Comparison of neurally adjusted ventilatory assist and synchronized intermittent mandatory ventilation in preterm infants after patent ductus arteriosus ligation: a retrospective study.

OBJECTIVE: This study aimed to compare the efficacy of neurally adjusted ventilatory assist (NAVA) to synchronized intermittent mandatory ventilation (SIMV) in preterm infants requiring mechanical ventilation after patent ductus arteriosus (PDA) ligation. METHODS: A retrospective analysis was conducted on intubated preterm infants who underwent PDA ligation at our hospital from July 2021 to January 2023. Infants were divided into NAVA or SIMV groups based on the ventilation mode after surgery. RESULTS: Fifty preterm infants were included. During treatment, peak inspiratory pressure (PIP) and mean airway pressure (MAP) were lower with NAVA compared to SIMV (PIP: 19.1 ± 2.9 vs. 22.4 ± 3.6 cmH2O, P < 0.001; MAP: 9.1 ± 1.8 vs. 10.9 ± 2.7 cmH2O, P = 0.002). PaO2 and PaO2/FiO2 were higher with NAVA (PaO2: 94.0 ± 11.7 vs. 84.8 ± 15.8 mmHg, P = 0.031; PaO2/FiO2: 267 [220-322] vs. 232 [186-290] mmHg, P = 0.025). Less sedation was required with NAVA (midazolam: 1.5 ± 0.5 vs. 1.1 ± 0.3 µg/kg/min, P < 0.001). CONCLUSION: Compared to SIMV, early use of NAVA post PDA ligation in preterm infants was associated with decreased PIP and MAP. Early NAVA was also associated with reduced sedation needs and improved oxygenation. However, further studies are warranted to quantify the benefits of NAVA ventilation.

High-flow nasal cannula (HFNC) vs continuous positive airway pressure (CPAP) vs nasal intermittent positive pressure ventilation as primary respiratory support in infants of ≥ 32 weeks gestational age (GA): study protocol for a three-arm multi-center randomized controlled trial.

BACKGROUND: Health problems in neonates with gestational age (GA) ≥ 32 weeks remain a major medical concern. Respiratory distress (RD) is one of the common reasons for admission of neonates with GA ≥ 32 weeks. Noninvasive ventilation (NIV) represents a crucial approach to treat RD, and currently, the most used NIV modes in neonatal intensive care unit include high-flow nasal cannula (HFNC), continuous positive airway pressure (CPAP), and nasal intermittent positive pressure ventilation. Although extensive evidence supports the use of NIPPV in neonates with a GA < 32 weeks, limited data exist regarding its effectiveness in neonates with GA ≥ 32 weeks. Therefore, the aim of this study is to compare the clinical efficacy of HFNC, CPAP, and NIPPV as primary NIV in neonates with GA ≥ 32 weeks who experience RD. METHODS: This trial is designed as an assessor-blinded, three-arm, multi-center, parallel, randomized controlled trial, conducted in neonates ≥ 32 weeks' GA requiring primary NIV in the first 24 h of life. The neonates will be randomly assigned to one of three groups: HFNC, CPAP or NIPPV group. The effectiveness, safety and comfort of NIV will be evaluated. The primary outcome is the occurrence of treatment failure within 72 h after enrollment. Secondary outcomes include death before discharge, surfactant treatment within 72 h after randomization, duration of both noninvasive and invasive mechanical ventilation, duration of oxygen therapy, bronchopulmonary dysplasia, time to achieve full enteral nutrition, necrotizing enterocolitis, duration of admission, cost of admission, air leak syndrome, nasal trauma, and comfort score. DISCUSSION: Currently, there is a paucity of data regarding the utilization of NIPPV in neonates with GA ≥ 32 weeks. This study will provide clinical evidence for the development of respiratory treatment strategies in neonates at GA ≥ 32 weeks with RD, with the aim of minimizing the incidence of tracheal intubation and reducing the complications associated with NIV. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR2300069192. Registered on March 9, 2023, https://www.chictr.org.cn/showproj.html?proj=171491 .

Nonsynchronized nasal intermittent positive pressure ventilation versus continuous positive airway pressure as a primary mode of respiratory support in neonates (26-40 weeks) admitted in a tertiary care center: A randomized controlled trial.

