Sustained Inflation Research Articles

Sustained Inflation of Infant Lungs: From Bench to Bedside and Back Again.

Sustained Inflation of Infant Lungs: From Bench to Bedside and Back Again.

Sustained lung inflation does not decrease bronchopulmonary dysplasia or death among extremely preterm infants: A Commentary on The SAIL randomised clinical trial.

The CONSORT guidelines allow for meaningful assessment of how randomised controlled trials have been designed, analysed and reported, and a thorough evaluation of a RCT within the context of these guidelines allows for fair interpretation of the data presented.1 Title and abstract sections of the article identifies the trial as a randomised trial and includes a structured summary of trial design, method, result and conclusion.2 The introduction section includes the scientific background, rationale as well as specific objectives of whether sustained lung inflation at birth reduces bronchopulmonary dysplasia (BPD) or death which is a relevant topic as the rates of BPD remain high.3 Method section describes the trial design (parallel-group trial with permuted block randomisation), eligibility criteria, settings and locations of participants. There were no critical changes in the method after starting the trial. Interventions to each group and outcomes, both primary and secondary, were defined in sufficient detail. The sample size was calculated to detect absolute risk reduction of death or BPD by 12.5% with 80% power and 2-sided α = 0.038 (adjusted P-value for two planned interim analyses). The authors had pre-specified planned interim analysis and stopping rules. Computer-generated parallel-group randomisation was done, and the trial was not blinded. Statistical analysis, for primary and secondary analyses, as well as subgroup analyses and sensitivity analyses were robust. Flow diagram accounting for all enrolled infants was presented. The investigators planned to recruit 600 infants but trial was stopped early after recruiting 426 infants as predefined secondary safety endpoint was met when the data and safety monitoring committee reported suggestion of higher death in the sustained inflation group within the first 48 hours of life compared to control group (7.4% vs 1.4% aRD, 5.6% [95% CI, 2.1% to 9.1%]; P = .002). Baseline characteristics of the two groups were comparable. Primary outcomes death or BPD at 36 weeks, as well as death and BPD at 36 weeks, were not different between the groups. There were no significant differences in secondary outcomes. The discussion section mentions the limitations of the article. The article does not report the comparative outcomes between the centres where sustained lung inflation was routine versus the centres where the procedure was investigational. These findings would be meaningful because the familiarity of the procedure may change the outcomes. The trial is registered in clinicaltrials.gov, the full protocol is available, and funding information is provided. Previous trials to evaluate the efficacy and effectiveness of sustained lung inflation on preterm infants that enrolled preterm infants of different gestational age and birth weight have shown the inconsistent result in short-term outcomes.4-6 Animal studies have shown an inverse relationship between gestational age and lung aeration from sustained lung inflation,7 so the response to sustained inflation may vary with the size and gestational age of an infant. The SAIL trial performed well under CONSORT assessment and concluded that sustained lung inflation should not be used in this patient population. https://ebneo.org/2019/07/sustained-lung-inflation-bpd/ None.

Gestational Age Influences the Early Microarchitectural Changes in Response to Mechanical Ventilation in the Preterm Lamb Lung.

Background: Preterm birth is associated with abnormal lung architecture, and a reduction in pulmonary function related to the degree of prematurity. A thorough understanding of the impact of gestational age on lung microarchitecture requires reproducible quantitative analysis of lung structure abnormalities. The objectives of this study were (1) to use quantitative histological software (ImageJ) to map morphological patterns of injury resulting from delivery of an identical ventilation strategy to the lung at varying gestational ages and (2) to identify associations between gestational age-specific morphological alterations and key functional outcomes.Method: Lung morphology was compared after 60 min of a standardized ventilation protocol (40 cm H2O sustained inflation and then volume-targeted positive pressure ventilation with positive end-expiratory pressure 8 cm H2O) in lambs at different gestations (119, 124, 128, 133, 140d) representing the spectrum of premature developmental lung states and the term lung. Age-matched controls were compared at 124 and 128d gestation. Automated and manual functions of Image J were used to measure key histological features. Correlation analysis compared morphological and functional outcomes in lambs aged ≤128 and >128d.Results: In initial studies, unventilated lung was indistinguishable at 124 and 128d. Ventilated lung from lambs aged 124d gestation exhibited increased numbers of detached epithelial cells and lung tissue compared with 128d lambs. Comparing results from saccular to alveolar development (120–140d), lambs aged ≤124d exhibited increased lung tissue, average alveolar area, and increased numbers of detached epithelial cells. Alveolar septal width was increased in lambs aged ≤128d. These findings were mirrored in the measures of gas exchange, lung mechanics, and molecular markers of lung injury. Correlation analysis confirmed the gestation-specific relationships between the histological assessments and functional measures in ventilated lambs at gestation ≤128 vs. >128d.Conclusion: Image J allowed rapid, quantitative assessment of alveolar morphology, and lung injury in the preterm lamb model. Gestational age-specific patterns of injury in response to delivery of an identical ventilation strategy were identified, with 128d being a transition point for associations between morphological alterations and functional outcomes. These results further support the need to develop individualized respiratory support approaches tailored to both the gestational age of the infant and their underlying injury response.

