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To determine whether intermittent hypoxia (IH) persisting after 36 weeks postmenstrual age (PMA) can be attenuated using caffeine doses sufficient to maintain caffeine concentrations >20 μg ml−1. Twenty-seven infants born 20 μg ml−1 on study caffeine doses. IH was significantly attenuated through 38 weeks PMA compared with the control group. Caffeine doses of 14 to 20 mg kg−1 day−1 were sufficient to maintain caffeine concentrations >20 μg ml−1 and reduce IH in preterm infants at 36 to 38 weeks PMA.

BackgroundPreterm infants are frequently exposed to intermittent hypoxia (IH) associated with apnea and periodic breathing that may result in inflammation and brain injury that later manifests as cognitive and executive function deficits. We used a rodent model to determine whether early postnatal exposure to IH would result in inflammation and brain injury.MethodsRat pups were exposed to IH from P2 to P12. Control animals were exposed to room air. Cytokines were analyzed in plasma and brain tissue at P13 and P18. At P20-P22, diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS) were performed.ResultsPups exposed to IH had increased plasma Gro/CXCL1 and cerebellar IFN-γ and IL-1β at P13, and brainstem enolase at P18. DTI showed a decrease in FA and AD in the corpus callosum (CC) and cingulate gyrus, and an increase in RD in the CC. MRS revealed decreases in NAA/Cho, Cr, Tau/Cr, and Gly/Cr; increases in TCho and GPC in the brainstem; and decreases in NAA/Cho in the hippocampus.ConclusionsWe conclude that early postnatal exposure to IH, similar in magnitude to that experienced in human preterm infants, is associated with evidence for proinflammatory changes, decreases in white matter integrity, and metabolic changes consistent with hypoxia.

Aims Caffeine concentrations in preterm infants are usually measured in the blood. However, salivary assays may provide a valid and practical alternative. The present study explored the validity and clinical utility of salivary caffeine concentrations as an alternative to blood concentrations and developed a novel plasma/salivary caffeine distribution model. Methods Paired salivary and plasma samples were obtained in 29 infants. Salivary samples were obtained using a commercially available salivary collection system. Caffeine concentrations in the saliva and plasma were determined using high-performance liquid chromatography. A population pharmacokinetic (PK) model was developed using NONMEM 7.3. Results The mean (± standard deviation) gestational age (GA) at birth and birth weight were 27.9 ± 2.1 weeks and 1171.6 ± 384.9 g, respectively. Paired samples were obtained at a mean postmenstrual age (PMA) of 35.5 ± 1.1 weeks. The range of plasma caffeine concentrations was 9.5–54.1 μg ml−1, with a mean difference (95% confidence interval) between plasma and salivary concentrations of −0.18 μg ml−1 (−1.90, 1.54). Salivary and plasma caffeine concentrations were strongly correlated (Pearson's correlation coefficient = 0.87, P

Reported here are the proceedings of a symposium given in honor of Dr. Henry F. Krous upon his retirement as Clinical Professor of Pathology and Pediatrics at the University of California Schools of Medicine, and as Director of the San Diego SIDS/SUDC Research Project. Dr. Krous' distinguished 37-year-career was dedicated to research into sudden unexpected death in infancy and childhood, notably the sudden infant death syndrome (SIDS) and sudden unexplained death in childhood (SUDC). The presentations were given at the International Conference on Stillbirth, SIDS, and infant survival on October 5, 2012, in Baltimore, MD, USA. Eight colleagues of Dr. Krous whose own professional careers were touched by his efforts discussed forensic issues related to SIDS, tissue banking, animal models in SIDS, brainstem studies in SIDS, genetic studies in SIDS, establishment of a SUDC registry, neuropathologic research in SUDC, and potential shared mechanisms underlying sudden and unexpected death in early life. The wide scope of the presentations crossed the disciplines of forensic pathology, pediatric pathology, neuropathology, neuroscience, physiology, genetics, and bereavement, and attest to Dr. Krous' far-reaching influence upon SIDS and SUDC research.

Preterm infants have immature respiratory control and resulting intermittent hypoxia (IH). The extent of IH after stopping routine caffeine treatment and the potential for reducing IH with extended caffeine treatment are unknown.To determine (1) the frequency of IH in premature infants after discontinuation of routine caffeine treatment and (2) whether extending caffeine treatment to 40 weeks' postmenstrual age (PMA) reduces IH.A prospective randomized clinical study was conducted at 16 neonatal intensive care units in the United States, with an 18-month enrollment period. Preterm infants (32 weeks' gestation) previously treated with caffeine were randomized to extended caffeine treatment or usual care (controls) at a PMA of at least 34 weeks but less than 37 weeks. Continuous pulse oximeter recordings were obtained through 40 weeks' PMA. Oximeter data were analyzed by persons masked to patient group.Continued treatment with caffeine.Number of IH events and seconds with less than 90% hemoglobin oxygen saturation (Sao2) per hour of recording.Our analysis included 95 preterm infants. In control infants, the mean (SD) time at less than 90% Sao2 at 35 and 36 weeks' PMA was 106.3 (89.0) and 100.1 (114.6) s/h, respectively. The number of IH events decreased significantly from 35 to 39 weeks' PMA (P = .01). Extended caffeine treatment reduced the mean time at less than 90% Sao2 by 47% (95% CI, -65% to -20%) to 50.9 (48.1) s/h at 35 weeks and by 45% (95% CI, -74% to -17%) to 49.5 (52.1) s/h at 36 weeks.Substantial IH persists after discontinuation of routine caffeine treatment and progressively decreases with increasing PMA. Extended caffeine treatment decreases IH in premature infants.clinicaltrials.gov Identifier: NCT01875159.

We have reached a conundrum in assigning cause of death for sudden unexpected infant deaths. We summarize the discordant perspectives and approaches and how they have occurred, and recommend a pathway toward improved consistency. This lack of consistency affects pediatricians and other health care professionals, scientific investigators, medical examiners and coroners, law enforcement agencies, families, and support or advocacy groups. We recommend that an interdisciplinary international committee be organized to review current approaches for assigning cause of death, and to identify a consensus strategy for improving consistency. This effort will need to encompass intrinsic risk factors or infant vulnerability in addition to known environmental risk factors including unsafe sleep settings, and must be sufficiently flexible to accommodate a progressively expanding knowledge base.