Skin blood flow changes during apneic spells in preterm infants

Changes in skin blood flow during apneic spells were determined in 18 preterm infants using a diode laser Doppler flow meter without light conducting fibres. Heart rate, nasal air flow, impedance pneumography, skin and incubator temperature and laser Doppler skin blood flow were recorded simultaneously in each infant. During 212 apneic spells with a duration of 11.6 ± 7.5 s (mean ± S.D.) (range 6.0–48.0 s), the laser Doppler skin blood flow was measured. In all children except one, the majority of the apneic spells was associated with a decrease in skin blood flow. During 155 apneic spells (73%) skin blood flow decreased significantly P < 0.025), the maximum decrease being 16.7 ± 14.8%, 28.5 ± 23.9% and 18.9 ± 16.1% (mean ± S.D.) for central, obstructive and mixed apneic spells, respectively. The decrease in skin blood flow started immediately after the beginning of apneic spells in 71%, the rest started with a mean delay of 3.4 s (range 0.1–7.0 s). No relation was found between the decrease in skin blood flow and the duration of the apneic spells. Thirty-four percent of the apneic spells were accompanied by bradycardia. In apneic spells accompanied by bradycardia the decrease in skin blood flow was not related to the fall in heart rate

A compact differential laser Doppler velocimeter using a semiconductor laser

A small differential laser Doppler velocimeter which uses a semiconductor laser and a small number of optical components is described. In this device the light from the laser diode is split into coherent beams by means of a diffraction grating. The two first-order beams are crossed in a probe volume with a lens. In a test experiment the velocity of water containing 0.9 mu m polystyrene spheres was determined from the fluctuation of the scattered light. This velocity agreed with the velocity calculated from flux measurements

Signal processing for a laser-Doppler blood perfusion meter

Two signal processing methods for laser-Dopper perfusion velocimetry are presented. The methods are based on the calculation of the moments of the frequency power spectrum. The first uses Vω-filtering (ω is the frequency) with analogous electronics, the second uses signal autocorrelation with digital electronics. Comparison is made with a third instrument: a spectrum analyzer coupled to a computer, using Fourier transform tecniques. The performance of these setups (sensitivity, limit sensitivity and accuracy) are investigated. We propose a calibration standard for signal processors to be used for blood perfusion measurements. The analogous instrument proved to be the cheapest but the digital instrument had the best performance

The Career Costs of Children

This paper analyzes the life-cycle career costs associated with child rearing and decomposes their effects into unearned wages (as women drop out of the labor market), loss of human capital, and selection into more child-friendly occupations. We estimate a dynamic life-cycle model of fertility, occupational choice, and labor supply using detailed survey and administrative data for Germany for numerous birth cohorts across different regions. We use this model to analyze both the male-female wage gap as it evolves from labor market entry onward and the effect of pro-fertility policies. We show that a substantial portion of the gender wage gap is explainable by realized and expected fertility and that the long-run effect of policies encouraging fertility are considerably lower than the short-run effects typically estimated in the literature

Liever inleiden dan afwachten bij aterme zwangerschapshypertensie en milde preeclampsie: HYPITAT-studie

OBJECTIVE: To investigate what would benefit women with mild full-term pregnancy-related hypertension most: induction of labour or expectant monitoring, from the perspective of clinical effectiveness, maternal quality of life, and costs. DESIGN: Randomised clinical trial. Trial registration number ISRCTN08132825. METHODS: We undertook a multicentre randomised controlled trial in 38 hospitals in the Netherlands between October 2005 and March 2008. We enrolled patients with a singleton pregnancy in cephalic presentation at 36-41 weeks' gestation, who had gestational hypertension or mild preeclampsia. Participants were randomly allocated to receive either induction of labour or expectant monitoring. The primary outcome was a composite measure of poor maternal outcome, defined as maternal mortality, maternal morbidity (eclampsia, 'haemolysis, elevated liver enzymes, low platelets' (HELLP) syndrome, pulmonary oedema, thrombo-embolic disease and abruptio placentae), progression to severe hypertension or proteinuria, and major postpartum haemorrhage. Secondary outcomes were mode of delivery, neonatal outcome, maternal quality of life and costs. Analysis was by intention to treat. RESULTS: A total of 756 patients were allocated to receive induction of labour (n = 377 patients) or expectant monitoring (n = 379). No cases of maternal or neonatal death or eclampsia were recorded. Development of poor maternal outcome was significantly lower in the induction of labour group (117 women) than the expectant monitoring group (166 women) (31% versus 44%; relative risk 0.71 (95% CI: 0.59-0.86); p < 0.001). The caesarean section rate was lower among women in the induction of labour group (n = 54) compared to women in the expectant monitoring group (n = 72) (14% versus 19%; relative risk 0.75 (95% CI: 0.55-1.04)< p = 0.085). Neonatal outcomes and quality of life were comparable between both groups. Induction of labour is a cost saving strategy (difference euro 831). CONCLUSION: For women with full-term gestational hypertension and pre-eclampsia, induction of labour is associated with improved maternal outcome and lower costs, without the additional risk of a caesarean section being necessary