Interventions for the Management of Respiratory Distress in Late Preterm and Term Infants Experiencing Delayed Respiratory Transition: A Systematic Review.

To examine the best available evidence for interventions used to manage mild to moderate respiratory distress in late preterm and term infants experiencing delayed respiratory transition. EMBASE, MEDLINE, Cochrane Review, Joanna Briggs, PubMed, CINAHL, and Google Scholar online databases were searched for articles related to delayed respiratory transition. Reference lists were reviewed to identify additional articles for inclusion. Randomized, blinded, placebo-controlled, randomized prospective, prospective observational, and retrospective cohort studies published in English-language, peer-reviewed journals between 2007 and August 2017 were reviewed for inclusion. Studies were included if they examined respiratory focused interventions that could potentially prevent admission to the neonatal intensive care unit (NICU) of the term or late preterm infant transitioning to extrauterine life. The CASP tools were utilized for appraisal of individual studies. Data were extracted from the 5 studies included in this review. In 4 of the 5 studies, prevention of NICU admission was the primary aim. The observational study observed videos of newborn resuscitations and described the effect of early intervention with continuous positive-airway pressure (CPAP) ventilation on prevention of NICU admission for respiratory distress. One randomized controlled trial used adrenaline injections to prevent development of respiratory distress. The 3 remaining randomized controlled trials used prophylactic CPAP or sustained inflation as a method for preventing development of delayed respiratory transition. Three of the 5 studies focused exclusively on cesarean born infants. Among the interventions studied, early or prophylactic CPAP shows the most promise for prevention of NICU admission in late preterm and term infants with mild to moderate respiratory distress. The lack of safety and efficacy data for either adrenaline injections or prophylactic CPAP precludes either method for current use in the prevention of respiratory distress for the late preterm or term infant transitioning to extrauterine life. Two randomized trials, both using prophylactic CPAP, had a significant decrease in NICU admissions. Both studies were conducted at a single center and exclusive to infants born by cesarean delivery. A single study using sustained lung inflation showed no significant difference in the need for respiratory support or NICU admission. A single study using adrenaline also showed no benefit to the prevention of respiratory distress related to transition. Further multicenter randomized controlled trials are needed before broad adoption of early or prophylactic CPAP can be recommended.

Erratum: Effects of Sustained Inflation or Positive Pressure Ventilation on the Release of Adrenomedullin in Preterm Infants with Respiratory Failure at Birth.

Objective Delivery room (DR) management may play an important role in the development and prevention of lung injury. Therefore, in a cohort of low birth weight infants (LBW), we investigated the effects of two different lung recruitment maneuvers, such as positive pressure ventilation (PPV) and sustained inflation (SI) on adrenomedullin (AM), a well-established lung-specific vasoactive agent. Study Design This is a prospective case-control randomized study in 44 LBW infants spontaneously breathing with respiratory failure at birth requiring respiratory support. LBW were randomized to receive PPV (n = 22) or SI (n = 22) support. AM was measured from blood in samples collected at birth from arterial artery (BLT0) and at 1-hour (BLT1) and at 24-hour (BLT2) from peripheral venous site. AM assessment in urine samples was performed at 1-hour (URT1) and at 24-hour (URT2). Results No significant differences in AM (p > 0.05) blood (T0–T2) and urine (T1, T2) levels were observed between groups. Conclusion The present data, showing the absence of any differences in AM blood and urine levels, suggest that PPV and SI are both feasible and equally effective DR maneuvers. The findings open the way to further studies evaluating the effects of PPV and SI on short-/long-term respiratory outcome through biomarkers assessment.

