Base administration or fluid bolus for preventing morbidity and mortality in preterm infants with metabolic acidosis.

BACKGROUND: Metabolic acidosis in the early newborn period is associated with adverse outcomes in preterm infants. The most commonly used strategies to correct metabolic acidosis are intravascular infusion of base, for example sodium bicarbonate, and intravascular infusion of a fluid bolus, usually a crystalloid or colloid solution. OBJECTIVES: To evaluate the available evidence from randomised controlled trials that either infusion of base, or of a fluid bolus, reduces mortality and adverse neurodevelopmental outcomes in preterm infants with metabolic acidosis. SEARCH STRATEGY: We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2005), MEDLINE (1966 - January 2005), EMBASE (1980 - January 2005), CINAHL (1982 - January 2005). SELECTION CRITERIA: Randomised or quasi-randomised controlled trials that evaluated the following treatments for preterm infants with metabolic acidosis:1. Infusion of base versus no treatment.2. Infusion of fluid bolus versus no treatment.3. Infusion of base versus fluid bolus. DATA COLLECTION AND ANALYSIS: We extracted the data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two authors, and synthesis of data using relative risk and risk difference. MAIN RESULTS: We found two small randomised controlled trails that fulfilled the eligibility criteria (Corbet 1977; Dixon 1999). Corbet 1977 compared treating infants with sodium bicarbonate infusion (N = 30) versus no treatment (N = 32) and did not find evidence of an effect on mortality [Relative risk 1.39 (95% confidence interval 0.72 to 2.67), risk difference 0.12 (95% confidence interval -0.12 to 0.36)], or in the incidence of intra/peri-ventricular haemorrhage [Relative risk 1.24 (95% confidence interval 0.47 to 3.28), risk difference 0.05 (95% confidence interval -0.16 to 0.25)]. Dixon 1999 compared treatment with sodium bicarbonate (N = 16) versus fluid bolus (N = 20). The primary outcome assessed was arterial blood pH/base excess two hours after the intervention. Other clinical outcomes were not reported. Neither trial assessed longer term neurodevelopmental outcomes. AUTHORS' CONCLUSIONS: There is insufficient evidence from randomised controlled trials to determine whether infusion of base or fluid bolus reduces morbidity and mortality in preterm infants with metabolic acidosis. Further large randomised trials are needed.

The neorule: a new instrument to measure linear growth in preterm infants.

OBJECTIVES: To compare measurements of crown-heel length (CHL) made with the neorule with CHL measurements made with a stadiometer in term infants. To examine safety and reproducibility of CHL measurements in infants < 32 weeks gestational age (GA) using the neorule. METHODS: Three measurements of CHL were made by three teams during the first 2 days of life in healthy term infants. One team used the stadiometer and two the neorule. Two different teams made three measurements of CHL on four occasions at two week intervals in infants less than 32 weeks GA. Infants were continuously monitored, and any adverse event was recorded. RESULTS: Fifty term infants were studied, median (range) birth weight 3440 (2020-5010) g. The mean (SD, 95% confidence interval) difference between values obtained with the stadiometer and neorule was 0.08 (6.22, -1.69 to +1.85) mm and between the two neorule teams was 0.8 (4.48, -0.47 to +2.08) mm. Twenty preterm infants were studied, GA median (range) 29 (25(+0)-31(+6)) weeks, median (range) CHL 397 (339-475) mm. There were no adverse events. The difference (SD, 95%CI) between teams in the mean CHL measurement was 0.18 (4.79, -1.02 to +1.38) mm, with interobserver limit of agreement -9.2 to +9.6 mm and coefficient of variation 1.2%. There were no significant differences between measurements made by single observers; the F ratio was 0.449 (df = 61, p = 0.6). CONCLUSION: The neorule is a safe and accurate way to measure CHL in newborn infants.