 1-2), and adult Swiss-Webster mouse hearts. These data are compared with publicly available microarray data sets (Cardiogenomics project). Developmental mRNA expression for several transcripts was consistent with the published literature. For example, transcripts such as Kir2.1, Kir3.1, Nav1.5, Cav1.2, etc. were upregulated after birth, whereas others [e.g., Ca(2+)-activated K(+) (KCa)2.3 and minK] were downregulated. Cl(-) channel transcripts were expressed at higher levels in immature heart, particularly those that are activated by intracellular Ca(2+). Defining alterations in the ion channel transcriptome during perinatal development will lead to a much improved understanding of the electrophysiological alterations occurring in the heart after birth. Our study may have important repercussions in understanding the mechanisms and consequences of electrophysiological alterations in infants and may pave the way for better understanding of clinically relevant events such as congenital abnormalities, cardiomyopathies, heart failure, arrhythmias, cardiac drug therapy, and the sudden infant death syndrome.