Electrical impedance tomography for neonatal ventilation assessment: a narrative review

Neonatal care has improved dramatically over the last decades thanks to a better understanding of the transition to extrauterine life, especially due to the new respiration condition. A privileged technique to assess the filling of the lungs with air in a non-invasive way is Electrical Impedance Tomography (EIT), which is, therefore, also a tool to monitor ventilation. Out of 2427 papers on EIT from 1985 to 2018, 116 deal with EIT in neonatal care, with both the set and subset increasing at similar rates of 5 and 0.4 additional papers per year (0.03 and 0.05 papers per year) respectively. EIT can be used to determine Body position and Pneumothorax, to guide Endotracheal Tube Positioning and to monitor Ventilation Homogeneity. Moreover, real time EIT gives abundant evidence to develop new techniques such as Sustained Inflation, Protective Intended Ventilation, Minimal Invasive Surfactant Therapy, Less Invasive Surfactant Administration, Intubation-Surfactant-Extubation and Oro Pharyngeal Surfactant during their application to both animal models and patients. The low cost, non-invasive and easy graphic interpretation of EIT leads to the belief that it will have widespread use in Neonatal Medicine.

Effects of Sustained Inflation or Positive Pressure Ventilation on the Release of Adrenomedullin in Preterm Infants with Respiratory Failure at Birth.

Delivery room (DR) management may play an important role in the development and prevention of lung injury. Therefore, in a cohort of low birth weight infants (LBW), we investigated the effects of two different lung recruitment maneuvers, such as positive pressure ventilation (PPV) and sustained inflation (SI) on adrenomedullin (AM), a well-established lung-specific vasoactive agent. This is a prospective case-control randomized study in 44 LBW infants spontaneously breathing with respiratory failure at birth requiring respiratory support. LBW were randomized to receive PPV (n = 22) or SI (n = 22) support. AM was measured from blood in samples collected at birth from arterial artery (BLT0) and at 1-hour (BLT1) and at 24-hour (BLT2) from peripheral venous site. AM assessment in urine samples was performed at 1-hour (URT1) and at 24-hour (URT2). No significant differences in AM (p > 0.05) blood (T0-T2) and urine (T1, T2) levels were observed between groups. The present data, showing the absence of any differences in AM blood and urine levels, suggest that PPV and SI are both feasible and equally effective DR maneuvers. The findings open the way to further studies evaluating the effects of PPV and SI on short-/long-term respiratory outcome through biomarkers assessment.

Neonatal Resuscitation: State of the Art.

The objective of this study is to revise novel evidence and forthcoming clinical trials that focused on the gap of knowledge raised during the 2015 guidelines for neonatal resuscitation. Literature search on main topics on neonatal resuscitation published after 2015 edition of the consensus on science and guidelines was performed. Only relevant articles (mainly randomized controlled trials [RCTs] and meta-analyses) were included and presented as descriptive review. In the past years, new RCTs and/or meta-analyses have become available on umbilical cord clamping and umbilical cord milking, oxygen concentrations to start resuscitation in term and preterm infants, use of laryngeal mask, sustained lung inflation, less invasive surfactant administration, and heart rate assessment. Despite the increasing available literature on neonatal resuscitation in the past years, many interventions are still performed without robust scientific evidence. Adequately powered and well-designed RCTs are needed to optimize management of neonates at birth.

