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We hypothesized that ventilating at the resonant frequency of the respiratory system optimizes gas exchange while limiting the mechanical stress to the lung in newborns receiving high-frequency oscillatory ventilation (HFOV). We characterized the frequency dependence of oscillatory mechanics, gas exchange, and pressure transmission during HFOV. We studied 13 newborn infants with a median (interquartile range) gestational age of 29.3 (26.4–30.4) weeks and body weight of 1.00 (0.84–1.43) kg. Different frequencies (5, 8, 10, 12, and 15 Hz) were tested, keeping carbon dioxide diffusion coefficient (DCO2) constant. Oscillatory mechanics and transcutaneous blood gas were measured at each frequency. The attenuation of pressure swings (ΔP) from the airways opening to the distal end of the tracheal tube (TT) and to the alveolar compartment was mathematically estimated. Blood gases were unaffected by frequency. The mean (SD) resonant frequency was 16.6 (3.5) Hz. Damping of ΔP increased with frequency and with lung compliance. ΔP at the distal end of the TT was insensitive to frequency, whereas ΔP at the peripheral level decreased with frequency. There is no optimal frequency for gas exchange when DCO2 is held constant. Greater attenuation of oscillatory pressure at higher frequencies offers more protection from barotrauma, especially in patients with poor compliance.

The study of respiratory mechanics in infants requires a noninvasive accurate measurement of the lung volume changes (DeltaVL). Optoelectronic plethysmography (OEP) allows the assessment of DeltaVL through the measurement of the chest wall surface motion and it has been proved to be accurate in adults. The aim of this study was to apply OEP to newborns and to validate it by comparison to pneumotachography. Twenty term and preterm newborns (GA = 34 +/- 5 wk) in stable condition were studied during 1 to 2 min periods of quiet breathing in supine position. Airway opening flow was measured by applying a facemask connected to a pneumotachograph (PNT) and integrated to provide the DeltaVL. Chest wall volume changes were simultaneously measured by OEP. The tidal volume values measured by pneumotachography and by OEP were compared for each breath. A total of 771 breaths from all patients were considered. Bland-Altmann analysis showed a mean difference of -0.08 mL and a limit of agreement ranging from -2.98 to 2.83 mL. Linear regression analysis demonstrated good correlation between the two techniques (r = 0.95, q = 1.00 mL, m = 0.96). OEP provides accurate measurements of DeltaVL in newborns and may be useful to study respiratory mechanics and breathing patterns during spontaneous breathing and mechanical ventilation.

During the last few years, advances in the care of low-birth-weight and preterm neonates has stimulated research on the best dietetic program to improve survival and to reduce handicap incidence. At present, fortification of human milk with artificial formulas is the most usual dietetic solution. As yet, however, little is known about the composition of milk from mothers giving birth prematurely. The aim of this study was the quantification of different proteins in human milk during the lactation period. By use of an electrophoretic method, lactoferrin (LF), alpha-lactalbumin, beta-casein, and lysozyme concentrations were measured in milk from mothers delivering normally (TM) or prematurely (PM). LF concentration in milk from TM presented higher values in the very first days and a fast decrease to d 10. After d 10, the concentration reached a plateau. In milk from PM, the LF concentration in the first days was lower than for TM. Similar profiles of alpha-lactalbumin, beta-casein, and lysozyme concentrations were found in milk from TM and PM. A general higher variability in PM samples was observed both between different mothers and for the same woman during the lactation period. Lactation profiles for four human milk proteins are described here. No significant difference was observed (apart from LF in the very first days) between preterm and term milk samples, confirming the unsuitability of unfortified breast milk for preterm neonates.

Several studies have shown that late preterm infants (LPI) are at higher risk for respiratory disorders than term infants. Objective: To evaluate occurrence of respiratory disorders, need for respiratory support, use and timing of specific adjunctive pulmonary therapies in LPI. Methods: Using electronic medical charts, we performed a retrospective analysis of all LPI (34 0/7 to 36 6/7 wks) born from January 2005 to December 2009 in a tertiary level NICU. Results: During the study period, 856/14443 infants born alive were LPI (5.9%). They accounted for 58.9% of preterm births. Majority of LPI were 36 weeks (53.9%), followed by 35 weeks (28.4%) and 34 weeks (17.8%). Transient tachypnea of the newborn (5.8%) was the most common pulmonary illness, followed by respiratory distress syndrome (4.7%), apnea (1.5%), air leak (1.3%) and persistent pulmonary hypertension (0.5%). Composite respiratory morbidity was 12.4%: A total of 69 (8.1%) patients received NCPAP only, 19 (2.2%) mechanical ventilation, 17 (2%) surfactant, 8 (0.9%) chest tube and 4 (0.5%) inhaled nitric oxide. Fig 1 shows the highest levels of respiratory support for each GA. Fig 2 shows times at which each treatment was started. Median length of positive pressure ventilation was 40.5 hours (IQR 16.9-91.6). Mortality was 0.4%. Conclusion: Compared with literature, our population showed lower incidence of mortality, respiratory disorders and need for assisted ventilation, probably due to a great proportion of more mature infants.

