Oxygen Saturation Profiles in Healthy Term Infants in Early Postnatal Life.

OBJECTIVE: Oxygen saturation profiles generated by pulse oximetry are used as a clinical tool in the neonatal intensive care unit (NICU). There is limited evidence on normal oxygen saturation profile values in term infants. This study aimed to determine oxygen saturation profiles over an 8-hour monitoring period among healthy term neonates between 24 and 48 hours after birth. STUDY DESIGN: A prospective cohort study of healthy term neonates born at 37 to 41 weeks of gestation. Preductal oxygen saturations were continuously monitored for an 8-hour period between 24 and 48 hours of life using pulse oximetry. Oxygen profile histograms were recorded for analysis. The average percent oxygen saturation (SpO2) was measured over the entire study duration for each neonate and was characterized as the fraction of time of their SpO2 reading was in each of five intervals: ≤80, 81 to 84, 85 to 89, 90 to 94, and 95 to 100%. RESULTS: Seventy-five neonates were included in the study. Median SpO2 was 95.4%. Percentage time spent in each of the five SpO2 intervals was as follows: 0.07 (≤80), 0.15 (81-84), 0.88 (85-89), 26.9 (90-94), and 67.3% (95-100%). Eighteen infants (24%) spent the highest percentage of time in SpO2 of 90 to 94%. CONCLUSION: This study provides reference ranges for oxygen profiles in healthy term neonates during 24 to 48 hours of life. Nearly one-quarter of newborns spent the highest percentage of time in SpO2 of 90 to 94%. This data is important when interpreting oxygen saturation profiles of term neonates admitted to the NICU. KEY POINTS: · This study provide reference ranges for oxygen profiles in healthy term neonates during 24 to 48 hours.. · Median SpO2 was 95.4%.. · Nearly one quarter of newborns spent the highest percentage of time in SpO2 of 90 to 94%..

Newly Identified Nematodes from Mono Lake Exhibit Extreme Arsenic Resistance.

Extremophiles have much to reveal about the biology of resilience, yet their study is limited by sampling and culturing difficulties [1-3]. The broad success and small size of nematodes make them advantageous for tackling these problems [4-6]. We investigated the arsenic-rich, alkaline, and hypersaline Mono Lake (CA, US) [7-9] for extremophile nematodes. Though Mono Lake has previously been described to contain only two animal species (brine shrimp and alkali flies) in its water and sediments [10], we report the discovery of eight nematode species from the lake, including microbe grazers, parasites, and predators. Thus, nematodes are the dominant animals of Mono Lake in species richness. Phylogenetic analysis suggests that the nematodes originated from multiple colonization events, which is striking, given the young history of extreme conditions at Mono Lake [7, 11]. One species, Auanema sp., is new, culturable, and survives 500 times the human lethal dose of arsenic. Comparisons to two non-extremophile sister species [12] reveal that arsenic resistance is a common feature of the genus and a preadaptive trait that likely allowed Auanema to inhabit Mono Lake. This preadaptation may be partly explained by a variant in the gene dbt-1 shared with some Caenorhabditis elegans natural populations and known to confer arsenic resistance [13]. Our findings expand Mono Lake's ecosystem from two known animal species to ten, and they provide a new system for studying arsenic resistance. The dominance of nematodes in Mono Lake and other extreme environments and our findings of preadaptation to arsenic raise the intriguing possibility that nematodes are widely pre-adapted to be extremophiles.

Pulse oximetry screening for critical congenital heart disease in planned out-of-hospital births.

OBJECTIVES: To describe the use of pulse oximetry screening (POS) for critical congenital heart disease (CCHD). STUDY DESIGN: This observational study of Wisconsin out-of-hospital births was performed from January to November, 2013. Licensed midwives, Amish birth attendants, and public health nurses were trained in the use of pulse oximetry to detect CCHD, supplied with pulse oximeters, and reported screening results and clinical outcomes. RESULTS: Results of POS in 440 newborns were reviewed; 173/440 births were from Amish or Mennonite communities. Prenatal ultrasonography was performed in less than one-half of the pregnancies and in only 13% of Amish and Mennonite women. A total of 432 babies passed the screening, 5 babies were incorrectly assigned to have passed or failed, and 3 babies failed the screening. Two of the babies who failed the screening were treated for sepsis and the third had congenital heart disease. There was 1 false negative result (coarctation of the aorta and ventricular septal defect). CONCLUSIONS: This study provides information on the use of POS for CCHD in out-of-hospital births and shows that POS can be successfully implemented outside the hospital setting. Although the failure rate in this small sample was higher than reported in studies of hospital births, those babies failing the screening had significant disease processes that were identified more rapidly because of the screening.

Pulse oximetry screening in Wisconsin.

INTRODUCTION: Pulse oximetry can be used as a screening tool to detect critical congenital heart disease (CCHD) in neonates prior to hospital discharge and the development of symptoms. Newborns suspected of having CCHD based on pulse oximetry screening should have the diagnosis excluded or confirmed with echocardiography. However, echocardiography is not immediately available in all settings in which newborns are delivered and the best course of action in these settings remains to be determined. The purpose of this study was to evaluate the resources available to diagnose and treat newborns with CCHD born in the state of Wisconsin. METHODS: We surveyed the nurse managers or administrators of the 99 Wisconsin hospitals in which babies are routinely delivered in the state of Wisconsin. A telephone survey was performed in February and March 2011. The number of births per facility was estimated from the most recent available data (2010). RESULTS: There were 66 179 total births occurring in 106 hospitals in the state of Wisconsin in 2010, with 99 hospitals routinely delivering newborns. Surveys were completed in 88/99 (88.9%), representing 95% of the state's in-hospital births. All responding hospitals had pulse oximetry available in the nursery. Twenty-five of 88 (28.4%) of responding hospitals routinely use pulse oximetry to screen for CCHD, representing 35.2% of surveyed hospital births. Same-day neonatal echocardiography was available at 33/88 (37.5%) of the responding hospitals, representing 74.4% of surveyed hospital births. The average distance to the higher-level care facility of choice from the hospitals without neonatal echocardiography is 53.1 miles. CONCLUSION: Pulse oximetry is universally available in Wisconsin newborn nurseries, and pulse oximetry screening for CCHD is currently being performed for many of Wisconsin's newborns. The majority of births in Wisconsin occur in hospitals where same-day neonatal echocardiography is available for confirmatory diagnosis of CCHD when necessary.

Neonatal spinal cord injury after an uncomplicated vaginal delivery.

Neonatal spinal cord injury has been reported after traumatic births and as a consequence of underlying lesions in the spinal cord. This report describes an infant who was born with bilateral flaccid paralysis of the upper extremities after an atraumatic, noninstrumented vaginal delivery. The infant was otherwise neurologically intact. The infant was initially thought to exhibit bilateral brachial plexus injury. However, magnetic resonance imaging demonstrated an upper cervical spinal cord hemorrhage, with no underlying lesions of the spinal cord or surrounding vasculature. This case highlights the importance of thoroughly evaluating any neurologic deficit in the newborn, and suggests that normal mechanical forces of labor and delivery may be sufficient to cause damage to the newborn spinal cord.

Cord blood zinc protoporphyrin/heme ratio in minority neonates at risk for iron deficiency.

We measured cord blood zinc protoporphyrin/heme (ZnPP/H) and plasma ferritin in healthy African-American and Hispanic newborns, matched by gestation with Caucasian newborns. In these at-risk minorities, cord ZnPP/H was higher and plasma ferritin lower, supporting the feasibility of screening newborns at-risk for iron deficiency at birth.