A non-invasive continuous and real-time volumetric monitoring in spontaneous breathing subjects based on bioimpedance-ExSpiron®Xi: a validation study in healthy volunteers.

Tidal volume (TV) monitoring breath-by-breath is not available at bedside in non-intubated patients. However, TV monitoring may be useful to evaluate the work of breathing. A non-invasive device based on bioimpedance provides continuous and real-time volumetric tidal estimation during spontaneous breathing. We performed a prospective study in healthy volunteers aimed at evaluating the accuracy, the precision and the trending ability of measurements of ExSpiron®Xi as compared with the gold standard (i.e. spirometry). Further, we explored whether the differences between the 2 devices would be improved by the calibration of ExSpiron®Xi with a pre-determined tidal volume. Analysis accounted for the repeated nature of measurements within each subject. We enrolled 13 healthy volunteers, including 5 men and 8 women. Tidal volume, TV/ideal body weight (IBW) and respiratory rate (RR) measured with spirometer (TVSpirometer) and with ExSpiron®Xi (TVExSpiron) showed a robust correlation, while minute ventilation (MV) showed a weak correlation, in both non/calibrated and calibrated steps. The analysis of the agreement showed that non-calibrated TVExSpiron underestimated TVspirometer, while in the calibrated steps, TVExSpiron overestimated TVspirometer. The calibration procedure did not reduce the average absolute difference (error) between TVSpirometer and TVExSpiron. This happened similarly for TV/IBW and MV, while RR showed high accuracy and precision. The trending ability was excellent for TV, TV/IBW and RR. The concordance rate (CR) was >95% in both calibrated and non-calibrated measurements. The trending ability of minute ventilation was limited. Absolute error for both calibrated and not calibrated values of TV, TV/IBW and MV accounting for repeated measurements was variably associated with BMI, height and smoking status. Conclusions: Non-invasive TV, TV/IBW and RR estimation by ExSpiron®Xi was strongly correlated with tidal ventilation according to the gold standard spirometer technique. This data was not confirmed for MV. The calibration of the device did not improve its performance. Although the accuracy of ExSpiron®Xi was mild and the precision was limited for TV, TV/IBW and MV, the trending ability of the device was strong specifically for TV, TV/IBW and RR. This makes ExSpiron®Xi a non-invasive monitoring system that may detect real-time tidal volume ventilation changes and then suggest the need to better optimize the patient ventilatory support.

The Factors Associated With Continuous Positive Airway Pressure (CPAP) Failure in Late Preterm and Term Infants and Its Impact on In-Hospital Outcomes.

Background and objective Late preterm and term infants commonly require continuous positive airway pressure (CPAP) on admission. However, CPAP failure in this population has not been well studied. Hence, we conducted this study to determine the impact of CPAP failure and identify antenatal factors associated with it in late preterm and term infants. Materials and methods We carried out a single-center retrospective analysis of all inborn infants of ≥34 weeks gestational age (GA) from 2012 to 2019 who received CPAP on admission to the neonatal intensive care unit (NICU). CPAP failure was defined as follows: escalation in the mode of respiratory support, surfactant administration, increase in FiO2 >0.2 above the baseline, or absolute FiO2 >0.4 for ≥3h; within 12h of admission. In-hospital outcomes and perinatal factors were compared between CPAP-failure and success groups. Multivariate stepwise binary logistic regression analysis (LRA) was used to assess the association between antenatal factors and CPAP failure.  Results Of the 272 infants included in the study, 38 (14%) failed CPAP. Infants in the failure group received a longer duration of respiratory support [median (IQR): 3.0 (5.6) vs. 0.5 (0.5)d; p<0.001], and length of stay [9 (9) vs. 4 (4)d; p<0.001]. On LRA, higher GA was associated with reduced odds of CPAP failure. Maternal hypertensive disorders, meconium-stained amniotic fluid, and group B Streptococcus (GBS)-positive status were associated with increased odds of CPAP failure. Conclusions In this cohort of late preterm and term infants, CPAP failure was associated with worse in-hospital outcomes. Lower GA, maternal hypertensive disorders, meconium-stained amniotic fluid, and GBS-positive status were associated with CPAP failure. These data, if replicated in further studies, may help develop individualized respiratory support strategies.