INTRODUCTION: Continuous positive airway pressure (CPAP) is a standard respiratory care for neonates for last few decades but it too has a high failure rate. Nasal intermittent positive pressure ventilation (NIPPV) is proven to be superior to CPAP in maintaining higher mean airway pressure in neonates with Respiratory Distress Syndrome. The main objective of this study was to compare failure within 72 h of initiation of primary respiratory support between nonsynchronized NIPPV and CPAP in all causes of respiratory distress in newborn infants. Secondarily feed intolerance, Necrotizing enterocolitis (NEC > stage II), hemodynamically significant patent ductus arteriosus, intraventricular hemorrhage (IVH > gradeIII), retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), duration of support and mortality were also compared. METHODS: This was a single center randomized controlled trial. Stratified randomization was done for 216 neonates, based on the gestational age in two subgroups 26-33 weeks and 34-40 weeks whopresented with respiratory distress within 5 days of birth, to receive either NIPPV or CPAP. Primary and secondary outcomes were documented. RESULTS: Statisticalsignificant difference was noted for primary outcome (RR 0.48 [confidence interval = 0.301-0.786], p = 0.003) but not for other secondary outcomes. NIPPV appeared superior in respect to noninvasiveventilation days, BPD occurrence and hospitalization duration. CONCLUSION: As a primary mode, nonsynchronized NIPPV was more efficacious than CPAP in preventing intubation within 72 h of initiation of respiratory support. Further multicenter studies are warranted to explore the benefits of this respiratory support.

Effectiveness of Nasal Continuous Positive Airway Pressure vs Nasal Intermittent Positive Pressure Ventilation vs Noninvasive High-Frequency Oscillatory Ventilation as Support After Extubation of Neonates Born Extremely Preterm or With More Severe Respiratory Failure: A Secondary Analysis of a Randomized Clinical Trial.

Importance: The NASONE (Nasal Oscillation Post-Extubation) trial showed that noninvasive high-frequency oscillatory ventilation (NHFOV) slightly reduces the duration of invasive mechanical ventilation (IMV) in preterm infants, whereas NHFOV and noninvasive intermittent positive pressure ventilation (NIPPV) result in fewer reintubations than nasal continuous positive airway pressure (NCPAP). It is unknown whether NHFOV is similarly effective in extremely preterm neonates or in those with more severe respiratory failure (based on the duration of previous ventilation and CO2 levels). Objective: To clarify whether NHFOV is better than NIPPV and NCPAP in reducing the duration of IMV in extremely preterm neonates or those with severe respiratory failure. Design, Setting, and Participants: This study is a predefined secondary analyses of a multicenter randomized clinical trial that was performed at tertiary academic neonatal intensive care units (NICUs) in China. Participants included neonates enrolled in the NASONE trial between December 2017 and May 2021 and belonging to 3 predefined subgroups: (1) born at less than or equal to 28 weeks' (plus 6 days) gestation, (2) invasively ventilated for more than 1 week from birth, and (3) with CO2 greater than 50 mm Hg before or in the 24 hours after extubation. Data analysis was performed in August 2022. Intervention: NCPAP, NIPPV, or NHFOV since the first extubation and until NICU discharge, with airway pressure higher in NHFOV than in NIPPV and than in NCPAP. Main Outcomes and Measures: The co-primary outcomes were total duration of IMV during the NICU stay, need for reintubation, and ventilator-free days calculated as per the original trial protocol. Outcomes were analyzed on an intention-to-treat basis as for the whole trial, and subgroup analyses followed the original statistical plan. Results: Among 1137 preterm infants, 455 (279 boys [61.3%]) were born at 28 weeks' gestation or less, 375 (218 boys [58.1%]) underwent IMV for more than 1 week from birth, and 307 (183 boys [59.6%]) had CO2 greater than 50 mm Hg before or in the 24 hours after extubation. Both NIPPV and NHFOV were associated with significantly fewer reintubations (risk difference range, -28% [95% CI, -39% to -17%] to -15% [95% CI, -25% to -4%]; number needed to treat, 3-7 infants) and early reintubations (risk difference range, -24% [95% CI, -35% to -14%] to -20% [95% CI, -30% to -10%]) than NCPAP, and these reintubations were less frequently due to refractory hypoxemia. IMV was shorter in the NIPPV and NHFOV groups (mean difference range, -5.0 days [95% CI, -6.8 to -3.1 days] to -2.3 days [95% CI, -4.1 to -0.4 days]) than in the NCPAP group. Co-primary outcomes were not different between NIPPV and NHFOV; there was no significant interaction effect. Infants in the NHFOV group showed significantly less moderate-to-severe bronchopulmonary dysplasia than infants in the NCPAP group (range, -12% to -10%; number needed to treat, 8-9 infants) and better postextubation gas exchange in all subgroups. The 3 interventions were provided at different mean airway pressure and were equally safe. Conclusions and Relevance: The subgroup analyses of extremely preterm or more ill infants confirm the results obtained in the whole population: NIPPV and NHFOV appeared equally effective in reducing duration of IMV compared with NCPAP. Trial Registration: ClinicalTrials.gov Identifier: NCT03181958.

