Manipulations of the murine genome that alter cardiovascular function have created the need for methods to study cardiovascular physiology in genetically altered animals in vivo. We adapted chronic physiological measurement techniques to the nonanesthetized, nonrestrained murine model, established strain-specific cardiovascular and metabolic norms, and evaluated responses to anesthesia, exercise, and adrenergic stimulation. Anesthesia resulted in alterations in heart rate (HR), blood pressure (BP), and O2 consumption (V(O2)) and CO2 production (V(CO2)) for up to 6 h postoperatively. There were significant interstrain differences in resting values of HR and BP Graded treadmill exercise resulted in linear increases in HR, V(O2), V(CO2), and respiratory exchange ratio (RER) similar to those seen in larger species. Response to beta-adrenergic stimulation showed a classic sigmoidal dose-response curve; however, there was very little tachycardiac response to vagal blockade, indicating low resting vagal tone. This study demonstrates the feasibility of performing chronic cardiovascular measurements in nonanesthetized mice and stresses the importance of allowing for anesthetic recovery and strain variability. Murine cardiovascular responses to exercise can be reliably measured and are qualitatively similar to those in humans.

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Background Necrotizing enterocolitis (NEC) is a major complication confronting clinicians caring for premature infants. This investigation compares clinical outcomes before and after quality improvement–program interventions in a population of premature infants at intermediate risk for NEC. Methods This study is a retrospective single‐center chart review of infants admitted with a birth weight of 1000–1499 g, excluding major congenital anomalies, over a 6‐year period, beginning with implementation of a donor breast‐milk program when mother's own milk was not available. Infants were separated into 2 epochs, before (July 2012–December 2013) and after (April 2014–June 2018) introduction of human milk–derived fortifier (Prolacta) and a daily probiotic (FloraBABY) supplement. Results Comparing 140 preintervention infants with 265 postintervention infants, NEC was significantly lower in the postintervention group: 5.2% vs 1.1% (P = 0.046). Somatic growth was similar in both epochs. Conclusions Quality‐improvement initiatives utilizing an exclusive human‐milk diet and daily probiotic supplementation were associated with a decreased incidence of NEC in infants with a birth weight of 1000–1499 g. Implementation of the NEC reduction bundle did not affect infant growth.

Management of newborn infants fell in-hospital is especially challenging given the limited signs and symptoms of intracranial hemorrhage in this age group. We present a case of a four day old well appearing newborn infant found to have a severe epidural hemorrhage requiring emergent surgical drainage. Development of imaging protocols for newborn infants suffering in-hospital falls need to consider the potential consequences of missing actionable intracranial hemorrhage when relying on clinical observation as a management strategy.

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