IP Litigation in United States District Courts: 1994 to 2014

This article undertakes a broad-based empirical review of Intellectual Property (IP) litigation in United States federal district courts from 1994 to 2014. Unlike the prior literature, this study analyzes federal copyright, patent and trademark litigation trends as a unified whole. It undertakes a systematic analysis of more than 190,000 individual case filings and examines the subject matter, geographical and temporal variation within federal IP litigation over the last two decades. This article makes a number of significant contributions to our understanding of IP litigation. It analyzes time trends in copyright, patent and trademark litigation filings at the national level, but it does much more than simply count the number of cases; it explores the meaning behind those numbers and shows how in some cases the observable headline data can be positively misleading. Exploring the changes in the distribution of IP litigation over time and their regional distribution leads to a number of significant insights, these are summarized below. Just as importantly, one of the key contributions of this article is that it frames the context for more fine-grained empirical studies in the future. Many of the results and conclusions herein demonstrate the dangers of basing empirical conclusions on narrow slices of data from selected regions or selected time periods. Some of the key findings of this study are as follows: First, the rise of Internet file-sharing has transformed copyright litigation in the United States. More specifically, to the extent that the rate of copyright litigation has increased over the last two decades, that increase appears to be entirely attributable to lawsuits against anonymous Internet file sharers. These lawsuits largely took place in two distinct phases: the first phase largely consisted of lawsuits seeking to discourage illegal downloading; the second phase largely consists lawsuits seeking to monetize online infringement. Second, in relation to patent litigation, the apparent patent litigation explosion between 2010 and 2012 is something of a mirage; however there has been a sustained patent litigation inflation over the last two decades the extent of which has not been fully recognized until now. The reason why this steady inflation was mistaken for a sudden explosion was that the true extent of patent litigation was disguised by permissive joinder.Third, in relation to the geography of IP litigation, it appears that filings in copyright, patent and trademark litigation are generally highly correlated. The major exceptions to that correlation are driven by short term idiosyncratic events in copyright and trademark litigation — these are discussed in detail — and by the dumbfounding willingness of the Eastern district Texas to engage in forum selling to attract patent litigation. The popularity of the Eastern District of Texas as a forum for patent litigation is a well-known phenomenon. However, the data and analysis presented in this study provides a new way of looking at the astonishing ascendancy of this district and the problem of form shopping in patent law more generally.

Sustained Lung Inflation With CPAP in Preterm Neonates (SI-CPAP)

Sustained Lung Inflation With CPAP in Preterm Neonates (SI-CPAP)

Neonatal respiratory support strategies for the management of extremely low gestational age infants: an Italian survey

BackgroundWe aimed to survey Delivery Room and Neonatal Intensive Care Unit (NICU) respiratory strategies dedicated to the extremely low gestational age newborn (ELGAN – GA < 28 wks) in Italy.MethodsA questionnaire was sent to 113 Italian level III centres. A lead physician and a nurse with expertise in mechanical ventilation (MV) were identified in each unit to answer. Information about those aspects of ventilatory support considered by center’s staff as needing improvement was also collected.ResultsA 100% response rate was obtained. In the Delivery Room, sustained lung inflation was performed in 74.8% of centres, and 89.2% used NCPAP. For ELGANs who need invasive MV, conventional MV was the most used strategy. Volume-targeted ventilation and High-frequency oscillatory ventilation (HFOV) were considered as primary mode in < 30% of centres. Among non-invasive strategies, NCPAP was the most utilized, followed by BiPAP, High-flow nasal cannula and nasal intermittent positive pressure ventilation. Nurses more commonly recorded in the nursing charts the ventilator’s setting parameters rather than measured ones. HFOV and non-invasive ventilation were the most quoted aspects of neonatal ventilation felt as to be improved.ConclusionThe routine respiratory support practices in Italy showed marked variations among units. Focused interventions are largely required to improve clinical practice.

RETRACTED ARTICLE: The effects of a recruitment manoeuvre with positive end-expiratory pressure on lung compliance in patients undergoing robot-assisted laparoscopic radical prostatectomy