High continuous positive airway pressures versus non-invasive positive pressure ventilation in preterm neonates: protocol for a multicentre pilot randomised controlled trial.

INTRODUCTION: Low pressure nasal continuous positive airway pressure (nCPAP) has long been the mainstay of non-invasive respiratory support for preterm neonates, at a constant distending pressure of 5-8 cmH2O. When traditional nCPAP pressures are insufficient, other modes including nasal intermittent positive pressure ventilation (NIPPV) are used. In recent years, high nCPAP pressures (≥9 cmH2O) have also emerged as an alternative. However, the comparative benefits and risks of these modalities remain unknown. METHODS AND ANALYSIS: In this multicentre pilot randomised controlled trial, infants <29 weeks' gestational age (GA) who either: (A) fail treatment with traditional nCPAP or (B) being extubated from invasive mechanical ventilation with mean airway pressure ≥10 cmH2O, will be randomised to receive either high nCPAP (positive end-expiratory pressure 9-15 cmH2O) or NIPPV (target mean Paw 9-15 cmH2O). Primary outcome is feasibility of the conduct of a larger, definitive trial as assessed by rates of recruitment and protocol violations. The main secondary outcome is failure of assigned treatment within 7 days postrandomisation. Multiple other clinical outcomes including bronchopulmonary dysplasia will be ascertained. All randomised participants will be analysed using intention to treat. Baseline and demographic variables as well as outcomes will be summarised and compared using univariate analyses, and a p<0.05 will be considered significant. ETHICS AND DISSEMINATION: The trial has been approved by the respective research ethics boards at each institution (McMaster Children's Hospital: Hamilton integrated REB approval #2113; Royal Alexandra Hospital: Health Research Ethics Board approval ID Pro00090244; Westmead Hospital: Human Research Ethics Committee approval ID 2022/ETH01343). Written, informed consent will be obtained from all parents/guardians prior to study enrolment. The findings of this pilot study will be disseminated via presentations at national and international conferences and via publication in a peer-reviewed journal. Social media platforms including Twitter will also be used to generate awareness. TRIAL REGISTRATION NUMBER: NCT03512158.

Supporting all breaths versus supporting some breaths during synchronised mechanical ventilation in neonates: a systematic review and meta-analysis.

BACKGROUND: National Institute for Health and Clinical Effectiveness (NICE), UK, guideline published in 2019 recommends the use of volume-targeted ventilation (VTV). It recommends synchronised intermittent mandatory ventilation (SIMV) over the modes that support-all-breaths, for example, assist control ventilation (ACV). We conducted a systematic review and meta-analysis of the studies comparing SIMV mode with triggered modes supporting all breaths. METHODS: Patients: Neonates receiving mechanical ventilation. INTERVENTION: SIMV ventilation.Comparison: Modes that support-all-breaths: ACV, pressure support ventilation and neurally adjusted ventilation. OUTCOMES: Death before discharge and bronchopulmonary dysplasia (BPD) at 36 weeks' corrected gestation, weaning duration, incidence of air leaks, extubation failure, postnatal steroid use, patent ductus arteriosus requiring treatment, severe (grade 3/4) intraventricular haemorrhage, periventricular leukomalacia and neurodevelopmental outcome at 2 years.Randomised or quasi-randomised clinical trials comparing SIMV with triggered ventilation modes supporting all breaths in neonates, reporting on at least one outcome of interest were eligible for inclusion in the review. RESULTS: Seven publications describing eight studies fulfilled the eligibility criteria. No significant difference in mortality (OR 0.74, 95% CI 0.32 to 1.74) or BPD at 36 weeks (OR 0.63, 95% CI 0.33 to 1.24), but the weaning duration was significantly shorter in support-all-breaths group with a mean difference of -22.67 hours (95% CI -44.33 to -1.01). No difference in any other outcomes. CONCLUSION: Compared with SIMV, synchronised modes supporting all breaths are associated with a shorter weaning duration with no statistically significant difference in mortality, BPD at 36 weeks or other outcomes. Larger studies with explicit ventilator and weaning protocols are needed to compare these modes in the current neonatal population. PROSPERO REGISTRATION NUMBER: The review was prospectively registered with PROSPERO: CRD42020207601.

