Regional respiratory time constants during lung recruitment in high-frequency oscillatory ventilated preterm infants

To assess the regional respiratory time constants of lung volume changes during stepwise lung recruitment before and after surfactant treatment in high-frequency oscillatory ventilated preterm infants. A stepwise oxygenation-guided recruitment procedure was performed before and after surfactant treatment in high-frequency oscillatory ventilated preterm infants. Electrical impedance tomography was used to continuously record changes in lung volume during the recruitment maneuver. Time constants were determined for all incremental and decremental pressure steps, using one-phase exponential decay curve fitting. Data were analyzed for the whole cross section of the chest and the ventral and dorsal lung regions separately. Before surfactant treatment, the time constants of the incremental pressure steps were significantly longer (median 27.3 s) than those in the decremental steps (16.1 s). Regional analysis showed only small differences between the ventral and dorsal lung regions. Following surfactant treatment, the time constants during decremental pressure steps almost tripled to 44.3 s. Furthermore, the time constants became significantly (p <0.01) longer in the dorsal (61.2 s) than into the ventral (40.3 s) lung region. Lung volume stabilization during stepwise oxygenation-guided lung recruitment in high-frequency oscillatory ventilated preterm infants with respiratory distress syndrome is usually completed within 5 min and is dependent on the position of ventilation on the pressure volume curve, the surfactant status, and the region of interest of the lun

Influence of neonatal endotracheal tube dimensions on oscillometry-acquired reactance:a bench study

Objective: To examine the influence of the endotracheal tube (ETT) on respiratory reactance (Xrs) measured with the forced oscillation technique (FOT) and develop a correction method for it.Approach: In a bench study, the reactance of ETTs (Xtube) with different dimensions was measured on a breathing test lung in various respiratory settings.Main results: Xtube can be accurately predicted by a fitted formula, with an R2 of 0.97, with negligible effects due to changes in respiratory pattern and lung volume.Significance: The developed formula offers the ability to measure ETT-independent Xrs values of patients, improving the potential of FOT for lung function testing in mechanically ventilated newborns.</p

Effort and work-of-breathing parameters strongly correlate with increased resistance in an animal model

Background: Effort of Breathing (EOB) calculations may be a reliable alternative to Work of Breathing (WOB) calculations in which Respiratory Inductance Plethysmography (RIP) replaces spirometry. We sought to compare EOB and WOB measurements in a nonhuman primate model of increasing extrathoracic inspiratory resistance simulating upper airway obstruction (UAO).Methods: RIP, spirometry, and esophageal manometry were measured in spontaneously breathing, intubated Rhesus monkeys utilizing 11 calibrated resistors randomly applied for 2-min. EOB was calculated breath-by-breath as Pressure Rate Product (PRP) and Pressure Time Product (PTP). WOB was calculated from the Pressure-Volume curve based on spirometry (WOBSPIR) or RIP flow (WOBRIP).Results: WOB, PRP and PTP showed similar linear increases when exposed to higher levels of resistive loads. When comparing WOBSPIR to WOBRIP, a similar strong correlation was seen for both signals as resistance increased and there were no statistically significant differences.Conclusion: EOB and WOB parameters utilizing esophageal manometry and RIP, independent of spirometry, showed a strong correlation as a function of increasing inspiratory resistance in nonhuman primates. This allows several potential monitoring possibilities for non-invasively ventilated patients or situations where spirometry is not available. Impact: EOB and WOB parameters showed a strong correlation as a function of increasing inspiratory resistance in nonhuman primates.There was a strong correlation between spirometry-based WOB versus RIP-based WOB.To date, it has remained untested as to whether EOB is a reliable alternative for WOB and if RIP can replace spirometry in these measurements.Our results enable additional potential monitoring possibilities for non-invasively ventilated patients or situations where spirometry is not available.Where spirometry is not available, there is no need to apply a facemask post extubation to a spontaneously breathing, non-intubated infant to make objective EOB measurements.</p

Effort and work-of-breathing parameters strongly correlate with increased resistance in an animal model