Development of personalized non-invasive ventilation masks for critically ill children: a bench study.

BACKGROUND: Obtaining a properly fitting non-invasive ventilation (NIV) mask to treat acute respiratory failure is a major challenge, especially in young children and patients with craniofacial abnormalities. Personalization of NIV masks holds promise to improve pediatric NIV efficiency. As current customization methods are relatively time consuming, this study aimed to test the air leak and surface pressure performance of personalized oronasal face masks using 3D printed soft materials. Personalized masks of three different biocompatible materials (silicone and photopolymer resin) were developed and tested on three head models of young children with abnormal facial features during preclinical bench simulation of pediatric NIV. Air leak percentages and facial surface pressures were measured and compared for each mask. RESULTS: Personalized NIV masks could be successfully produced in under 12 h in a semi-automated 3D production process. During NIV simulation, overall air leak performance and applied surface pressures were acceptable, with leak percentages under 30% and average surface pressure values mostly remaining under normal capillary pressure. There was a small advantage of the masks produced with soft photopolymer resin material. CONCLUSION: This first, proof-of-concept bench study simulating NIV in children with abnormal facial features, showed that it is possible to obtain biocompatible, personalized oronasal masks with acceptable air leak and facial surface pressure performance using a relatively short, and semi-automated production process. Further research into the clinical value and possibilities for application of personalized NIV masks in critically ill children is needed.

Management of neonates with respiratory distress syndrome in resource-limited settings.

In South Africa, prematurity stands as one of the foremost causes of neonatal mortality. A significant proportion of these deaths occur because of respiratory distress syndrome of prematurity. The implementation of non-invasive respiratory support, such as continuous positive airway pressure (CPAP), has demonstrated both safety and efficacy in reducing mortality rates and decreasing the need for mechanical ventilation. Given the absence of blood gas analysers and limited radiological services in many district hospitals, the severity of respiratory distress is often assessed through observation of the infant's work of breathing and the utilisation of bedside scoring systems. Based on the work of breathing, non-invasive therapy can be commenced timeously. While evidence supporting the use of high-flow nasal cannula as a primary treatment for respiratory distress syndrome remains limited, it may be considered as an alternative, provided that CPAP machines are available. The purpose of this article is to advocate the use of non-invasive therapy in low resource-limited settings and describe the indications, contraindications, complications, and application of CPAP therapy. This would benefit healthcare workers, especially in low-care settings and district hospitals.

In Vivo Measurement of Tidal Volume During Non-invasive Respiratory Support by Continuous-Flow Helmet CPAP.

Recently, the interest in the Helmet interface during non-invasive respiratory support (NIRS) has increased due to the COVID-19 pandemic. During NIRS, positive end-expiratory pressure (PEEP) can be given as continuous positive airway pressure (CPAP), which maintains a positive airway pressure throughout the whole respiratory cycle with Helmet as an interface (H-CPAP). The main disadvantage of the H-CPAP is the inability to measure tidal volume (VT). Opto-electronic plethysmography (OEP) is a non-invasive technique that is not sensitive to gas compression/expansion inside the helmet. OEP acquisitions were performed on 28 healthy volunteers (14 females and 14 males) at baseline and during Helmet CPAP. The effect of posture (semi-recumbent vs. prone), flow (50 vs. 60 L/min), and PEEP (0 vs. 5 vs. 10 cmH2O) on the ventilatory and thoracic-abdominal pattern and the operational volumes were investigated. Prone position limited vital capacity, abdominal expansion and chest wall recruitment. A constant flow of 60 L/min reduced the need for the subject to ventilate while having a slight recruitment effect (100 mL) in the semi-recumbent position. A progressive increasing recruitment was found with higher PEEP but limited by the prone position. It is possible to accurately measure tidal volume during H-CPAP to deliver non-invasive ventilatory support using opto-electronic plethysmography during different clinical settings.