Changes in dead space components during pressure-controlled inverse ratio ventilation: A secondary analysis of a randomized trial.

BACKGROUND: We previously reported that there were no differences between the lung-protective actions of pressure-controlled inverse ratio ventilation and volume control ventilation based on the changes in serum cytokine levels. Dead space represents a ventilation-perfusion mismatch, and can enable us to understand the heterogeneity and elapsed time changes in ventilation-perfusion mismatch. METHODS: This study was a secondary analysis of a randomized controlled trial of patients who underwent robot-assisted laparoscopic radical prostatectomy. The inspiratory to expiratory ratio was adjusted individually by observing the expiratory flow-time wave in the pressure-controlled inverse ratio ventilation group (n = 14) and was set to 1:2 in the volume-control ventilation group (n = 13). Using volumetric capnography, the physiological dead space was divided into three dead space components: airway, alveolar, and shunt dead space. The influence of pressure-controlled inverse ratio ventilation and time factor on the changes in each dead space component rate was analyzed using the Mann-Whitney U test and Wilcoxon's signed rank test. RESULTS: The physiological dead space and shunt dead space rate were decreased in the pressure-controlled inverse ratio ventilation group compared with those in the volume control ventilation group (p < 0.001 and p = 0.003, respectively), and both dead space rates increased with time in both groups. The airway dead space rate increased with time, but the difference between the groups was not significant. There were no significant changes in the alveolar dead space rate. CONCLUSIONS: Pressure-controlled inverse ratio ventilation reduced the physiological dead space rate, suggesting an improvement in the total ventilation/perfusion mismatch due to improved inflation of the alveoli affected by heterogeneous expansion disorder without hyperinflation of the normal alveoli. However, the shunt dead space rate increased with time, suggesting that atelectasis developed with time in both groups.

Sustained Inflation Versus Intermittent Positive Pressure Ventilation for Preterm Infants at Birth: Respiratory Function and Vital Sign Measurements.

OBJECTIVE: To characterize respiratory function monitor (RFM) measurements of sustained inflations and intermittent positive pressure ventilation (IPPV) delivered noninvasively to infants in the Sustained Aeration of Infant Lungs (SAIL) trial and to compare vital sign measurements between treatment arms. STUDY DESIGN: We analyzed RFM data from SAIL participants at 5 trial sites. We assessed tidal volumes, rates of airway obstruction, and mask leak among infants allocated to sustained inflations and IPPV, and we compared pulse rate and oxygen saturation measurements between treatment groups. RESULTS: Among 70 SAIL participants (36 sustained inflations, 34 IPPV) with RFM measurements, 40 (57%) were spontaneously breathing prior to the randomized intervention. The median expiratory tidal volume of sustained inflations administered was 5.3 mL/kg (IQR 1.1-9.2). Significant mask leak occurred in 15% and airway obstruction occurred during 17% of sustained inflations. Among 34 control infants, the median expiratory tidal volume of IPPV inflations was 4.3 mL/kg (IQR 1.3-6.6). Mask leak was present in 3%, and airway obstruction was present in 17% of IPPV inflations. There were no significant differences in pulse rate or oxygen saturation measurements between groups at any point during resuscitation. CONCLUSION: Expiratory tidal volumes of sustained inflations and IPPV inflations administered in the SAIL trial were highly variable in both treatment arms. Vital sign values were similar between groups throughout resuscitation. Sustained inflation as operationalized in the SAIL trial was not superior to IPPV to promote lung aeration after birth in this study subgroup. TRIAL REGISTRATION: Clinicaltrials.gov: NCT02139800.

Repeated intermittent hypoxic stimuli to operative lung reduce hypoxemia during subsequent one-lung ventilation for thoracoscopic surgery: A randomized controlled trial.

