Relationship between Mean Airways Pressure, Lung Mechanics, and Right Ventricular Output during High-Frequency Oscillatory Ventilation in Infants

Objective To characterize changes in lung mechanics and right ventricular output (RVO) during incremental/decremental continuous distending pressure (CDP) maneuvers in newborn infants receiving high-frequency oscillatory ventilation, with the aim of evaluating when open lung maneuvers are needed and whether they are beneficial. Study design Thirteen infants on high-frequency oscillatory ventilation were studied with a median (IQR) gestational age of 261 (253-291) weeks and median (IQR) body weight of 810 (600-1020) g. CDP was increased stepwise from 8 cmH2O to a maximum pressure and subsequently decreased until oxygenation deteriorated or a CDP of 8 cmH2O was reached. The lowest CDP that maintained good oxygenation was considered the clinically optimal CDP. At each CDP, the following variables were evaluated: oxygenation, respiratory system reactance (Xrs), and RVO by Doppler echocardiography. Results At maximal CDP reached during the trial, 19 [1] cmH2O (mean [SEM]), oxygenation markedly improved, and Xrs and RVO decreased. During deflation, oxygenation remained stable over a wide range of CDP settings, Xrs returned to the baseline values, and RVO increased but the baseline values were not readily restored in all patients. Conclusion These results suggest that Xrs and RVO are more sensitive than oxygenation to overdistension and they may be useful in clinical practice to guide open lung maneuvers

Effect of continuous positive airway pressure on breathing variability in early preterm lung disease

Objectives: In preterm infants, the application of nasal Continuous Positive Airway Pressure (nCPAP) improves lung function through several mechanisms and may interact with the control of breathing. Our aim was to evaluate the effect of increasing/decreasing nCPAP on gas exchange, breathing pattern, and its variability in preterm infants. Methods: Fifeteen infants with mild to moderate respiratory distress syndrome (RDS) were studied on the first day of life. Infants had a mean (SD) gestational age of 30+4 (3+4) weeks+day and body weight of 1405 (606)g. nCPAP was increased every 10min stepwise (0-4-8-10cmH2O) and then decreased every 20min (8-6-4-2cmH2O). At each step, vital parameters, oxygenation, and chest wall volume changes (optoelectronic plethysmography) were evaluated. Tidal volume (VT), inter-breath interval (IBI), end-expiratory lung volume (EELV) changes, and other breathing pattern parameters were computed breath-by-breath. The correlation properties of VT, IBI, and EELV were quantified by detrended fluctuation analysis, computing the scaling exponent α. Results: During nCPAP, oxygenation improved and VTdecreased significantly compared with no nCPAP. No significant changes in breathing pattern were observed between nCPAP levels. α of EELV was significantly higher off nCPAP than during nCPAP, suggesting that nCPAP helps stabilize EELV control mechanisms. Conclusions: In our population of preterm infants with mild to moderate RDS, in the first day of life, nCPAP improved gas exchange, VT, and EELV stability independent of nCPAP level

The eye involvement in monogenic autoinflammatory diseases: Literature review and update

Monogenic autoinflammatory diseases (AIDs) are rare entities characterised by improper activation of the innate immune system. This in turn determines recurrent episodes of systemic inflammation characterised by fever, which is variously combined with a wide range of inflammatory manifestations involving the skin, joints, serous membranes, gastrointestinal tract, and central nervous system. As shown by research efforts conducted during the last decade, the eye is not exempt from the systemic inflammatory process and may be involved in almost all of the most frequent AIDs, with several distinct peculiarities. Ocular affections may severely impact patients' quality of life due to orbital pain, impairment of visual acuity, and/ or long-term, sight-threatening complications. Consequently, in the context of a multidisciplinary team, ophthalmologists should be aware of ocular manifestations related to these disorders as they may have a dominant diagnostic weight in patients with a challenging presentation as well as a salient role in therapeutic choice in sight-threatening situations. This review describes a variety of aspects of ophthalmologic involvement in AIDs, looking at both well-recognised eye manifestations as well as rarely reported ocular presentations, with a particular focus on the recent literature

