The Use of Low-Dose Dopamine in the Neonatal Intensive Care Unit.

Dopamine has been used for half a century in adult and pediatric patients for the treatment of hypotension, as well as for the theoretical prevention of acute kidney injury (AKI). Although activation of renal dopamine receptors leads to increased urine output, there is no evidence that low-dose dopamine reduces the incidence of AKI, need for dialysis, or death. Dopamine administration is also associated with multiple adverse effects, particularly in preterm infants. Despite the lack of evidence for its use, as well as the known adverse effects of dopamine, many neonatologists still use low-dose dopamine to prevent or treat AKI in neonates. In this review, we provide a summary of our current medical knowledge about the use of low-dose dopamine in the neonatal population.

The Use of Low-Dose Dopamine in the Neonatal Intensive Care Unit.

Dopamine has been used for half a century in adult and pediatric patients for the treatment of hypotension, as well as for the theoretical prevention of acute kidney injury (AKI). Although activation of renal dopamine receptors leads to increased urine output, there is no evidence that low-dose dopamine reduces the incidence of AKI, need for dialysis, or death. Dopamine administration is also associated with multiple adverse effects, particularly in preterm infants. Despite the lack of evidence for its use, as well as the known adverse effects of dopamine, many neonatologists still use low-dose dopamine to prevent or treat AKI in neonates. In this review, we provide a summary of our current medical knowledge about the use of low-dose dopamine in the neonatal population.

Characterization of the temporal, cell-specific and interferon-inducible patterns of indoleamine 2,3 dioxygenase 1 (IDO1) expression in the human placenta across gestation.

INTRODUCTION: The human placenta performs multiple functions necessary for successful pregnancy, but the metabolic pathways and molecular mechanisms responsible for regulating placental development and functions remain incompletely understood. Catabolism of the essential amino acid tryptophan has numerous critical roles in normal physiology, including inflammation. The kynurenine pathway, which accounts for ∼90% of tryptophan breakdown, is mediated by indoleamine 2,3 dioxygenase 1 (IDO1) in the placenta. In pregnant mice, alterations of IDO1 activity or expression result in fetal resorption and a preeclampsia-like phenotype. Decreased IDO1 expression at the maternal-fetal interface has also been linked to preeclampsia, in utero growth restriction and recurrent miscarriage in humans. These collective observations suggest essential role(s) for IDO1 in maintaining healthy pregnancy. Despite these important roles, the precise temporal, cell-specific and inflammatory cytokine-mediated patterns of IDO1 expression in the human placenta have not been thoroughly characterized across gestation. METHODS: Western blot and whole mount immunofluorescence (WMIF) were utilized to characterize and quantify basal and interferon (IFN)-inducible IDO1 expression in 1st trimester (7-13 weeks), 2nd trimester (14-22 weeks) and term (39-41 weeks) placental villi. RESULTS: IDO1 expression is activated in the human placenta between the 13th and 14th weeks of pregnancy, increases through the 2nd trimester and remains elevated at term. Constitutive IDO1 expression is restricted to placental endothelial cells. Interestingly, different types of IFNs have distinct effects on IDO1 expression in the human placenta. DISCUSSION: Our collective results are consistent with potential role(s) for IDO1 in the regulation of vascular functions in placental villi.

Plasma Citrulline as a Biomarker for Early Diagnosis of Necrotizing Enterocolitis in Preterm Infants.

OBJECTIVE: Citrulline synthesized by healthy enterocytes and decreases with injury. This work aimed to study plasma citrulline concentrations (CITs) as a biomarker to differentiate among infants presenting with early nonspecific signs and symptoms of necrotizing enterocolitis (NEC) with those who will develop NEC. Further to study the correlation between posttreatment CIT with time to full feeds (TTFF) and length of stay (LOS). STUDY DESIGN: This is a prospective study which included infants < 32 weeks gestational age (GA) with 9 infants each in Group 1 (stage 2/3 NEC), Group 2 (with stage 1 NEC-like presentation), and Group 3 (healthy GA-matched infants). CIT was measured in Groups 1 and 2 within 24 hours of presentation and again in Group 1 after treatment. RESULTS: The three groups were similar in clinical characteristics. Median CIT (µmol/L) in Group 1 (15.4 [interquartile range, IQR: 7.3-18.0]) was lower than Group 2 (22.2 [IQR: 18.3-27.3], p = 0.02) and Group 3 (24.9 [IQR: 19.8-31.9], p = 0.009). Posttreatment CIT in Group 1 did not correlate with TTFF (r = 0.15; p = 0.69) and LOS (r = - 0.33; p = 0.38). CONCLUSION: CIT was lower in infants with NEC as compared with healthy controls and those infants with nonspecific signs of NEC. CIT after treatment does not correlate with TTFF and LOS. KEY POINTS: · Citrulline is produced by enterocytes.. · It is decreased in infants with necrotizing enterocolitis early in disease.. · It can be used as a biomarker for early diagnosis of necrotizing enterocolitis..