Background: Effort of Breathing (EOB) calculations may be a reliable alternative to Work of Breathing (WOB) calculations in which Respiratory Inductance Plethysmography (RIP) replaces spirometry. We sought to compare EOB and WOB measurements in a nonhuman primate model of increasing extrathoracic inspiratory resistance simulating upper airway obstruction (UAO).Methods: RIP, spirometry, and esophageal manometry were measured in spontaneously breathing, intubated Rhesus monkeys utilizing 11 calibrated resistors randomly applied for 2-min. EOB was calculated breath-by-breath as Pressure Rate Product (PRP) and Pressure Time Product (PTP). WOB was calculated from the Pressure-Volume curve based on spirometry (WOBSPIR) or RIP flow (WOBRIP).Results: WOB, PRP and PTP showed similar linear increases when exposed to higher levels of resistive loads. When comparing WOBSPIR to WOBRIP, a similar strong correlation was seen for both signals as resistance increased and there were no statistically significant differences.Conclusion: EOB and WOB parameters utilizing esophageal manometry and RIP, independent of spirometry, showed a strong correlation as a function of increasing inspiratory resistance in nonhuman primates. This allows several potential monitoring possibilities for non-invasively ventilated patients or situations where spirometry is not available. Impact: EOB and WOB parameters showed a strong correlation as a function of increasing inspiratory resistance in nonhuman primates.There was a strong correlation between spirometry-based WOB versus RIP-based WOB.To date, it has remained untested as to whether EOB is a reliable alternative for WOB and if RIP can replace spirometry in these measurements.Our results enable additional potential monitoring possibilities for non-invasively ventilated patients or situations where spirometry is not available.Where spirometry is not available, there is no need to apply a facemask post extubation to a spontaneously breathing, non-intubated infant to make objective EOB measurements.</p

Effort and work-of-breathing parameters strongly correlate with increased resistance in an animal model

Background: Effort of Breathing (EOB) calculations may be a reliable alternative to Work of Breathing (WOB) calculations in which Respiratory Inductance Plethysmography (RIP) replaces spirometry. We sought to compare EOB and WOB measurements in a nonhuman primate model of increasing extrathoracic inspiratory resistance simulating upper airway obstruction (UAO).Methods: RIP, spirometry, and esophageal manometry were measured in spontaneously breathing, intubated Rhesus monkeys utilizing 11 calibrated resistors randomly applied for 2-min. EOB was calculated breath-by-breath as Pressure Rate Product (PRP) and Pressure Time Product (PTP). WOB was calculated from the Pressure-Volume curve based on spirometry (WOBSPIR) or RIP flow (WOBRIP).Results: WOB, PRP and PTP showed similar linear increases when exposed to higher levels of resistive loads. When comparing WOBSPIR to WOBRIP, a similar strong correlation was seen for both signals as resistance increased and there were no statistically significant differences.Conclusion: EOB and WOB parameters utilizing esophageal manometry and RIP, independent of spirometry, showed a strong correlation as a function of increasing inspiratory resistance in nonhuman primates. This allows several potential monitoring possibilities for non-invasively ventilated patients or situations where spirometry is not available. Impact: EOB and WOB parameters showed a strong correlation as a function of increasing inspiratory resistance in nonhuman primates.There was a strong correlation between spirometry-based WOB versus RIP-based WOB.To date, it has remained untested as to whether EOB is a reliable alternative for WOB and if RIP can replace spirometry in these measurements.Our results enable additional potential monitoring possibilities for non-invasively ventilated patients or situations where spirometry is not available.Where spirometry is not available, there is no need to apply a facemask post extubation to a spontaneously breathing, non-intubated infant to make objective EOB measurements.</p

Effort and work-of-breathing parameters strongly correlate with increased resistance in an animal model

Background: Effort of Breathing (EOB) calculations may be a reliable alternative to Work of Breathing (WOB) calculations in which Respiratory Inductance Plethysmography (RIP) replaces spirometry. We sought to compare EOB and WOB measurements in a nonhuman primate model of increasing extrathoracic inspiratory resistance simulating upper airway obstruction (UAO).Methods: RIP, spirometry, and esophageal manometry were measured in spontaneously breathing, intubated Rhesus monkeys utilizing 11 calibrated resistors randomly applied for 2-min. EOB was calculated breath-by-breath as Pressure Rate Product (PRP) and Pressure Time Product (PTP). WOB was calculated from the Pressure-Volume curve based on spirometry (WOBSPIR) or RIP flow (WOBRIP).Results: WOB, PRP and PTP showed similar linear increases when exposed to higher levels of resistive loads. When comparing WOBSPIR to WOBRIP, a similar strong correlation was seen for both signals as resistance increased and there were no statistically significant differences.Conclusion: EOB and WOB parameters utilizing esophageal manometry and RIP, independent of spirometry, showed a strong correlation as a function of increasing inspiratory resistance in nonhuman primates. This allows several potential monitoring possibilities for non-invasively ventilated patients or situations where spirometry is not available. Impact: EOB and WOB parameters showed a strong correlation as a function of increasing inspiratory resistance in nonhuman primates.There was a strong correlation between spirometry-based WOB versus RIP-based WOB.To date, it has remained untested as to whether EOB is a reliable alternative for WOB and if RIP can replace spirometry in these measurements.Our results enable additional potential monitoring possibilities for non-invasively ventilated patients or situations where spirometry is not available.Where spirometry is not available, there is no need to apply a facemask post extubation to a spontaneously breathing, non-intubated infant to make objective EOB measurements.</p