Timing of uveitis onset in oligoarticular juvenile idiopathic arthritis (JIA) is the main predictor of severe course uveitis

Aim of the present study was to validate a statistical model to predict a severe course of anterior uveitis (AU) in patients with juvenile idiopathic arthritis (JIA). Methods:  Consecutive patients with newly diagnosed uveitis have been followed for at least 1 year with a standardized protocol. For each patient, demographic, clinical and laboratory characteristics, including time interval between arthritis and uveitis onset, α2-globulins level at arthritis onset, number of uveitis relapses/year, ocular complications and therapy and visual acuity, have reported. The validation procedure included the assessment of sensitivity, specificity and efficiency of previously published statistical model (Zulian et al. J Rheumatol 2002; 29: 2446–2453) in a new inception cohort of patients during a short length follow-up. Results:  Sixty patients with JIA, followed at 14 paediatric rheumatology–ophthalmology centres in Italy, entered the study. The mean age at arthritis onset was 4.4 years (range 1.2–15.8 years), and the mean interval time between arthritis and uveitis onset was 1.8 years (range: 0.0–14.2 years). After the first AU, patients, followed for a mean of 3.2 years, had a mean of 2.9 uveitis relapses. Twenty-two patients (36.7%) presented at least one complication. Using a probability cut-off value = 0.7, the statistical model revealed 80% sensitivity, 58% specificity and 65% efficiency. Conclusion:  The time interval between arthritis and uveitis onset resulted as the main predictor of severe course uveitis in JIA. The statistical model was able to predict the development of a severe course in 8 of 10 patients

Comparable Efficacy of Abatacept Used as First-line or Second-line Biological Agent for Severe Juvenile Idiopathic Arthritis-related Uveitis

OBJECTIVE: Abatacept (ABA) has recently been proposed as second-line treatment in patients with juvenile idiopathic arthritis (JIA)-associated uveitis refractory to anti-tumor necrosis factor-\u3b1 (anti-TNF) agents, but little is known about its efficacy as a first-line approach. The aim of the present study was to compare the safety and efficacy of ABA as a first-line biological agent (ABA-1) with that of ABA as a second-line treatment after 1 or more anti-TNF agents (ABA-2), in patients with severe JIA-related uveitis. METHODS: In this multicenter study, we collected data on patients with severe JIA-related uveitis treated with ABA as a first-line or second-line biological agent. Changes in frequency of uveitis flares/year and ocular complications before and after ABA treatment, clinical remission, and side effects were recorded. RESULTS: Thirty-five patients with a mean age of 10.8 years were treated with ABA for a mean period of 19.6 months. In 4 patients, ABA administration was discontinued, owing to inefficacy on arthritis in 3 cases and allergic reaction in 1. Thirty-one patients, 14 in the ABA-1 group and 17 in the ABA-2 group, completed the 12-month followup period; of these, 17 (54.8%) had clinical remission. The mean frequency of uveitis flares decreased from 4.1 to 1.2 in the ABA-1 group (p = 0.002) and from 3.7 to 1.2 in the ABA-2 group (p = 0.004). Preexisting ocular complications improved or remained stable in all but 5 patients, all in the ABA-2 group. No significant difference was found between the efficacy of the 2 treatment modalities. ABA confirmed its good safety profile. CONCLUSION: ABA, used as first-line biological treatment or after 1 or more anti-TNF agents, induces a comparable improvement in severe refractory JIA-related uveitis

Safety and Efficacy of Infliximab and Adalimumab for Refractory Uveitis in Juvenile Idiopathic Arthritis: 1-year Followup Data from the Italian Registry

