Nasal high-frequency percussive ventilation vs nasal continuous positive airway pressure in newborn infants respiratory distress: A cross over clinical trial.

OBJECTIVE: To determine if nasal high-frequency percussive ventilation (nHFPV) to manage neonatal respiratory distress decreases the regional cerebral oxygen saturation (rScO2 ) compared to nasal continous positive airway pressure (nCPAP). STUDY DESIGN: A prospective, randomized, monocentric, open-label, noninferiority crossover trial. Newborns of gestational age (GA) ≥ 33 weeks exhibiting persistent respiratory distress after 10 minutes of life were treated with nHFPV and nCPAP, in succession and in random order. The primary endpoint was the mean rScO2 , as revealed by near-infrared spectroscopy (NIRS). RESULTS: Forty-nine newborns were randomized; the mean GA and birth weight was 36.4 ± 1.9 weeks and 2718 ± 497 g. The mean rScO2 difference during the last 5 minutes of each ventilation mode (nHFPV minus nCPAP) was -0.7 ± 5.4% (95% confidence interval (CI) -2.25; 0.95%). CONCLUSION: In our study on newborns of GA ≥33 weeks treated for respiratory distress, cerebral oxygenation via nHFPV was not inferior to nCPAP.

An age-wise comparison of human airway smooth muscle proliferative capacity.

We compared the proliferation of neonatal and adult airway smooth muscle cells (ASMC) with no/moderate lung disease, in glucose- (energy production by glycolysis) or glucose-free medium (ATP production from mitochondrial oxidative phosphorylations only), in response to 10% fetal calf serum (FCS) and PDGF-AA. In the presence of glucose, cell counts were significantly greater in neonatal vs. adult ASMC. Similarly, neonatal ASMC DNA synthesis in 10% FCS and PDGF-AA, and [Ca2+]i responses in the presence of histamine were significantly enhanced vs. adults. In glucose-free medium, cell proliferation was preserved in neonatal cells, unlike in adult cells, with concomitant increased porin (an indicator of mitochondrial activity) protein expression. Compared to adults, stimulated neonatal human ASMC are in a rapid and robust proliferative phase and have the capacity to respond disproportionately under abnormal environmental conditions, through increased mitochondrial biogenesis and altered calcium homeostasis.

Nasal high frequency percussive ventilation versus nasal continuous positive airway pressure in transient tachypnea of the newborn: a pilot randomized controlled trial (NCT00556738).

OBJECTIVE: To determine whether nasal high frequency percussive ventilation (NHFPV) would decrease duration of transient tachypnea of the newborn (TTN) compared to nasal continuous positive airway pressure (NCPAP) in newborn infants. METHODS: A prospective, unmasked, randomized, controlled clinical trial was conducted in 46 eligible newborn infants who were hospitalized for TTN in the University Hospital of Bordeaux (France) between 2007 and 2009. Infants born by cesarian section ≥37 GA, ≥2,000 g with diagnosis of TTN and with a transcutaneous saturation <90% at 20 min after birth were eligible. Infants were randomized to either NHFPV or NCPAP. The primary endpoint was a reduction of the duration of TTN. Secondary endpoints were the duration of oxygen therapy and the minimal level required to obtain a saturation between 90% and 96% integrated into an index which included a time factor: [(FiO2 -21)/time of O2 therapy]. RESULTS: In the NHFPV group the duration of TTN was half the time of NCPAP group (105 min ± 20 and 377 min ± 150, respectively; P < 0.0001). There was a significant decrease in duration of oxygen supplementation in the NHFPV group (6.3 min ± 3.3) compared to the NCPAP group (19.1 min ± 8.1; P < 0.001), and a significant decrease in level of oxygen supplementation [(FiO2 -0.21)/time of O2 therapy] in the NHFPV group (0.29 min(-1) ± 0.16) compared to the NCPAP group (0.46 min(-1) ± 0.50; P < 0.001). There was no complication and NHFPV was as well tolerated as NCPAP. CONCLUSION: NHFPV is well tolerated and more effective than NCPAP in treatment of TTN. NHFPV might be a novel and safe tool to manage TTN. Pediatr Pulmonol.

Increased secretion of leukemia inhibitory factor by immature airway smooth muscle cells enhances intracellular signaling and airway contractility.

Airway smooth muscle cells (ASMC) play a major role in airway inflammation, hyperresponsiveness, and obstruction in asthma. However, very little is known regarding the relation between inflammatory mediators and cytokines and immature ASMC. The aim of this study was to evaluate 1) the secretion of leukemia inhibitory factor (LIF) (an IL-6 family neurotrophic cytokine) by ASMC; 2) intracellular calcium concentration ([Ca(2+)](i)) signaling; and 3) the effect of LIF on mast cell chemotaxis and rat airway contractility. Immature and adult human ASMC were cultured. ELISA and real-time PCR were performed to assess LIF protein secretion and mRNA production, [methyl-(3)H]thymidine incorporation to quantify ASMC DNA synthesis, a Boyden chamber to evaluate the effect of LIF on mast cell chemotaxis, microspectroflurimetry using indo-1 (at baseline and after stimulation bradykinin, U-46619, histamine, and acetylcholine, in the presence or absence of LIF or TNF-alpha) for [Ca(2+)](i) signaling, and isolated rat pup tracheae to determine the effect of LIF on airway contractility to ACh. TNF-alpha-stimulated immature ASMC produce more LIF mRNA and protein than adult ASMC, although this cytokine induces a moderate increase in DNA synthesis (+20%) in adult ASMC only. Human recombinant LIF exerts no chemotactic effect on human mast cells. In immature ASMC, ACh-induced [Ca(2+)](i) response was enhanced twofold after incubation with LIF, whereas TNF-alpha increased the [Ca(2+)](i) to U-46619 threefold. In TNF-alpha-exposed adult ASMC, [Ca(2+)](i) responses to ACh were of greater magnitude (sixfold increase) than in immature ASMC. Human recombinant LIF increased contractility to ACh by 50% in immature, isolated rat tracheae. Stimulated immature human ASMC greatly secrete LIF, thus potentially contributing to neuroimmune airway inflammation and subsequent remodeling. Increased LIF secretion enhances airway reactivity and [Ca(2+)](i) signaling.