Bilirubin measurement for neonates: comparison of 9 frequently used methods.

OBJECTIVE: High blood concentrations of bilirubin are toxic to the brain and may cause kernicterus. Therefore, determination of bilirubin levels is performed for many newborns, and several different methods are available. We compared 9 frequently used methods for bilirubin determination among newborns under routine conditions, to define their sequence of use. METHODS: In a prospective study, bilirubin concentrations were determined with 9 different methods, ie, 3 skin test devices, 3 nonchemical photometric devices (including 2 blood gas analyzers), and 3 laboratory analyzers. RESULTS: A total of 124 samples were obtained. All 3 laboratory methods showed very strong correlations with each other, and their means were used as comparison values. To these comparison values, the skin test devices had correlation coefficients between 0.961 and 0.966, and the nonchemical photometric devices between 0.980 and 0.994. Bland-Altman plots demonstrated good agreement with the comparison values for all nonchemical photometric devices. All skin test devices and 1 nonchemical photometric device underestimated bilirubin levels, particularly at high concentrations. CONCLUSIONS: In the routine care of newborns, the first method for bilirubin testing should be a skin test. If the skin test result exceeds 200 micromol/L and other analytes are to be determined with a nonchemical photometric device, then bilirubin can be included in this analysis and the result trusted up to 250 micromol/L. If the skin test result exceeds 200 micromol/L and only bilirubin concentrations are needed, then a standard laboratory method is the first choice, to avoid repeated blood sampling. Bilirubin concentrations from nonchemical photometric devices that exceed 250 micromol/L should be confirmed with standard laboratory methods.

Effect of topical 1.25% povidone-iodine eyedrops used for prophylaxis of ophthalmia neonatorum on renal iodine excretion and thyroid-stimulating hormone level.

The 1% silver nitrate, which has been used for preventing gonococcal conjunctivitis in the neonate, is not effective against Chlamydia trachomatis and may provoke eye irritation. It is not known whether the alternative topical agent, 1.25% povidone-iodine, can influence thyroid function. In this study, no influence of povidone-iodine on thyroid function was observed.

Evaluation of the Glucometer Elite XL device for screening for neonatal hypoglycaemia.

UNLABELLED: To prevent persistent neurodevelopment and physical growth deficits in neonatal care, it is mandatory to determine blood glucose levels as quickly and precisely as possible, preferably using micro-methods. However, most commercially available instruments have not been validated and approved for this purpose. The aim of this study was to validate the Glucometer Elite XL, a newly developed device for point-of-care testing (POCT). In samples from 869 newborn infants, glucose levels were simultaneously measured by the Glucometer Elite XL in whole blood and by an accepted clinical laboratory method in haemolysed blood using the ECA 2000 device. An acceptable method agreement was found between the POCT and the ECA 2000 method (mean difference 0.013 mmol/l, SD 0.69). As determined by regression analysis (Passing-Bablok), the slope was 1.086 with a y-intercept of -0.4 mmol/l ( r =0.959, P <0.05). The differences between measurement pairs of both assays versus the haematocrit were negligible. With a cut-off for hypoglycaemia at 2.6 mmol/l glucose in haemolysed blood, the sensitivity of the POCT device was 0.63 and specificity was 0.98. Raising the cut-off of the Glucometer Elite XL to 3.2 mmol/l, the sensitivity and specificity incremented to 1.0 and 0.89, respectively. CONCLUSION: The Glucometer Elite XL instrument can be recommended for point-of-care blood glucose measurement in newborn infants if its character as a screening method is taken into account. To compensate deviating results, we advise to shift its cut-off for hypoglycaemia recognition to a safe threshold of 3.2 mmol/l. However, hypoglycaemia has to be confirmed by a valid glucose measurement in the clinical laboratory.

Benefit and risk of heparin for maintaining peripheral venous catheters in neonates: a placebo-controlled trial.

OBJECTIVES: Heparin addition to infusion fluids is used to prolong catheter patency in newborns. Heparin may also induce adverse effects such as bleeding complications and immune-mediated heparin-induced thrombocytopenia (HIT). One objective was peripheral venous catheter patency with heparinization of continuous infusions (0.5 IU/mL). Secondary objectives were incidences of bleeding, clinically manifest HIT, HIT antibodies, and catheter-related complications. STUDY DESIGN: Inclusion criteria were anticipated need for intravenous peripheral infusion (>or=5 days for HIT-related endpoints) and postnatal age <28 days at study entry. Exclusion criteria were bodyweight <1000 g, congenital malformation, need for therapeutic anticoagulation or mechanical ventilation, and severe bleeding. HIT antibodies were assessed by enzyme-linked immunosorbent assay. RESULTS: A total of 145 infants received heparin, and 151 infants received saline. Patient characteristics, number of additional drugs, duration of treatment, and location and size of catheters did not differ. Patency of catheters was 7.4 hours longer in the heparin group (33.8 hours vs 26.4 hours, P<.0001), but the total numbers of catheters did not differ (565 vs 692, P=.3). No infant developed HIT antibodies. Incidences of bleeding complications and thrombocytopenia were comparable between groups. CONCLUSIONS: Balancing the benefits against the risks of heparin addition and the rare complication of HIT, we will not use 0.5 IU/mL heparin addition to parenteral fluids.