Objective. To evaluate safety and efficacy of adalimumab (ADA) and infliximab (IFX) for the treatment of juvenile idiopathic arthritis-related anterior uveitis (JIA-AU). Methods. Starting January 2007, patients with JIA-AU treated with IFX and ADA were managed by a standard protocol and data were entered into the National Italian Registry (NIR). At baseline, all patients were refractory to standard immunosuppressive treatment and/or were cortico - steroid-dependent. Data recorded every 3 months included uveitis course, number/type of ocular complications, drug-related adverse events (AE), treatment change or withdrawal, and laboratory measures. Data of patients treated for at least 1 year were retrieved from the NIR and analyzed using descriptive statistics. Treatment efficacy was based on change in uveitis course and in number of ocular complications. Results. Up to December 2009, data for 108 patients with JIA-AU treated with anti-tumor necrosis factor-agents were recorded in the NIR and data from 91, with at least 12 months’ followup, were included in the study. Forty-eight patients were treated with IFX, 43 with ADA. Forty-seven patients (55.3%) achieved remission of AU, 28 (32.9%) had recurrent AU, and 10 (11.8%) maintained a chronic course. A higher remission rate was observed with ADA (67.4% vs 42.8% with IFX; p = 0.025). Ocular complications decreased from 0.47 to 0.32 per subject. Five patients experienced resolution of structural complications. No patient reported serious AE; 8 (8.8%) experienced 11 minor AE (9 with IFX, 2 with ADA). Conclusion. IFX and ADA appear to be effective and safe for treatment of refractory JIA-related uveitis, with a better performance of ADA in the medium-term period

Intratracheal atomized surfactant provides similar outcomes as bolus surfactant in preterm lambs with respiratory distress syndrome

Background:Aerosolization of exogenous surfactant remains a challenge. This study is aimed to evaluate the efficacy of atomized poractant alfa (Curosurf) administered with a novel atomizer in preterm lambs with respiratory distress syndrome.Methods:Twenty anaesthetized lambs, 127 ± 1 d gestational age, (mean ± SD) were instrumented before birth and randomized to receive either (i) positive pressure ventilation without surfactant (Control group), (ii) 200 mg/kg of bolus instilled surfactant (Bolus group) at 10 min of life or (iii) 200 mg/kg of atomized surfactant (Atomizer group) over 60 min from 10 min of life. All lambs were ventilated for 180 min with a standardized protocol. Lung mechanics, regional lung compliance (electrical impedance tomography), and carotid blood flow (CBF) were measured with arterial blood gas analysis.Results:Dynamic compliance and oxygenation responses were similar in the Bolus and Atomizer groups, and both better than Control by 180 min (all P < 0.05; two-way ANOVA). Both surfactant groups demonstrated more homogeneous regional lung compliance throughout the study period. There were no differences in CBFConclusion:In a preterm lamb model, atomized surfactant resulted in similar gas exchange and mechanics as bolus administration. This study suggests evaluation of supraglottic atomization with this system when noninvasive support is warranted

Optimal mean airway pressure during high-frequency oscillatory ventilation determined by measurement of respiratory system reactance.

The aims of the present study were (i) to characterize the relationship between mean airway pressure (PAW) and reactance measured at 5 Hz (reactance of the respiratory system (X RS), forced oscillation technique) and (ii) to compare optimal PAW (P opt) defined by X RS, oxygenation, lung volume (VL), and tidal volume (VT) in preterm lambs receiving high-frequency oscillatory ventilation (HFOV).Nine 132-d gestation lambs were commenced on HFOV at PAW of 14 cmH2O (P start). PAW was increased stepwise to a maximum pressure (P max) and subsequently sequentially decreased to the closing pressure (Pcl, oxygenation deteriorated) or a minimum of 6 cmH2O, using an oxygenation-based recruitment maneuver. X RS, regional V L (electrical impedance tomography), and V T were measured immediately after (t 0 min) and 2 min after (t 2 min) each PAW decrement. P opt defined by oxygenation, X RS, V L, and V T were determined.The PAW-X RS and PAW-VT relationships were dome shaped with a maximum at Pcl+6 cmH2O, the same point as P opt defined by VL. Below Pcl+6 cmH2O, X RS became unstable between t 0 min and t 2 min and was associated with derecruitment in the dependent lung. P opt, as defined by oxygenation, was lower than the P opt defined by X RS, V L, or V T.X RS has the potential as a bedside tool for optimizing PAW during HFOV

Effect of frequency on pressure cost of ventilation and gas exchange in newborns receiving high-frequency oscillatory ventilation

BackgroundWe 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.MethodsWe 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.ResultsBlood 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.ConclusionThere 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.Pediatric Research advance online publication, 26 July 2017; doi:10.1038/pr.2017.151