BACKGROUND: An intervention to potentiate hypoxic pulmonary vasoconstriction may reduce intrapulmonary shunt and hypoxemia during one-lung ventilation. Previous animal studies reported that repeated intermittent hypoxic stimuli potentiated hypoxic pulmonary vasoconstriction, but no clinical study has examined the effects of this intervention on hypoxemia during one-lung ventilation. We thus performed a single-center, parallel-group, double-blind, randomized controlled trial to investigate whether repeated intermittent hypoxic stimuli to the operative lung reduce hypoxemia during the subsequent one-lung ventilation for thoracoscopic surgery. METHODS: Patients undergoing one-lung ventilation were randomized into two groups (n = 68 each). Before one-lung ventilation, in the intermittent hypoxia group, the nondependent lung was not ventilated for 2 min and then ventilated for 2 min while the dependent lung was continuously ventilated. This was repeated five times. In the continuous normoxia group, both lungs were ventilated for 20 min. We measured SpO2, PaO2, FiO2, PaCO2, SaO2, and central venous oxygen saturation during one-lung ventilation. The primary outcome was the number of patients with hypoxemia defined as a SpO2 <95% during one-lung ventilation, which was analyzed with a chi-squared test. RESULTS: Hypoxemia was less frequent in the intermittent hypoxia group than in the continuous normoxia group during OLV [6/68 (8.8%) vs 17/68 (25.0%), risk ratio (95% CI) 0.35 (0.15-0.84), p = 0.012]. The PaO2 (p = 0.008 for 30 min and 0.007 for 60 min) and PaO2/FiO2 (p = 0.008 for both) were higher 30 and 60 min after starting one-lung ventilation, and the alveolar-arterial pressure gradient (p = 0.010) and shunt index (p = 0.008) were lower 30 min after starting one-lung ventilation in the intermittent hypoxia group than in the continuous normoxia group. Postoperative adverse events did not differ significantly between groups. CONCLUSIONS: Repeated intermittent hypoxic stimuli to the operative lung seemed to potentiate hypoxic pulmonary vasoconstriction, and thus reduced hypoxemia during the subsequent one-lung ventilation.

Synchronized Nasal Intermittent Positive Pressure Ventilation versus Nasal Continuous Positive Airway Pressure for Prevention of Extubation Failure in Infants after Congenital Heart Surgery.

OBJECTIVE: This study aimed to evaluate the application of synchronized nasal intermittent positive pressure ventilation (SNIPPV) in the respiratory weaning of infants after congenital heart surgery. METHODS: We retrospectively analyzed the clinical data of 63 infants who were extubated from mechanical ventilation after congenital heart surgery between January 2020 and September 2020. The data, including demographics, anatomic diagnosis, radiology and laboratory test results, and perioperative variables were recorded. RESULTS: The extubation failure rate within 48 h after extubation was significantly lower in the SNIPPV group than in the nasal continuous positive airway pressure (NCPAP) group. The PaO2 level and PaO2/FiO2 ratio within 48 h after extubation were higher in the SNIPPV group than in the NCPAP group (P < .05). Meanwhile, the PaCO2 level within 48 h was significantly lower in the SNIPPV group (P < .05). Compared with the NCPAP group, the median duration of postoperative noninvasive support and the duration from extubation to hospital discharge were shorter in the SNIPPV group; the total hospital cost was lower in the SNIPPV group. No significant differences were observed between the two groups concerning VAP, pneumothorax, feeding intolerance, sepsis, mortality, and other complications (P > .05). CONCLUSION: SNIPPV was shown to be superior to NCPAP in avoiding reintubation after congenital heart surgery in infants and significantly improved oxygenation and reduced PaCO2 retention after extubation. Further studies are needed to confirm the efficacy and safety of SNIPPV as a routine weaning strategy.

Spontaneous pneumomediastinum, pneumopericardium, pneumothorax and subcutaneous emphysema in patients with COVID-19 pneumonia, a case report.

BACKGROUND: Spontaneous pneumomediastinum unrelated to mechanical ventilation is a newly described complication of COVID-19 pneumonia. The objective of this case presentation is to highlight an important complication and to explore potential predisposing risk factors and possible underlying pathophysiology of this phenomenon. CASE PRESENTATION: We present two patients with COVID-19 pneumonia complicated by spontaneous pneumomediastinum, pneumopericardium, pneumothorax and subcutaneous emphysema without positive pressure ventilation. Both patients had multiple comorbidities, received a combination of antibiotics, steroids and supportive oxygen therapy, and underwent routine laboratory workup. Both patients then developed spontaneous pneumomediastinum and ultimately required intubation and mechanical ventilation, which proved to be challenging to manage. CONCLUSIONS: Spontaneous pneumomediastinum is a serious complication of COVID-19 pneumonia, of which clinicians should be aware. Further studies are needed to determine risk factors and laboratory data predictive of development of spontaneous pneumomediastinum in COVID-19 pneumonia.

Effect of pressure rise time on ventilator parameters and gas exchange during neonatal ventilation.