The effects of a recruitment manoeuvre (RM) with positive end-expiratory pressure (PEEP) on lung compliance (CLUNG) are not well characterised in robot-assisted laparoscopic radical prostatectomy (RARP). Patients were allocated to group R (n = 10; with an RM) or C (n = 9; without an RM). An RM involved sustained inflation of 30 cmH2O for 30 s. The lungs were ventilated with volume-controlled ventilation with tidal volume of 7 mL kg−1 of predicted body weight and fraction of inspired oxygen of 0.5. End-tidal carbon dioxide pressure was maintained at normocapnia. Patients were in the horizontal lithotomy position (pre-op). After pneumoperitoneum, patients underwent RARP in a steep Trendelenburg lithotomy position at a PEEP level of 0 cmH2O (RARP0). An RM was used in the R group but not in the C group. Patients were then ventilated with 5 cmH2O PEEP for 1 h after RARP0 (RARP5.1) and 2 h after RARP0 (RARP5.2). Oesophageal pressure and airway pressure were measured for calculating CLUNG and chest wall compliance. CLUNG significantly decreased from pre-op to RARP0 and did not significantly increase from RARP0 to RARP5.1 and RARP5.2 in either group. CLUNG differed significantly between groups at RARP5.1 and RARP5.2 (103 ± 30 vs. 68 ± 11 mL cm−1 H2O and 106 ± 35 vs. 72 ± 9 mL cm−1 H2O; P < 0.05). In patients undergoing RARP, with the addition of RM, the CLUNG was effectively increased from the horizontal lithotomy position to the steep Trendelenburg lithotomy position under pneumoperitoneum.

Sustained Inflation for Delivery Room Resuscitation of Extremely Preterm Infants

At birth, the lung must fill with air and establish functional residual capacity (FRC) to take on its role as the organ of gas exchange. This process

Effect of Sustained Inflations vs Intermittent Positive Pressure Ventilation on Bronchopulmonary Dysplasia or Death Among Extremely Preterm Infants

Preterm infants must establish regular respirations at delivery. Sustained inflations may establish lung volume faster than short inflations. To determine whether a ventilation strategy including sustained inflations, compared with standard intermittent positive pressure ventilation, reduces bronchopulmonary dysplasia (BPD) or death at 36 weeks' postmenstrual age without harm in extremely preterm infants. Unmasked, randomized clinical trial (August 2014 to September 2017, with follow-up to February 15, 2018) conducted in 18 neonatal intensive care units in 9 countries. Preterm infants 23 to 26 weeks' gestational age requiring resuscitation with inadequate respiratory effort or bradycardia were enrolled. Planned enrollment was 600 infants. The trial was stopped after enrolling 426 infants, following a prespecified review of adverse outcomes. The experimental intervention was up to 2 sustained inflations at maximal peak pressure of 25 cm H2O for 15 seconds using a T-piece and mask (n = 215); standard resuscitation was intermittent positive pressure ventilation (n = 211). The primary outcome was the rate of BPD or death at 36 weeks' postmenstrual age. There were 27 prespecified secondary efficacy outcomes and 7 safety outcomes, including death at less than 48 hours. Among 460 infants randomized (mean [SD] gestational age, 25.30 [0.97] weeks; 50.2% female), 426 infants (92.6%) completed the trial. In the sustained inflation group, 137 infants (63.7%) died or survived with BPD vs 125 infants (59.2%) in the standard resuscitation group (adjusted risk difference [aRD], 4.7% [95% CI, -3.8% to 13.1%]; P = .29). Death at less than 48 hours of age occurred in 16 infants (7.4%) in the sustained inflation group vs 3 infants (1.4%) in the standard resuscitation group (aRD, 5.6% [95% CI, 2.1% to 9.1%]; P = .002). Blinded adjudication detected an imbalance of rates of early death possibly attributable to resuscitation (sustained inflation: 11/16; standard resuscitation: 1/3). Of 27 secondary efficacy outcomes assessed by 36 weeks' postmenstrual age, 26 showed no significant difference between groups. Among extremely preterm infants requiring resuscitation at birth, a ventilation strategy involving 2 sustained inflations, compared with standard intermittent positive pressure ventilation, did not reduce the risk of BPD or death at 36 weeks' postmenstrual age. These findings do not support the use of ventilation with sustained inflations among extremely preterm infants, although early termination of the trial limits definitive conclusions. clinicaltrials.gov Identifier: NCT02139800.

Value of Neo-Puff as a tool for Sustained Lung Inflation in Preterm babies

Preterm labor is an obstetrics emergency and a threat to population health. 75% of infant mortality is related to preterm labor, to detect and predict efficacy of Neo-puff as a tool for sustained lung inflation on preterm, 100 preterm children were included in this study, The patients were divided in to 2 groups: Group A: SLI inflation and Group B: assessed as usually. Then the groups were compared regarding their outcome and their need of respiratory assessment. there was a statistical difference between groups regarding need to mechanical ventilator, as 34% of group A and 54% in group B (p=0.035), there was a statistical difference between groups regarding the time of use of mechanical ventilator, the use of mechanical ventilator in the 1st day was higher (46%) in group B, compared to only 14% of group A, p=0.004, there was no statistical difference between groups regarding occurrence of BPD, hospitalization or mortality rate. Sustained lung inflation is easier to perform even with a single operator; it reduces the necessity of mechanical ventilator in the first 72 hours without statistically evident adverse effects. However, did not decrease the need for respiratory support, occurrence of BPD, hospitalization or mortality rate.