RAM Cannula versus Short Binasal Prongs for Non-invasive Ventilation in Preterm Infants: An Updated Systematic Review and Meta-analysis.

OBJECTIVES: To compare the efficacy and safety of RAM cannula with short binasal prongs (SBPs) as nasal interfaces in preterm infants requiring nasal continuous positive airway pressure (nCPAP) or nasal intermittent positive pressure ventilation (NIPPV). METHODS: The authors searched electronic databases (Medline, Embase, and Web of Science) and trial registries from inception until March 15, 2024, for randomized controlled trials (RCTs) comparing the RAM cannula with SBP for delivering nCPAP/NIPPV. They performed a random-effects meta-analysis using RevMan 5.4 software. The primary outcome was failure of nCPAP/NIPPV. Secondary outcomes included nasal injury, mechanical ventilation, air leaks, and mortality. RESULTS: Five RCTs (825 participants) were included. There was no significant difference in nCPAP/NIPPV failure (RR: 1.04; 95% CI: 0.58 to 1.87) or the need for invasive mechanical ventilation (RR: 1.23; 95% CI: 0.75 to 2.01) between the RAM cannula and SBP groups (low to very low certainty). Compared with infants in the SBP group, those in the RAM cannula group had a significantly lower incidence of moderate to severe nasal injury [(5 RCTs, 825 participants; RR: 0.34; 95% CI: 0.18 to 0.66); low certainty] and any nasal injury [(RR: 0.44; 95% CI: 0.26 to 0.76; very low certainty)]. There was no significant difference in the other clinical outcomes. CONCLUSIONS: In comparison to SBP, the RAM cannula may have little to no effect on nCPAP/NIPPV failure, but the evidence is very uncertain. Low-certainty evidence suggests that the use of RAM cannula possibly results in reduction in moderate to severe nasal trauma in preterm infants receiving nCPAP/NIPPV.

The Diaphragmatic Initiated Ventilatory Assist (DIVA) trial: study protocol for a randomized controlled trial comparing rates of extubation failure in extremely premature infants undergoing extubation to non-invasive neurally adjusted ventilatory assist versus non-synchronized nasal intermittent positive pressure ventilation.

BACKGROUND: Invasive mechanical ventilation contributes to bronchopulmonary dysplasia (BPD), the most common complication of prematurity and the leading respiratory cause of childhood morbidity. Non-invasive ventilation (NIV) may limit invasive ventilation exposure and can be either synchronized or non-synchronized (NS). Pooled data suggest synchronized forms may be superior. Non-invasive neurally adjusted ventilatory assist (NIV-NAVA) delivers NIV synchronized to the neural signal for breathing, which is detected with a specialized catheter. The DIVA (Diaphragmatic Initiated Ventilatory Assist) trial aims to determine in infants born 240/7-276/7 weeks' gestation undergoing extubation whether NIV-NAVA compared to non-synchronized nasal intermittent positive pressure ventilation (NS-NIPPV) reduces the incidence of extubation failure within 5 days of extubation. METHODS: This is a prospective, unblinded, pragmatic, multicenter phase III randomized clinical trial. Inclusion criteria are preterm infants 24-276/7 weeks gestational age who were intubated within the first 7 days of life for at least 12 h and are undergoing extubation in the first 28 postnatal days. All sites will enter an initial run-in phase, where all infants are allocated to NIV-NAVA, and an independent technical committee assesses site performance. Subsequently, all enrolled infants are randomized to NIV-NAVA or NS-NIPPV at extubation. The primary outcome is extubation failure within 5 days of extubation, defined as any of the following: (1) rise in FiO2 at least 20% from pre-extubation for > 2 h, (2) pH ≤ 7.20 or pCO2 ≥ 70 mmHg; (3) > 1 apnea requiring positive pressure ventilation (PPV) or ≥ 6 apneas requiring stimulation within 6 h; (4) emergent intubation for cardiovascular instability or surgery. Our sample size of 478 provides 90% power to detect a 15% absolute reduction in the primary outcome. Enrolled infants will be followed for safety and secondary outcomes through 36 weeks' postmenstrual age, discharge, death, or transfer. DISCUSSION: The DIVA trial is the first large multicenter trial designed to assess the impact of NIV-NAVA on relevant clinical outcomes for preterm infants. The DIVA trial design incorporates input from clinical NAVA experts and includes innovative features, such as a run-in phase, to ensure consistent technical performance across sites. TRIAL REGISTRATION: www. CLINICALTRIALS: gov , trial identifier NCT05446272 , registered July 6, 2022.