BACKGROUND: Pressure rise time (PRT), also known as slope time to the peak inflating pressure can be set on some modern neonatal ventilators. On other ventilators, PRT is determined by the set circuit flow. Changing slope time can affect mean airway pressure (MAP), oxygenation, and carbon dioxide elimination. Our aim was to investigate the effect of PRT on ventilator parameters and gas exchange during volume-guaranteed ventilation. METHODS: In a crossover study, 12 infants weighing greater than 2 kg were ventilated using a Dräger Babylog VN500 ventilator with synchronized intermittent positive pressure ventilation with volume guarantee (SIPPV-VG) and pressure support ventilation with volume guarantee (PSV-VG). During both modes PRTs between 0.08 and 0.40 seconds were used in 15-minute epochs. Data from the ventilator and patient monitors were downloaded with 1- and 100-Hz sampling rate and analyzed using the Python computer language. RESULTS: During PSV-VG, longer PRTs were associated with longer inspiratory time (P < .0001) and with lower peak inflating pressure (PIP; P = .003), but the MAP was similar. During SIPPV-VG the PIP was not significantly different; however, MAP was lower with longer PRT (P = .001). With a short PRT (0.08 seconds), the PIP was higher during PSV-VG than during SIPPV-VG (19.8 vs 16.5 mbar; P = .042). There were no significant differences in tidal volume delivery, respiratory rate, minute volume, oxygen saturations, or end-tidal CO2 with different PRTs in either mode. CONCLUSIONS: During SIPPV-VG or PSV-VG, using short or long PRTs affects some ventilation parameters but does not significantly change oxygenation or carbon dioxide elimination.

Comparing the insertion and ventilation of laryngeal mask airway according to the patient's head position and muscle relaxation use. A prospective clinical trial.

OBJECTIVES: To assess the insertion and ventilation of the laryngeal mask airway (LMA) classic while using different head positions with or without muscle relaxant. METHODS: This is a double-blind randomized clinical trial. Patients scheduled for ureteral calculus surgery at Shanghai General Hospital, Shanghai, China were recruited between November 2017 and November 2018. A total of 132 adults were consecutively selected. Patients were randomly divided into 4 groups according to head positioning and muscle relaxant use. An 8-cm-high pillow was used to achieve the sniffing position. The insertion time, initial peak pressure (Ppeak), mean pressure (Pmean) of the airway during intermittent positive pressure ventilation (primary endpoint) and fiberoptic score of the LMA position (secondary endpoint) were evaluated via electronic bronchoscopy through the mask bar. All adverse events were recorded. Results: Data were analyzed by ANOVA, 2-way ANOVA, Chi-squared, Cochran-Mantel-Haenszel, and Kruskal-Wallis tests. The insertion time required for the first attempt, fiberoptic score, Ppeak and Pmean did not differ among the groups. However, the incidence of adverse events in groups not using muscle relaxant was higher than in those using muscle relaxant. Conclusion: Use of a sniffing position and muscle relaxant slightly eased the insertion of the LMA but did not affect the fiberoptic score or ventilation parameters. Using a muscle relaxant, but not the sniffing position, reduced the incidence of adverse effects.

Nasal Intermittent Mandatory Ventilation Versus Nasal Continuous Positive Airway Pressure Before and After Invasive Ventilatory Support.

Continuous positive airway pressure (CPAP), noninvasive intermittent positive pressure ventilation (NIPPV), and heated humidified high-flow nasal cannula (HHFNC) are modes of noninvasive respiratory support used in neonatal practice. These modes of noninvasive respiratory support may obviate mechanical ventilation, prevent extubation failure, and reduce the risk of developing bronchopulmonary dysplasia. Although the physiologic bases of CPAP and HHFNC are well delineated, and their modes and practical application consistent, those of NIPPV are unproven and varied. Available evidence suggests that NIPPV is superior to CPAP as a primary and postextubation respiratory support in preterm infants.

An observational, prospective, multicenter study on rescue high-frequency oscillatory ventilation in neonates failing with conventional ventilation.

