An evaluation of peak inspiratory pressure, tidal volume, and ventilatory frequency during ventilation with a neonatal self-inflating bag resuscitator.

BACKGROUND: Although the self-inflating bag is widely used in the hospital setting, variability of delivered ventilatory parameters is usually high, which might result in both hypoventilation and lung injury. The aims of this study were to assess possible sources of the high variability and to evaluate the adequacy of obtained values in relation to the recommended values for neonatal resuscitation. METHODS: This was an experimental study in which 172 health professionals (physicians, resident physicians, physiotherapists, nurses, and nursing technicians) who work with neonatal intensive care manually ventilated a test lung (adjusted to simulate the lungs of an intubated term newborn) with a self-inflating bag in 5 different handling techniques, using 10, 5, 4, 3, and 2 fingers. Delivered values of peak inspiratory pressure (PIP), tidal volume (V(T)), and ventilatory frequency (f) were compared, taking into account the different handling modalities and professions by analysis of variance for repeated measures. Chi-square, the Friedman test and the Fisher exact tests were performed to compare the delivered and standard values. RESULTS: PIP and V(T) were significantly affected by the handling technique, with higher values for a greater number of fingers used for ventilation. Profession also influenced V(T) and f significantly: physiotherapists tended to deliver higher volumes and lower rates. Nevertheless, we observed high variability of all studied ventilatory parameters and overall inadequacy of obtained values. Most volunteers delivered excessive pressures and volumes at insufficient ventilatory frequency. CONCLUSIONS: Delivered values seem to depend on operators' individual and professional differences, as well as on the number of fingers used to compress the bag. However, from the clinical point of view, it is important to point out the high occurrence of inadequate delivered values, regardless of handling technique and profession.

Temporal trends in intraventricular hemorrhage in preterm infants: A Brazilian multicenter cohort.

BACKGROUND: Intraventricular hemorrhage (IVH) is a serious problem in preterm infants. Brazilian national data are unknown. OBJECTIVE: To evaluate the incidence and temporal trend of IVH in very low birth weight (VLBW) preterm infants of 18 centers of the Brazilian Network on Neonatal Research. STUDY DESIGN: National prospective multicenter cohort study including inborn VLBW preterm infants aged 230/7- 336/7 weeks' gestation, admitted between 2013 and 2018. The center with the mean incidence rate was used as reference. We applied two adjustments models using perinatal variables, and perinatal + neonatal diseases. RESULTS: Of 6,420 infants, 1951/30.4% (range 27.1-33.8%) had IVH and the disease showed a significant trend towards an overall increase in incidence over time (p = 0.003), especially in three centers. Severe IVH (grade III or IV) occurred in 32.2% (range 29.2-34.5%) of those affected by IVH, with a stable incidence. After adjustments for perinatal variables, the differences persisted among centers: for global IVH, 7 centers had significantly lower rates (OR ranging from 0.31 to 0.62), and 2 presented rates higher than the reference center (OR ranging from 2.00 to 12.46) for severe HIV. Considering perinatal and neonatal variables, 6 centers had significantly lower rates (OR ranging from 0.36 to 0.60) for global IVH than the reference center and 3 had statistically higher rates (OR 1.72, 1.86 and 11.78) for severe forms. CONCLUSION: The incidence rate of IVH in this Brazilian cohort was high and it revealed an increasing trend towards over time. The severe IVH rate was also worrisome.

Trace mineral composition of human breast milk from Brazilian mothers.

BACKGROUND: Human milk is a dynamic food and some important differences in composition can be found between the milk from preterm and terms infants. Additionally, in some situations, the mother's own milk is unavailable and the use of milk from human milk banks is considered as the most appropriate substitute. In this way, concentrations of trace elements (Ba, Cu, Fe, Mn, Mo, Se, Sr, and Zn) were determined in human milk, considering the differences about preterm and term human milk and its processing in a human milk bank. METHODS: A total of 156 samples were analyzed, which were divided in three groups: samples collected at the hospital at bedside (BS, 60 samples) from mothers of preterm infants and samples from mothers of term infants collected in a human milk bank without pasteurization (WP, 49 samples) and pasteurized by the Holder procedure (P, 47 samples). The analyzes were conducted by inductively coupled plasma mass spectrometry (ICP-MS) after the treatment of the samples with acid mineralization assisted by microwave radiation. RESULTS: Concentrations varied in a range of 0.6-88.2 µg/L for Ba, 78.6-954.5 µg/L for Cu, 24.2-5229.2 µg/L for Fe, 0.4-42.6 µg/L for Mn, 0.1-39.1 µg/L for Mo, 2.5-70.6 µg/L for Se, 8.9-187.5 µg/L for Sr and 76.3-17727.2 µg/L for Zn. Significant differences (p < 0.05) were found between preterm (BS) and term human milk (WP and P) for Ba, Cu, Mo, Se, and Zn, whereas the processing of the donated milk by Holder pasteurization did not influence the concentration of the studied trace elements. The milk of term infants does not attend the recommended daily intake (RDI) of Zn and for preterm infants the RDI of Fe and Mn is not achieved. CONCLUSIONS: The higher concentrations of Cu, Mo, Se and Zn observed in milk from mothers of preterm infants indicate that the milk to be offered for these high-risk neonates in neonatal intensive care units should contain higher levels of these trace elements. Besides, considering the RDI, the milk of term infants should be fortified with Zn, whereas the milk of preterm infants should be fortified with Fe.