Aim:Blood sampling from umbilical artery catheters decreases cerebral blood volume and cerebral oxygenation.The aim of this study was to assess the impact of sampling volume and velocity.Methods:Forty-eight infants,me...Aim:Blood sampling from umbilical artery catheters decreases cerebral blood volume and cerebral oxygenation.The aim of this study was to assess the impact of sampling volume and velocity.Methods:Forty-eight infants,median birthweight 965 g(480-1500 g),median gestational age 27 wk(23-34 wk),were studied during routine blood sampling from umbilical artery catheters.The sampling procedure was performed following a strict protocol for draw-up volume(1.6 ml),sampling volume(1.7 ml or 0.2 ml),re-injection volume(1.6 ml)and flushing volume(0.6 ml),time of aspiration(40 s or 80 s),reinjection(30 s)and flushing(6 s).In each infant,sampling volume and aspiration time were subject to sequential variation in a randomized fashion(1.7 ml/40 s,1.7 ml/80 s,0.2 ml/30 s).Using near-infrared spectroscopy,changes in concentrations of cerebral oxygenated and deoxygenated haemoglobin were measured,and changes in cerebral blood volume and cerebral oxygenation were calculated.Results:During all three sampling procedures,oxygenated haemoglobin decreased significantly from baseline,whereas deoxygenated haemoglobin did not change.Correspondingly,a decrease in cerebral blood volume and cerebral oxygenation occurred.This decrease was not affected significantly by extending the sampling time from 40 s to 80 s,whereas it was blunted by reducing the amount of blood withdrawn.Conclusion:Blood sampling from umbilical artery catheters induces a decrease in cerebral blood volume and cerebral oxygenation.The magnitude of the decrease depends on the blood volume withdrawn but not on sampling velocity.展开更多
Aims:1.To determine the survival and morbidity of infants at discharge with a birthweight of less than 1500 g in the geographically defined population of Ea st Anglia.2.To demonstrate a cost-effective method of region...Aims:1.To determine the survival and morbidity of infants at discharge with a birthweight of less than 1500 g in the geographically defined population of Ea st Anglia.2.To demonstrate a cost-effective method of regional data collectio n.3.To determine whether there were any changes in the demand for neonatal car e.Study design and subjects:A prospective cohort analysis using a single datab ase to collect data on 1244 very low birthweight infants from eight neonatal uni ts in one Region from 1993 to 1997.Results:Estimated ascertainment of VLBW inf ants to the study was 96%.Over the 5 years survival rates were stable(75-79 %).52%of deaths in infants admitted for neonatal care occurred on day 1,with just 15%of deaths occurring after 28 days of life.Mortality risk significantl y decreased with increasing gestational age at birth.Compared to 22-25-week o ld infants,the mortality risk decreased by 65%for 26-27-week old infants(OR 0.35 95%CI(0.21,0.59))and by 92%for 32-39-week old infants(OR 0.08 95% CI(0.03,0.21))with intermediate odds ratios of 0.22(0.12,0.42)and 0.13(0.06,0.28)for the 28-29 and 30-39 weeks gestation,respectively.Higher birthw eight,after adjusting for gestation also decreased the mortality risk(OR 0.78 per 100 g difference,95%CI(0.71,0.86)).No change was seen in the number of extremely preterm infants admitted for intensive care or resource utilisation,a lthough a significant increase was seen in the number of infants dying in delive ry rooms.There was a reduction in the reported incidence of pulmonary interstit ial emphysema(10-4%)but no change in the number of ventilation days or the r ate of chronic lung disease.The mean maternal age increased from 27.7 years to 28.9 years during the study.Maternal steroid administration increased(30%to 5 9%)and was associated with a decreased risk of mortality(OR 0.44,95%CI:0.3 1-0.62).Conclusions:It is possible to collect useful data from the neonatal p eriod at a reasonable cost from a geographically defined population.This inform ationwas used for informing clinicians,counselling parents and in the era of ma naged clinical networks will be useful in guiding the provision of effective hea lth care resources.展开更多
文摘Aim:Blood sampling from umbilical artery catheters decreases cerebral blood volume and cerebral oxygenation.The aim of this study was to assess the impact of sampling volume and velocity.Methods:Forty-eight infants,median birthweight 965 g(480-1500 g),median gestational age 27 wk(23-34 wk),were studied during routine blood sampling from umbilical artery catheters.The sampling procedure was performed following a strict protocol for draw-up volume(1.6 ml),sampling volume(1.7 ml or 0.2 ml),re-injection volume(1.6 ml)and flushing volume(0.6 ml),time of aspiration(40 s or 80 s),reinjection(30 s)and flushing(6 s).In each infant,sampling volume and aspiration time were subject to sequential variation in a randomized fashion(1.7 ml/40 s,1.7 ml/80 s,0.2 ml/30 s).Using near-infrared spectroscopy,changes in concentrations of cerebral oxygenated and deoxygenated haemoglobin were measured,and changes in cerebral blood volume and cerebral oxygenation were calculated.Results:During all three sampling procedures,oxygenated haemoglobin decreased significantly from baseline,whereas deoxygenated haemoglobin did not change.Correspondingly,a decrease in cerebral blood volume and cerebral oxygenation occurred.This decrease was not affected significantly by extending the sampling time from 40 s to 80 s,whereas it was blunted by reducing the amount of blood withdrawn.Conclusion:Blood sampling from umbilical artery catheters induces a decrease in cerebral blood volume and cerebral oxygenation.The magnitude of the decrease depends on the blood volume withdrawn but not on sampling velocity.
文摘Aims:1.To determine the survival and morbidity of infants at discharge with a birthweight of less than 1500 g in the geographically defined population of Ea st Anglia.2.To demonstrate a cost-effective method of regional data collectio n.3.To determine whether there were any changes in the demand for neonatal car e.Study design and subjects:A prospective cohort analysis using a single datab ase to collect data on 1244 very low birthweight infants from eight neonatal uni ts in one Region from 1993 to 1997.Results:Estimated ascertainment of VLBW inf ants to the study was 96%.Over the 5 years survival rates were stable(75-79 %).52%of deaths in infants admitted for neonatal care occurred on day 1,with just 15%of deaths occurring after 28 days of life.Mortality risk significantl y decreased with increasing gestational age at birth.Compared to 22-25-week o ld infants,the mortality risk decreased by 65%for 26-27-week old infants(OR 0.35 95%CI(0.21,0.59))and by 92%for 32-39-week old infants(OR 0.08 95% CI(0.03,0.21))with intermediate odds ratios of 0.22(0.12,0.42)and 0.13(0.06,0.28)for the 28-29 and 30-39 weeks gestation,respectively.Higher birthw eight,after adjusting for gestation also decreased the mortality risk(OR 0.78 per 100 g difference,95%CI(0.71,0.86)).No change was seen in the number of extremely preterm infants admitted for intensive care or resource utilisation,a lthough a significant increase was seen in the number of infants dying in delive ry rooms.There was a reduction in the reported incidence of pulmonary interstit ial emphysema(10-4%)but no change in the number of ventilation days or the r ate of chronic lung disease.The mean maternal age increased from 27.7 years to 28.9 years during the study.Maternal steroid administration increased(30%to 5 9%)and was associated with a decreased risk of mortality(OR 0.44,95%CI:0.3 1-0.62).Conclusions:It is possible to collect useful data from the neonatal p eriod at a reasonable cost from a geographically defined population.This inform ationwas used for informing clinicians,counselling parents and in the era of ma naged clinical networks will be useful in guiding the provision of effective hea lth care resources.