Effort and work-of-breathing parameters strongly correlate with increased resistance in an animal model

Background: Effort of Breathing (EOB) calculations may be a reliable alternative to Work of Breathing (WOB) calculations in which Respiratory Inductance Plethysmography (RIP) replaces spirometry. We sought to compare EOB and WOB measurements in a nonhuman primate model of increasing extrathoracic inspiratory resistance simulating upper airway obstruction (UAO).Methods: RIP, spirometry, and esophageal manometry were measured in spontaneously breathing, intubated Rhesus monkeys utilizing 11 calibrated resistors randomly applied for 2-min. EOB was calculated breath-by-breath as Pressure Rate Product (PRP) and Pressure Time Product (PTP). WOB was calculated from the Pressure-Volume curve based on spirometry (WOBSPIR) or RIP flow (WOBRIP).Results: WOB, PRP and PTP showed similar linear increases when exposed to higher levels of resistive loads. When comparing WOBSPIR to WOBRIP, a similar strong correlation was seen for both signals as resistance increased and there were no statistically significant differences.Conclusion: EOB and WOB parameters utilizing esophageal manometry and RIP, independent of spirometry, showed a strong correlation as a function of increasing inspiratory resistance in nonhuman primates. This allows several potential monitoring possibilities for non-invasively ventilated patients or situations where spirometry is not available. Impact: EOB and WOB parameters showed a strong correlation as a function of increasing inspiratory resistance in nonhuman primates.There was a strong correlation between spirometry-based WOB versus RIP-based WOB.To date, it has remained untested as to whether EOB is a reliable alternative for WOB and if RIP can replace spirometry in these measurements.Our results enable additional potential monitoring possibilities for non-invasively ventilated patients or situations where spirometry is not available.Where spirometry is not available, there is no need to apply a facemask post extubation to a spontaneously breathing, non-intubated infant to make objective EOB measurements.</p

Elective induction of labour and expectant management in late-term pregnancy : A prospective cohort study alongside the INDEX randomised controlled trial

Funding Information: BWM reports consultancy for ObsEva. BMW has received research funding from Ferring and Merck. The original RCT was funded by ZonMw: number NTR3431 , Netherlands Trial Registy . BWM is supported by a NHMRC Investigator grant (GNT1176437). Publisher Copyright: © 2022 The AuthorsPeer reviewedPublisher PD

Epidemiology of Neonatal Acute Respiratory Distress Syndrome:Prospective, Multicenter, International Cohort Study

OBJECTIVES: Age-specific definitions for acute respiratory distress syndrome (ARDS) are available, including a specific definition for neonates (the "Montreux definition"). The epidemiology of neonatal ARDS is unknown. The objective of this study was to describe the epidemiology, clinical course, treatment, and outcomes of neonatal ARDS. DESIGN: Prospective, international, observational, cohort study. SETTING: Fifteen academic neonatal ICUs. PATIENTS: Consecutive sample of neonates of any gestational age admitted to participating sites who met the neonatal ARDS Montreux definition criteria. MEASUREMENTS AND MAIN RESULTS: Neonatal ARDS was classified as direct or indirect, infectious or noninfectious, and perinatal (≤ 72 hr after birth) or late in onset. Primary outcomes were: 1) survival at 30 days from diagnosis, 2) inhospital survival, and 3) extracorporeal membrane oxygenation (ECMO)-free survival at 30 days from diagnosis. Secondary outcomes included respiratory complications and common neonatal extrapulmonary morbidities. A total of 239 neonates met criteria for the diagnosis of neonatal ARDS. The median prevalence was 1.5% of neonatal ICU admissions with male/female ratio of 1.5. Respiratory treatments were similar across gestational ages. Direct neonatal ARDS (51.5% of neonates) was more common in term neonates and the perinatal period. Indirect neonatal ARDS was often triggered by an infection and was more common in preterm neonates. Thirty-day, inhospital, and 30-day ECMO-free survival were 83.3%, 76.2%, and 79.5%, respectively. Direct neonatal ARDS was associated with better survival outcomes than indirect neonatal ARDS. Direct and noninfectious neonatal ARDS were associated with the poorest respiratory outcomes at 36 and 40 weeks' postmenstrual age. Gestational age was not associated with any primary outcome on multivariate analyses. CONCLUSIONS: Prevalence and survival of neonatal ARDS are similar to those of pediatric ARDS. The neonatal ARDS subtypes used in the current definition may be associated with distinct clinical outcomes and a different distribution for term and preterm neonates