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.

Non-invasive neurally adjusted ventilatory assist (NIV-NAVA) reduces extubation failures in preterm neonates-A systematic review and meta-analysis.

AIM: To analyse the evidence of non-invasive neurally adjusted ventilatory assist (NIV-NAVA) in preterm neonates compared to nasal continuous positive airway pressure (nCPAP) or nasal intermittent positive pressure ventilation (NIPPV). METHODS: We performed a systematic review and meta-analysis of randomised controlled trials and included studies where NIV-NAVA was analysed in preterm (<37 gestational weeks) born neonates. Our main outcomes were the need for endotracheal intubation, the need for surfactant therapy, and reintubation rates. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated. RESULTS: A total of five studies were included. The endotracheal intubation rate was 25% in the NIV-NAVA group and 26% in the nCPAP group (RR 0.91, CI: 0.56-1.48). The respective rates for surfactant therapy were 30% and 35% (RR 0.85, CI: 0.56-1.29). The reintubation rate in neonates previously invasively ventilated was 8% in the NIV-NAVA group and 29% in the nCPAP/NIPPV group (RR 0.29, 95%CI: 0.10-0.81). Evidence certainty was rated as low for all outcomes. CONCLUSIONS: NIV-NAVA as the primary respiratory support did not reduce the need for endotracheal intubation or surfactant therapy. NIV-NAVA seemed to reduce the reintubation rate after extubation in pre-term neonates.

Continuous Positive Airway Pressure versus Nasal Intermittent Positive Pressure Ventilation in Preterm Neonates: What if Mean Airway Pressures Were Equivalent?

Respiratory support for preterm neonates in modern neonatal intensive care units is predominantly with the use of noninvasive interfaces. Continuous positive airway pressure (CPAP) and nasal intermittent positive pressure ventilation (NIPPV) are the prototypical and most commonly utilized forms of noninvasive respiratory support, and each has unique gas flow characteristics. In meta-analyses of clinical trials till date, NIPPV has been shown to likely reduce respiratory failure and need for intubation compared to CPAP. However, a significant limitation of the included studies has been the higher mean airway pressures used during NIPPV. Thus, it is unclear to what extent any benefits seen with NIPPV are due to the cyclic pressure application versus the higher mean airway pressures. In this review, we elaborate on these limitations and summarize the available evidence comparing NIPPV and CPAP at equivalent mean airway pressures. Finally, we call for further studies comparing noninvasive respiratory support modes at equal mean airway pressures. KEY POINTS: · Most current literature on CPAP vs. NIPPV in preterm neonates is confounded by use of higher mean airway pressures during NIPPV.. · In this review, we summarize existing evidence on CPAP vs. NIPPV at equivalent mean airway pressures.. · We call for future research on noninvasive support modes to account for mean airway pressures..

Continuous Positive Airway Pressure Does Not Improve Nonalcoholic Fatty Liver Disease in Patients with Obstructive Sleep Apnea. A Randomized Clinical Trial.

Rationale: Obstructive sleep apnea (OSA) is associated with development of nonalcoholic fatty liver disease (NAFLD). The effects of continuous positive airway pressure (CPAP) on NAFLD in patients with concomitant OSA are unknown.Objectives: To investigate the effects of autoadjusting CPAP versus subtherapeutic CPAP treatment over 6 months on NAFLD activities.Methods: Patients with NAFLD and OSA, as defined by respiratory event index ≥5/h diagnosed by a validated level 3 Embletta device, were randomized into group A) autoadjusting CPAP (4-20 cm H2O) or group B) subtherapeutic CPAP (pressure fixed at 4 cm H2O). The primary endpoint was the difference in changes in intrahepatic triglyceride as measured by proton magnetic resonance spectroscopy after 6 months of therapy. Key secondary endpoints included changes in controlled attenuation parameter (CAP) and liver stiffness measurement measured with transient elastography, and serum cytokeratin-18 fragment.Measurements and Main Results: A total of 120 patients were randomized equally into two groups. There were significant correlations between CAP and respiratory event index (r = 0.203, P = 0.026), percentage of total recording time with SaO2 < 90% (r = 0.265, P = 0.003), and oxygen desaturation index (r = 0.214, P = 0.019). After 6 months of treatment, there were no significant differences of changes in primary and secondary endpoints between the two treatment groups. Regression analysis showed that weight change over 6 months correlated with changes in both intrahepatic triglyceride and CAP (P < 0.001).Conclusions: Despite significant correlations between hepatic steatosis and markers of severity of OSA, CPAP alone did not improve hepatic steatosis and fibrosis. However, the additional role of weight reduction through lifestyle modification deserves further investigation.