The SURV1VE trial\u2014sustained inflation and chest compression versus 3:1 chest compression-to-ventilation ratio during cardiopulmonary resuscitation of asphyxiated newborns: study protocol for a cluster randomized controlled trial

BackgroundThe need for cardiopulmonary resuscitation (CPR) is often unexpected, and the infrequent use of CPR in the delivery room (DR) limits the opportunity to perform rigorous clinical studies to determine the best method for delivering chest compression (CC) to newborn infants. The current neonatal resuscitation guidelines recommend using a coordinated 3:1 compression-to-ventilation (C:V) ratio (CC at a rate of 90/min and ventilations at a rate of 30/min). In comparison, providing CC during a sustained inflation (SI) (CC + SI) significantly improved hemodynamics, minute ventilation, and time to return of spontaneous circulation (ROSC) compared to 3:1 C:V ratio in asphyxiated piglets. Similarly, a small pilot trial in newborn infants showed similar results. Until now no study has examined different CC techniques during neonatal resuscitation in asphyxiated newborn infants in the DR. To date, no trial has been performed to directly compare CC + SI and 3:1 C:V ratio in the DR during CPR of asphyxiated newborn infants.MethodsThis is a large, international, multi-center, prospective, unblinded, cluster randomized controlled trial in asphyxiated newborn infants at birth. All term and preterm infants > 28+ 0 by best obstetrical estimate who require CPR at birth due to bradycardia (< 60/min) or asystole are eligible. The primary outcome of this study is to compare the time to ROSC in infants born > 28+ 0 weeks’ gestational age with bradycardia (< 60/min) or asystole immediately after birth who receive either CC + SI or 3:1 C:V ratio as the CPR strategy.DiscussionMorbidity and mortality rates are extremely high for newborns requiring CC. We believe the combination of simultaneous CC and SI during CPR has the potential to significantly improve ROSC and survival. In addition, we believe that CC + SI might improve respiratory and hemodynamic parameters and potentially minimize morbidity and mortality in newborn infants. In addition, this will be the first randomized controlled trial to examine CC in the newborn period.Trial registrationClinicalTrials.gov, NCT02858583. Registered on 8 August 2016

Aeration strategy at birth influences the physiological response to surfactant in preterm lambs

BackgroundThe influence of pressure strategies to promote lung aeration at birth on the subsequent physiological response to exogenous surfactant therapy has not been investigated.ObjectivesTo compare the effect of sustained inflation...

Effects of SI and PCV on respiratory mechanics, early central drive and hemodynamics in patients with ARDS.

Effects of sustained inflation (SI) and pressure- controlled ventilation (PCV) on respiratory mechanics, early central drive, and hemodynamics in patients with acute respiratory distress syndrome (ARDS) were investigated and compared. A retrospective analysis of 26 patients with ARDS, who were admitted to the Yiwu Central Hospital from March 2015 to March 2016, was performed. According to the ventilation method adopted by the patients with ARDS, 13 patients who received SI treatment were included in the SI group and 13 patients who received PCV treatment were included in the PCV group. The condition of central drive of the patients in the two groups was recorded and calculated continuously before and after recruitment maneuver (RM), the changes of each indicator of the respiratory function and hemodynamics were recorded and calculated before and after RM at 1, 10, 20 and 30 min. The differences were not statistically significant when comparing PIP, Pplate and Crs in patients in the SI group and the PCV group before RM with those after RM at 1, 10, 20 and 30 min (P>0.05), the differences were not statistically significant when comparing heart rate and mean arterial pressure in patients in the SI group and the PCV group before RM with those after RM at 1, 10, 20 and 30 min (P>0.05). Ηowever, central venous pressure in patients in the SI group after RM at 10 and 20 min was significantly higher than that in the PCV group, and the differences were statistically significant (P<0.05). VT/RMS, VE/RMS and ΔPdi/RMS in the SI group and the PCV group after RM were significantly higher than those before RM, and the differences were statistically significant (P<0.05). There was little difference in the effect between SI and PCV on respiratory mechanics, early central drive and hemodynamics in patients with ARDS, and both mechanical ventilation methods enhanced the effect of central-mechanical-ventilation coupling after RM. Therefore, the two mechanical ventilation methods, SI and PCV, were equally available for patients with ARDS.

