RESUMO
Hypoxic-ischemic encephalopathy (HIE) is the leading cause of mortality among term newborns globally. Infants born through meconium-stained amniotic fluid are at risk of developing meconium aspiration syndrome (MAS) and HIE. Simultaneous occurrence of MAS and HIE is a perilous combination for newborns due to the risk of persistent pulmonary hypertension of the newborn (PPHN). Moreover, therapeutic hypothermia (TH), which is the current standard of care for the management of HIE, may increase pulmonary vascular resistance (PVR) and worsen PPHN. Infants with MAS and HIE require close cardiorespiratory and hemodynamic monitoring for PPHN. Therapeutic strategies, including oxygen supplementation, ventilation, use of surfactant, inhaled nitric oxide and other pulmonary vasodilators, and systemic vasopressors, play a critical role in the management of PPHN in MAS, HIE, and TH. While TH reduces death or disability in infants with HIE, infants with MAS and HIE undergoing TH need close hemodynamic monitoring for PPHN.
RESUMO
AIMS: This critical review aimed to summarize: (1) the variability and determinants of testosterone (T) measurements; and (2) reference values for the variability and determinants of T measurements in children. BACKGROUND: As T is a representative androgen, it has been widely used to explain male vulnerability to child health and developmental problems. T measurements in children, however, have been challenging because of low levels, diurnal and episodic secretion patterns, limited quantity and quality of the samples, and inconsistent study findings. METHODS: The search strategy used PubMed, CINAHL, Cochrane Library, Embase, Scopus, and Google Scholar. Studies published between 2008 through 2020 that examined factors influencing T measurement were included. The final 30 studies were selected using two appraisal forms. We extracted five categories of data from the reports. FINDINGS: Variability and determinants of T measurement included assay methods, the source of samples, and child demographic and environmental characteristics. T levels were higher 1-3 months after birth and in males up to 1 year; fewer sex differences were found up to 10-12 years. Serum T levels measured by using liquid chromatography-mass spectrometry were most reliable because immunoassays overestimated the levels, especially in neonates. T levels were stable at different temperatures and durations of storage, although sample collection remained an ongoing challenge for researchers. CONCLUSION: Depending on the study aims and feasibility, mass-spectrometry, multi-methods, and multi-materials are the recent trends in T measurement. Immunoassays may be an option if the study aims for relative rather than absolute comparisons.
