A hydrophilic interaction liquid chromatography - Tandem mass spectrometry method for the determination of phenylephrine in dried blood spots from preterm infants.

A sensitive and accurate hydrophilic interaction liquid chromatography - tandem mass spectrometry method (HILIC-MS/MS) was developed and validated for the determination of phenylephrine concentration in Dried Blood Spot (DBS) samples from preterm infants, after ocular administration of an ophthalmic solution with phenylephrine. Sample preparation involved the extraction of the analyte from an 85 µL DBS sample with methanol - acetonitrile (50:50, v/v). Chromatographic separation was achieved on an ACQUITY UPLC BEH AMIDE column, under isocratic conditions within a 5 min run. Detection was achieved with a triple quadrupole MS applying electrospray ionization in positive mode. The method was fully validated and proved precise and accurate with in a linear range of 0.59-3.53 ng/ml in blood. The method was developed to provide insights on the level of exposure of infant population to phenylephrine after ocular administration.

Customized compared to population-based centiles for detecting term small for gestational age infants in Greece.

BACKGROUND: Applying customized centiles may improve the accuracy of detecting small for gestational age (SGA) infants; however, the evidence is inconclusive whether adjusted centiles are more sensitive in identifying infants at increased risk of morbidity. We aimed to examine the validity of customized centiles in a Greek cohort and evaluate their performance compared to population-based centiles in predicting infants at risk of increased morbidity. METHODS: We prospectively recorded the neonatal and maternal characteristics of singleton, low-risk, term infants over a year. Infants were defined as SGA if their birth weight was under the tenth centile, classified both by population-based centiles and customized centiles, adjusted for maternal and innate factors. We performed a comparative analysis utilizing linear regression analysis and calculating the receiver operating characteristics (ROC) curves. RESULTS: Overall 657 infants were identified. Population-based centiles detected 42 (6 %) SGA infants, while customized centiles 80 (12 %). Perinatal morbidity was associated with an odds ratio of 1.02 with customized centiles [95 % confidence interval (CI): 1.01-1.04] and with an odds ratio of 1.02 with population-based centiles (95 % CI: 1.02-1.02). In predicting perinatal morbidity, no significant difference was detected between customized centiles [area under the ROC curve 0.773 (95 % CI: 0.699-0.847)] and population-based centiles [area under the ROC curve 0.737 (95 % CI: 0.662-0.813)] (p =0.272). CONCLUSIONS: Customized centiles provided increased accuracy in comparison to the population-based centiles in detecting SGA term infants. However, customized centiles had no better impact on predicting a poor perinatal outcome. HIPPOKRATIA 2020, 24(3): 133-137.