Feasibility of bubble non-invasive positive pressure ventilation, a first-in-human study.

PURPOSE: Infant respiratory distress is  a significant cause of mortality globally. Bubble continuous positive airway pressure (CPAP) is a simple and effective therapy, but sicker infants may require additional support such as non-invasive positive-pressure ventilation (NIPPV). We investigated the feasibility of a simple, low-cost, non-electric bubble NIPPV device. METHODS: In this cross-over feasibility study, seven newborns with moderate respiratory distress (Downes score ≥ 3), weight > 1500 g and gestational age > 32 weeks were randomized to  4 h of treatment with bubble CPAP (5-8 cm H2O) vs. bubble NIPPV (Phigh 8-10 cm H2O/Plow 5-8 cm H2O) followed by 4 h of the alternate treatment. Treatment order (CPAP vs. NIPPV) was randomized. Outcome measures included hourly vital signs, Downes score and O2 saturation. Adverse events including pneumothorax, nasal septal necrosis, necrotizing enterocolitis and death before discharge were also recorded. RESULTS: It took nurses 39 (7.3) s to assemble the bubble NIPPV device. Patients had similar vital signs and Downes scores on both treatments; median (IQR) values on bubble CPAP vs. bubble NIPPV were: heart rate 140 (134.5, 144), 140 (134.5, 144); respiratory rate 70 (56, 80), 65 (58, 82), Downes score 4 (3, 5.75), 4 (3, 5), O2 96 (94, 98), 97 (96, 98). All newborns survived to discharge and there were no adverse events. . CONCLUSIONS: A simple, low-cost, non-electric method of providing NIPPV for newborns with respiratory distress is feasible in limited resource settings. Randomized-controlled trials comparing bubble CPAP and bubble NIPPV are justified.

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.

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.

Randomized trial of mask or prongs for nasal intermittent mandatory ventilation in term infants with transient tachypnea of the newborn.

BACKGROUND: The aim of this study was to compare nasal masks (NM) with binasal prongs (NP) for applying nasal intermittent mandatory ventilation (NIMV) by assessing the duration of respiratory distress, rate of intubation, and nasal trauma in term infants with transient tachypnea of the newborn (TTN). METHODS: Infants with a gestational age ≥37 weeks and birthweight ≥2,000 g who had NIMV administered for TTN were enrolled. We randomly allocated 80 neonates to the NM (n = 40) or NP (n = 40) group. Duration of respiratory distress was the primary outcome of this study. RESULTS: There were no statistically significant differences between the groups for the duration of tachypnea and NIMV (P = 0.94 and P = 0.13, respectively). No significant differences were observed between the two groups in terms of duration of oxygen supplementation and length of hospitalization (P = 0.72 and P = 0.70, respectively). The incidence of any grade of trauma and moderate trauma (grade II) was significantly higher in the NP group than in the NM group (P = 0.004 and P = 0.04, respectively). The rate of NIMV failure and other complications, including pneumothorax, pneumonia and feeding intolerance, was not significantly different in the groups. CONCLUSIONS: In term infants with TTN, delivering NIMV using NP in comparison to using NM appears to be similar with regard to the duration of respiratory distress and preventing intubation. However, the use of NP involves a greater risk of trauma than that of NM.

Expired Tidal Volume Variation in Extremely Low Birth Weight and Very Low Birth Weight Infants on Volume-Targeted Ventilation.

In a prospective study we describe the delivery of small tidal volumes to extremely low birth weight (ELBW) and very low birth weight (VLBW) infants using a volume-targeted ventilation mode (VTV). Tidal volume delivery was consistent for both ELBW and VLBW infants independent of gestational age, birth weight, and the target volume.

Work of breathing during HHHFNC and synchronised NIPPV following extubation.