BACKGROUND: To achieve gas exchange goals and mitigate lung injury, infants who fail with conventional ventilation (CV) are generally switched to high-frequency oscillatory ventilation (HFOV). Although preferred in many neonatal intensive care units (NICUs), research on this type of rescue HFOV has not been reported recently. METHODS: An online registry database for a multicenter, prospective study was set to evaluate factors affecting the response of newborn infants to rescue HFOV treatment. The study population consisted of 372 infants with CV failure after at least 4 hours of treatment in 23 participating NICUs. Patients were grouped according to their final outcome as survived (Group S) or as died or received extracorporeal membrane oxygenation (ECMO) (Group D/E). Patients' demographic characteristics and underlying diseases in addition to their ventilator settings, arterial blood gas (ABG) analysis results at 0, 1, 4, and 24 hours, type of device, ventilation duration, and complications were compared between groups. RESULTS: HFOV as rescue treatment was successful in 58.1% of patients. Demographic and treatment parameters were not different between groups, except that infants in Group D/E had lower birthweight (BW) (1655 ± 1091 vs. 1858 ± 1027 g, p = 0.006), a higher initial FiO2 setting (83% vs. 72%, p < 0.001), and a higher rate of nitric oxide exposure (21.8% vs. 11.1%, p = 0.004) in comparison to infants who survived (Group S). The initial cut-offs for a successful response on ABG were defined as pH >7.065 (OR: 19.74, 95% CI 4.83-80.6, p < 0.001), HCO3 >16.35 mmol/L (OR: 1.06, 95% CI 1.01-1.1, p = 0.006), and lactate level <3.75 mmol/L (OR: 1.09%95 CI 1.01-1.16, p = 0.006). Rescue HFOV duration was associated with retinopathy of prematurity (p = 0.005) and moderate or severe chronic lung disease (p < 0.001), but not with patent ductus arteriosus or intraventricular hemorrhage, in survivors (p > 0.05). CONCLUSION: Rescue HFOV as defined for this population was successful in more than half of the patients with CV failure. Although the response was not associated with gestational age, underlying disease, device used, or initial MV settings, it seemed to be more effective in patients with higher BW and those not requiring nitric oxide. Initial pH, HCO3, and lactate levels on ABG may be used as predictors of a response to rescue HFOV.

Non-Invasive Ventilation in Neonatology.

BACKGROUND: Invasive mechanical ventilation (IMV) has been replaced by early continuous positive airway pressure (CPAP) in the treatment of respiratory distress syndrome (RDS) in preterm infants aiming to reduce the rate of bronchopulmonary dysplasia (BPD). Subsequently, modern non-invasive ventilation strategies (NIV) were introduced into clinical practice with limited evidence of effects on pulmonary and neurodevelopmental outcomes. METHODS: We performed a selective literature search in PubMed including randomized controlled trials (RCT) (n ≥ 200) and meta-analyses published in the field of NIV in neonatology and follow-up studies focusing on long term pulmonary and neurodevelopmental outcomes. RESULTS: Individual studies do not show a significant risk reduction for the combined endpoint death or BPD in preterm infants caused by early CPAP in RDS when compared to primary intubation. One meta-analysis comparing four studies found CPAP significantly reduces the risk of BPD or death (relative risk: 0.91; 95% confidence interval [0.84;0.99]). Nasal intermittent positive pressure ventilation (NIPPV) as a primary ventilation strategy reduces the rate of intubations in infants with RDS (RR: 0.78 [0.64;0.94]) when compared to CPAP but does not affect the rate of BPD (RR: 0.78 [0.58;1.06]). CONCLUSION: Early CPAP reduces the need for IMV and the risk of BPD or death in preterm infants with RDS. NIPPV may offer advantages over CPAP regarding intubation rates. Networking-based follow-up programs are required to assess the effect of NIV on long term pulmonary and neurodevelopmental outcomes.

Comparison of Early Nasal Intermittent Positive Pressure Ventilation and Nasal Continuous Positive Airway Pressure in Preterm Infants with Respiratory Distress Syndrome.

AIMS: To compare the effect of early nasal intermittent positive pressure ventilation (nIPPV) and nasal continuous positive airway pressure (nCPAP) in terms of the need for endotracheal ventilation in the treatment of respiratory distress syndrome (RDS) in preterm infants born between 24 and 32 gestational weeks. METHODS: This is a randomized, controlled, prospective, single-centered study. Forty-two infants were randomized to nIPPV and 42 comparable infants to nCPAP (birth weight 1356 ± 295 and 1359 ± 246 g and gestational age 29.2 ± 1.7 and 29.4 ± 1.5 weeks, respectively). RESULTS: The need for endotracheal intubation and invasive mechanical ventilation was significantly lower in the nIPPV group than the nCPAP group (11.9% and 40.5%, respectively, p < 0.05). There were no differences in the duration of total nasal respiratory support, duration of invasive mechanical ventilation, bronchopulmonary dysplasia or other early morbidities. CONCLUSION: nIPPV compared with nCPAP reduced the need for endotracheal intubation and invasive mechanical ventilation in premature infants with RDS.

Ultra-low tidal volume ventilation-A novel and effective ventilation strategy during experimental cardiopulmonary resuscitation.