This work evaluated the neurodevelopmental and functional outcomes of premature infants with intraventricular hemorrhage (IVH). These outcomes were analyzed for their association with IVH severity. Methods and materials: In the years 2008 and 2009 we performed cerebral ultrasounds of all children with gestational age less than 32 weeks and/or birthweight under 1500 grams. We evaluated the motor outcome (infant cerebral palsy versus normal status) and the neurodevelopmental outcome (Griffith score at 12th month of corrected age) of all children with IVH (classificated according to Papile). Results: In 2008 and 2009 the newborn evaluated were 108 and 90 respectively (both inborn and outborn). Table The correlation between severity of IVH and occurence of PCI was of no statistical significance (p< 0,14). The mean IQ was lower in infants with IVH of first grade than in infants with IVH of second grade or more (101 and 67 respectively). This difference occurred also in all the single items of the Griffith score (106-89-102-102-108 and 61-54-72-68-82 respectively). Conclusions: Even though the difference is not of statistical significance,the PCI is more frequent in infants with severe IVH. The mean IQ correlates with the severity of the IVH. Preventing cerebral hemorrhage may reduce negative long-term outcomes.

Background and aims: HIE severity and MRI findings are predictors of neurological outcome in asphyxiated neonates. Mild hypothermia may reduce the severity of basal ganglia and thalamus lesions, which are predictive of abnormal outcome. Moreover hypothermia does not induce any unexpected cerebral lesions. We compare MRI lesions with HIE grade and neurological outcome. Methods: From December 2006 in S. Gerardo Hospital NICU, mild hypothermia (selective head cooling) is the standard of care for the hypoxicischemic newborns. Patient's selection and treatment were done according to the protocols employed in the published randomized trials. The treated neonates were 26, 12 infants had hypoxicischemic encephalopathy (HIE) grade II and 14 had HIE grade III. MRI (T1-T2 and diffusion-weighted sequences) was performed within 15 days of life and classified according to the Mercury's classification. The neurological outcome was assessed at 12 months. Results: MRI showed cerebral lesions in 71% (mostly mild). Unexpected MRI lesions weren't seen. There is no correlation between severity of HIE and MRI lesions; moreover there is not correlation between the severity of MRI cerebral lesions and motor delay or cerebral palsy. Conclusions: in our population of cooled infants, neurological outcome is not associated with the degree of HIE and the severity of MRI lesions.

Background and aim: Optoelectronic plethysmography (OEP) allows the measurement of lung volume changes through the assessment of chest wall surface motion. It has been shown that it provides an accurate estimation of total and compartmental (rib cage and abdomen) lung volume changes in adults during spontaneous breathing and mechanical ventilation and in spontaneously breathing infants (REF). The aim of the present study is to evaluate the accuracy of OEP in infants during continuous positive airways pressure (CPAP). Methods: 5 infants (GA=27.9±3.6, PNA=3.8±3.6, BW=1077±461) were studied for ∼ 2 minutes at CPAP 0, 4 and 8 cmH2O. Flow was measured at the inlet of a full-face mask by a mesh-type pneumotacograph connected to a differential pressure transducer. Chest wall volume changes were measured by OEP (DVOEP) and compared with lung volume changes obtained by integrating the flow signal (DVPNT). Results: We analysed a total of 602 breaths at 0 cmH2O, 523 at 4 cmH2O, and 150 at 8 cmH2O. The mean difference between DVOEP and DVPNT for all newborns was -0.45±3.92% of Vt at 0 cm H2O, -4.25±9.04% at 4 cmH2O and -8.31±3.87% at 8 cmH2O. Pooling data points from all infants and all pressure levels, Bland-Altman and linear regression analysis showed good agreement between the two measurement techniques (see Fig). Conclusions: OEP can be used to assess lung volume changes and breathing pattern noninvasively in newborns supported by CPAP.

Several cases of fetal intraventricular hemorrage (IVH) have been reported using prenatal ultrasonography (US). However the clinical and prognostic significance of these lesions has not been established. To this aim, four cases of fetal IVH are presented. Methods: US was performed with a high resolution, real-time scanner with a 5.0 Mhz-phased array. MRI studies were obtained using T1 and T2 weighted sections at 4-5 mm intervals.

To confirm the hypothesis that I modifies G pharmacokinetic with high risk of toxicity, we studied 48 neonates (mean gestational age (GA) 28.3 w., birth-weight 1125 g, postnatal age 4.5 d.) affected by respiratory problems and treated with following schedule ol G administration: 2.5 mg(Kg/dose every 24 h for GA