Analysis of predictors of response to high-flow oxygen nasal cannula therapy in a pediatric intensive care unit / Análisis de factores predictores de respuesta a la oxigenoterapia de alto flujo en una unidad de cuidados intensivos pediátricos

Abstract Background: Bronchiolitis is one of the most frequent reasons for admission to pediatric intensive care units. Medical treatment is primarily supportive. The usefulness of high-flow oxygen (HFO) nasal cannula in these patients has been described. This study evaluated the clinical and analytical variables of patients admitted to our Pediatric Intensive Care Unit (PICU) for initiation or continuation of HFO for respiratory distress and to identify any variable that may be a predictor of success or failure of this technique. Methods: We conducted a retrospective observational study that included infants aged < 24 months admitted to our PICU due to bronchiolitis between January 2015 and March 2019 for HFO. Results: We analyzed the characteristics between responders (n = 112) and non-responders (n = 37). No statistically significant differences were observed between groups regarding sex, age, weight, comorbidities, nasopharyngeal aspirate result, hours of evolution, and respiratory and heart rate. However, a pCO2 ≥ 75 mmHg (p = 0.043) and a SCORE of bronchiolitis severity (p = 0.032) were predictors of HFNC failure. Conclusions: The pCO2 level and SCORE of bronchiolitis severity are predictors of this respiratory support modality.

Resumen Introducción: La bronquiolitis es uno de los motivos más frecuentes de ingreso en las Unidades de Cuidados Intensivos Pediátricos (UCIP); el tratamiento médico es básicamente de soporte. Se ha descrito la utilidad de la oxigenoterapia de alto flujo (OAF) en estos pacientes. El objetivo de este estudio fue evaluar algunas variables clínicas y analíticas de los pacientes que ingresan en nuestra UCIP para inicio o continuación de OAF ante cuadros de dificultad respiratoria e identificar cualquier variable que pueda ser factor predictor del éxito o fracaso de esta técnica. Métodos: Se realizó un estudio retrospectivo observacional, incluyendo lactantes menores de 24 meses ingresados en la UCIP entre enero de 2015 y marzo de 2019 para OAF ante cuadros de bronquiolitis. Resultados: Se analizaron las características entre el grupo de respondedores (n = 112) y no respondedores (n = 37). No se observaron diferencias estadísticamente significativas en cuanto al sexo, edad, peso, comorbilidades, resultado del aspirado naso-faríngeo, horas de evolución, frecuencia respiratoria, frecuencia cardiaca entre ambos grupos. Sin embargo, una pCO2 ≥75 mmHg (p = 0.043) y un SCORE de gravedad de la bronquiolitis mayor (p = 0.032) fueron factores predictores de fracaso de la OAF. Conclusiones: El nivel de pCO2 y el SCORE de gravedad de la bronquiolitis son factores predictores de esta modalidad de soporte respiratorio.