BACKGROUND: The effects of different ventilation strategies during CPR on patient outcomes and lung physiology are still poorly understood. This study compares positive pressure ventilation (IPPV) to passive oxygenation (CPAP) and a novel ultra-low tidal volume ventilation (ULTVV) regimen in an experimental ventricular fibrillation animal model. STUDY DESIGN: Prospective randomized controlled trial. ANIMALS: 30 male German landrace pigs (16-20 weeks). METHODS: Ventricular fibrillation was induced in anesthetized and instrumented pigs and the animals were randomized into three groups. Mechanical CPR was initiated and ventilation was either provided by means of standard IPPV (RR: 10/min, Vt: 8-9 ml/kg, FiO2: 1,0, PEEP: 5 mbar), CPAP (O2-Flow: 10 l/min, PEEP: 5 mbar) or ULTVV (RR: 50/min, Vt: 2-3 ml/kg, FiO2: 1,0, PEEP: 5 mbar). Guideline-based advanced life support was applied for a maximum of 4 cycles and animals achieving ROSC were monitored for 6 h before terminating the experiment. Ventilation/perfusion ratios were performed via multiple inert gas elimination, blood gas analyses were taken hourly and extended cardiovascular measurements were collected constantly. Brain and lung tissue samples were taken and analysed for proinflammatory cytokine expression. RESULTS: ULTVV provided sufficient oxygenation and ventilation during CPR while demanding significantly lower respiratory and intrathoracic pressures. V/Q mismatch was significantly decreased and lung injury was mitigated in surviving animals compared to IPPV and CPAP. Additionally, cerebral cytokine expression was dramatically reduced. CONCLUSION: Ultra-low-volume ventilation during CPR in a porcine model is feasible and may provide lung-protective benefits as well as neurological outcome improvement due to lower inflammation. Our results warrant further studies and might eventually lead to new therapeutic options in the resuscitation setting.

[Comparison of clinical efficacy of two noninvasive respiratory support therapies for respiratory distress syndrome in very low birth weight preterm infants].

OBJECTIVE: To compare the clinical efficacy of nasal intermittent positive pressure ventilation (NIPPV) and heated humidified high flow nasal cannula (HHHFNC) in the treatment of respiratory distress syndrome (RDS) among very low birth weight (VLBW) preterm infants. METHODS: A total of 89 very low birth weight premature infants with respiratory distress syndrome (RDS) who were randomly administered with NIPPV (n=46) and HHHFNC (n=43) as an initial respiratory support. The incidence of initial treatment failure, the usage of pulmonary surfactant (PS), the parameters of respiratory support treatment and the incidence of complications were compared between the two groups. RESULTS: There were no significant differences between the NIPPV and HHHFNC groups in the following items: the rate of intubation within 72 hours, rate of PS use, duration of invasive or non-invasive mechanical ventilation, duration of oxygen therapy, and incidence rates of severe apnea and pneumonia (P>0.05). There were also no significant differences in the incidence rates of bronchopulmonary dysplasia, necrotizing enterocolitis, retinopathy of prematurity, patent ductus arteriosus, intracranial hemorrhage, and air leak between the two group (P>0.05). The incidence rate of nose injury in the NIPPV group was higher than that in the HHHFNC group (P<0.05). CONCLUSIONS: As an initial respiratory support for very low birth weight preterm infants with RDS, HHHFNC has a similar clinical effect as NIPPV, suggesting that HHHFNC is a safe and effective clinical option as a non-invasive ventilation treatment.

Pneumatosis intestinalis in a preterm infant: should we treat all intestinal pneumatosis as necrotising enterocolitis?

Gastric pneumatosisis a very rare site of pneumatosis intestinalis (PI), and we report this finding in a preterm female infant with cyanotic congenital heart disease. The infant was stable initially on nasal intermittent mandatory ventilation; however, torrential pulmonary flow through a large patent ductus arteriosus prompted closure using oral ibuprofen. After an episode of haematochezia, she developed PI, affecting mainly the gastric wall and small intestine with portal venous gas. Her bowel movements were regular, with no abdominal distension or significant gastric aspirates. She was haemodynamically stable with negative infective markers. Management consisted of endotracheal intubation and ventilation, gastric decompression and broad-spectrum antibiotics. Both the gastric and intestinal pneumatosis resolved within 24 hours and she made an uneventful recovery. If PI is not due to necrotising enterocolitis, enteral nutrition can be initiated early and prolonged course of broad-spectrum antibiotics could have been avoided.