Non-invasive high-frequency oscillatory ventilation (NHFOV) consists of the application of a bias flow generating a continuous distending positive pressure with superimposed oscillations, which have constant frequency and active expiratory phase. NHFOV matches together the advantages of high-frequency ventilation (no need for synchronisation, high efficacy in removing CO 2 ) and nasal continuous positive airway pressure (CPAP) (non-invasive interface, increase in functional residual capacity allowing oxygenation to improve). There is enough clinical expertise demonstrating that NHFOV may be tried in some selected cases, in whom CPAP or conventional non-invasive ventilation have failed. Nonetheless, there are no clear data about its clinical usefulness and there is a need for randomised controlled studies. Our purpose is to review the physiology and biological effects of NHFOV, to present the current clinical evidence on its use, to provide some guiding principles to clinicians and suggest directions for further research.

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AIMSThe use of topiramate, which is prescribed for the management of epilepsy, for migraine headache prophylaxis and as a weight-loss agent, has been associated with the development of metabolic acidosis, hypokalaemia and renal stone disease. We systematically reviewed all the literature. METHODSThe systematic review of the literature was realized using the principles underlying the UK Economic and Social Research Council guidance on the conduct of narrative synthesis and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. RESULTSFourty-seven reports published between 1996 and 2013 were retained for the final analysis. Five case-control studies and six longitudinal studies addressed the effect of topiramate on acid-base and potassium balance. A significant tendency towards mild-to-moderate hyperchloraemic metabolic acidosis (with bicarbonate ≤21.0 mmol l −1 in approximately every third case) and mild hypokalaemia (with potassium ≤3.5 mmol l −1 in 10% of the cases) was noted on treatment with topiramate, which was similar in children and adults. A single study observed that topiramate causes mild hyperuricaemia in male adults. A tendency towards hypocitraturia, a recognized promoter of renal stone formation, was noted in all patients on topiramate. CONCLUSIONSIncreasing evidence supports the use of topiramate. Topiramate is generally well tolerated, and serious adverse events are rare. Nonetheless, the present systematic review of the literature indicates that its use is linked with the development of acidosis, hypokalaemia, hyperuricaemia and hypocitraturia.

Pressure transmission during minimally invasive surfactant administration is significantly reduced or totally absent. Pressure drop occurs despite the increased airway resistances and the airflow limitation due to the tracheal catheterization, but is independent from the type of pressure generator and interface.

Background and Objective Ventilator‐associated pneumonia (VAP) is a common nosocomial infection in critical care settings and might have important long‐term consequences in neonates. Our aim is to clarify the short‐ and long‐term respiratory outcomes of neonates affected by VAP. Methods Prospective, population‐based, cohort study with 12 months follow‐up based on clinical examinations and diary‐based respiratory morbidity score, conducted in an academic tertiary referral neonatal unit with dedicated follow‐up program. Results A total of 199 inborn neonates consecutively ventilated for at least 48 hours were eligible for the study. One hundred fifty‐one were finally enrolled and classified as “exposed” or “unexposed” to VAP, if they fulfilled (or not) VAP criteria once during their stay. Bronchopulmonary dysplasia (BPD) incidence was significantly higher in exposed (75%) than in unexposed babies (26.8%; relative risk [RR]: 2.8 [1.9‐4.0]; AdjRR: 3.5 [1.002‐12.7]; P = .049; number needed to harm = 2.07), although the composite BPD/mortality did not differ. Exposed patients showed longer intensive care unit stay (87 [43‐116] vs 14 [8‐52] days; St.β = 0.24; P < .0001) and duration of ventilation (15 [10‐25] vs 5 [4‐8] days; St.β = 0.29; P < .0001) than unexposed neonates. Exposed patients also showed less ventilator‐free days (11 [5‐17.7] vs 22 [14‐24] days; St.β = −0.15; P = .05) compared to unexposed. Respiratory infections, use of drugs, rehospitalization for respiratory reasons, home oxygen therapy, their composite outcome, and diary‐based clinical respiratory morbidity score were similar between the cohorts. Conclusion Neonatal VAP seems associated to higher incidence of BPD, longer ventilation, and intensive care stay but it does not affect long‐term respiratory morbidity.

Background Early continuous positive airway pressure (CPAP) and surfactant replacement are effective treatments for neonatal respiratory distress syndrome (RDS). CPAP is the first line in preterm infants needing respiratory support, with surfactant replacement in case of CPAP failure (CPAP‐F). Objectives To analyze incidence and factors associated with CPAP‐F in preterm infants with RDS. Design, Setting and Patients Single‐center retrospective database analysis (2004–2017) of inborn infants, gestational age (GA) 24 + 0/7–31 + 6/7 weeks, not intubated on admission to the neonatal intensive care unit, managed with CPAP. CPAP‐F was defined as intubation and surfactant administration in the first 72 h of life; CPAP success (CPAP‐S) was CPAP alone without need for additional RDS treatments. Demographic, respiratory, and clinical data associated with CPAP‐F were studied using logistic regression analysis. Results A total of 562 infants met the inclusion criteria: 252 (44.8%) were CPAP‐F and 310 (55.2%) were CPAP‐S. The CPAP‐F, compared to CPAP‐S group, had lower GA and birth weight, and were less likely to receive antenatal steroids or to be vaginal births. Logistic regression showed that the fraction of inspired oxygen (FiO2) ≥ 0.23 between 180 and 240 min of life (FiO2 180–240 min) was the strongest factor associated with CPAP‐F (odds ratio: 16.01 [95% confidence interval: 10.34–24.81]). Conclusion FiO2 180–240 min was highly predictive of CPAP‐F in preterm infants. With this model for surfactant administration/CPAP‐F, 11.2% of infants would have unnecessarily received treatment, but importantly, 27.7% would have been treated much earlier, with a potential reduction in air leaks and duration of mechanical ventilation.

Objectives To clarify if nasal mask influences noninvasive high‐frequency oscillatory ventilation (NHFOV) mechanics to optimize the clinical use of nasal mask‐delivered NHFOV. Working Hypothesis Nasal mask may affect the mechanical efficacy of NHFOV. Methodology We designed a physiologic study composed of an in vitro phase aiming to investigate pressure transmission and volume delivery in a bench model of nasal mask‐delivered NHFOV. In a second phase, we measured the leaks in vivo in a series of neonates receiving nasal mask‐delivered NHFOV or other forms of noninvasive respiratory support with same nasal masks. Results In vitro pressure transmission is lower with nasal mask (pressure at the lung [Plung]: 2 [0.8]), than with the endotracheal tube (Plung 9.5 [1.5] cmH2O; P = 0.007). Same applies for volume delivery (Vol: 0.6 [0.2] vs 1.8 [0.5] mL; P = 0.0001). Increasing ventilatory boundaries slowly affects pressure and volume delivery. Ventilating the model with maximal parameters (∆P = 55 cmH2O; frequency = 8 Hz) we obtained a Vol 1.5 (0.2) mL. The nasal mask provides lower volume delivery and ventilation, compared with nasal prongs studied in previously published studies. Changing frequency allows a better performance than changing ∆P. In vivo leaks are approximately 30% and are similar during NHFOV or other forms of nasal mask‐delivered noninvasive ventilation. Conclusions Nasal mask‐delivered NHFOV is feasible, but it may require more aggressive ventilatory parameters to increase volume delivery and ventilation. The use of the nasal mask is associated with some leaks, but this is independent from the type of noninvasive respiratory support applied.

We describe herein a case of metabolic acidosis in the setting of treatment with the deferasirox. Our case and the literature indicate a potential risk of kidney toxicity on this agent.