Comparison of Two Respiratory Support Strategies for Stabilization of Very Preterm Infants at Birth: A Matched-Pairs Analysis

Objective: Respiratory support for stabilizing very preterm infants at birth varies between centers. We retrospectively compared two strategies that involved either increasing continuous positive airway pressures (CPAP), or increasing oxygen supplementation.Methods: Matched-pairs of infants (<28 weeks of gestation) were born either at the Leiden University Medical Center [low-pressure: CPAP 5–8 cmH2O and/or positive pressure ventilation (PPV) and fraction of inspired oxygen (FiO2) 0.3–1.0; n = 27], or at the University Hospital of Cologne (high-pressure: CPAP 12–35 cmH2O, no PPV and FiO2 0.3–0.4; n = 27). Respiratory support was initiated non-invasively via facemask at both units. Infants (n = 54) were matched between centers for gestational age and birth weight, to compare physiological and short-term clinical outcomes.Results: In the low-pressure group, 20/27 (74%) infants received 1–2 sustained inflations (20, 25 cm H2O) and 22/27 (81%) received PPV (1:19–3:01 min) using pressures of 25–27 cm H2O. Within 3 min of birth [median (IQR)], mean airway pressures [12 (6–15) vs. 19 (16–23) cmH2O, p < 0.001] and FiO2 [0.30 (0.28–0.31) vs. 0.22 (0.21–0.30), p < 0.001] were different in low- vs. high-pressure groups, respectively. SpO2 and heart rates were similar. After 3 min, higher FiO2 levels [0.62 (0.35–0.98) vs. 0.28 (0.22–0.38), p = 0.005] produced higher SpO2 levels [77 (50–92) vs. 53 (42–69)%, p < 0.001] in the low-pressure group, but SpO2/FiO2 and heart rates were similar. While intubation rates during admission were significantly different (70 vs. 30%, p = 0.013), pneumothorax rates (4 vs. 19%, p = 0.125) and the occurrence of spontaneous intestinal perforations (0 vs. 15%, p = 0.125) were similar between groups.Conclusion: Infants (<28 weeks) can be supported non-invasively at birth with either higher or lower pressures and while higher-pressure support may require less oxygen, it does not eliminate the need for oxygen supplementation. Future studies need to examine the effect of high pressures and pressure titration in the delivery room.

Lung Recruitment Strategies During High Frequency Oscillatory Ventilation in Preterm Lambs

Background: High frequency oscillatory ventilation (HFOV) is considered a lung protective ventilation mode in preterm infants only if lung volume is optimized. However, whilst a “high lung volume strategy” is advocated for HFOV in preterm infants this strategy is not precisely defined. It is not known to what extent lung recruitment should be pursued to provide lung protection. In this study we aimed to determine the relationship between the magnitude of lung volume optimization and its effect on gas exchange and lung injury in preterm lambs.Methods: 36 surfactant-deficient 124–127 d lambs commenced HFOV immediately following a sustained inflation at birth and were allocated to either (1) no recruitment (low lung volume; LLV), (2) medium- (MLV), or (3) high lung volume (HLV) recruitment strategy. Gas exchange and lung volume changes over time were measured. Lung injury was analyzed by post mortem pressure-volume curves, alveolar protein leakage, gene expression, and histological injury score.Results: More animals in the LLV developed a pneumothorax compared to both recruitment groups. Gas exchange was superior in both recruitment groups compared to LLV. Total lung capacity tended to be lower in the LLV group. Other parameters of lung injury were not different.Conclusions: Lung recruitment during HFOV optimizes gas exchange but has only modest effects on lung injury in a preterm animal model. In the HLV group aiming at a more extensive lung recruitment gas exchange was better without affecting lung injury.