Our aim was to compare the work of breathing (WOB) during synchronised nasal intermittent positive pressure ventilation (SNIPPV) and heated humidified high flow nasal cannula (HHHFNC) when used as post-extubation support in preterm infants. A randomised crossover study was undertaken of nine infants with a median gestational age of 27 (range 24-31) weeks and post-natal age of 7 (range 2-50) days. Infants were randomised to either SNIPPV or HHHFNC immediately following extubation. They were studied for 2 h on one mode and then switched to the other modality and studied for a further 2-h period. The work of breathing, assessed by measuring the pressure time product of the diaphragm (PTPdi), and thoracoabdominal asynchrony (TAA) were determined at the end of each 2-h period. The infants' inspired oxygen requirement, oxygen saturation, heart rate and respiratory rate were also recorded. The median PTPdi was lower on SNIPPV than on HHHFNC (232 (range 130-352) versus 365 (range 136-449) cmH2O s/min, p = 0.0077), and there was less thoracoabdominal asynchrony (13.4 (range 8.5-41.6) versus 36.1 (range 4.3-50.4) degrees, p = 0.038).Conclusion: In prematurely born infants, SNIPPV compared to HHHFNC post-extubation reduced the work of breathing and thoracoabdominal asynchrony. What is Known: • The work of breathing and extubation failure are not significantly different in prematurely-born infants supported by HHHFNC or nCPAP. • SNIPPV reduces inspiratory effort and increases tidal volume and carbon dioxide exchange compared to nCPAP in prematurely born infants. What is New: • SNIPPV, as compared to HHHFNC, reduced the work of breathing in prematurely-born infants studied post-extubation. • SNIPPV, as compared to HHHFNC, reduced thoracoabdominal asynchrony in prematurely born infants studied post-extubation.

Comparison between auto-trilevel and bilevel positive airway pressure ventilation for treatment of patients with concurrent obesity hypoventilation syndrome and obstructive sleep apnea syndrome.

PURPOSE: Our study aims to compare the difference in clinical efficacy between auto-trilevel positive airway pressure (auto-trilevel PAP) ventilator and conventional fixed bilevel positive airway pressure (BiPAP) ventilator for obesity hypoventilation syndrome (OHS) patients with coexisting moderate or severe obstructive sleep apnea hypopnea syndrome (OSAHS). METHODS: Twenty-three OHS patients with moderate or severe OSAHS enrolled between January 2015 and September 2017 underwent ventilation by three different modes of positive airway pressure (PAP) for 8 h per night. A single variable mode was applied at the first night followed by two nights when no PAP therapy was carried out as a washout period between each mode. The inspiratory positive airway pressure (IPAP) decided by PaCO2 was consistently used for modes 1, 2, and 3. In mode 1, the expiratory positive airway pressure (EPAP) issued by BiPAP was decided by the minimal PAP levels for cessation of snoring. However, in mode 2, the EPAP was fixed at 3 cmH2O higher than this value. With the use of auto-trilevel PAP in mode 3, the EPAP was set to initially match that of mode 1 but the end of EPAP (EEPAP) was automatically regulated to be elevated according to upper airway patency condition. We also compared the following parameters including apnea hypopnea index (AHI), minimal SpO2 (miniSpO2), arousal index, and sleep efficiency during sleep; PaCO2 in the morning and Epword sleepiness score (ESS) at daytime were measured prior to and during PAP treatment as well as between three selected PAP modes. RESULTS: Compared with the parameters before ventilation therapies, all three variable modes of ventilation were associated with a higher nocturnal miniSpO2 and sleep efficiency (all P < 0.01). Among the three variable modes, mode 3 resulted in not only the lowest arousal index and daytime ESS but also the highest sleep efficiency. Compared to mode 1, mode 2 demonstrated a significantly reduced AHI and an elevated miniSpO2 and morning PaCO2 (all P < 0.05), while mode 3 was associated with a decreased AHI, an increased miniSpO2 (all P < 0.05), and no statistical change of PaCO2 following the end of PAP treatment (P > 0.05). Comparison between mode 2 and mode 3 revealed that mode 3 had a significantly lower PaCO2 (P < 0.05), but displayed no remarkable changes of AHI and miniSpO2 (all P > 0.05). CONCLUSION: Compared to fixed BiPAP ventilation, auto-trilevel PAP ventilation could more effectively correct hypercapnia, achieve lower index of nocturnal apnea and hypopnea, more improved sleep quality, and lower daytime sleepiness score. Auto-trilevel PAP ventilation is therefore more efficacious than conventional BiPAP ventilation in non-invasive ventilation therapy for OHS patients with concurrent moderate or severe OSAHS.

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.

New Ventilator Strategies: High-Frequency Oscillatory Ventilation Combined with Volume Guarantee.

High-frequency oscillatory ventilation (HFOV) has been proposed as an alternative method of invasive ventilation in immature infants to prevent ventilator lung injury. To better control the size of the high-frequency tidal volume and to prevent large tidal volumes, a new strategy of controlling the tidal volume during HFOV (VThf) has been developed, HFOV-volume guarantee (VG). Data from preclinical, neonatal animal studies in normal and surfactant-depleted lungs have demonstrated the feasibility of this technique to directly control the VThf in the normal compliance and low compliance situations. Different I:E ratios also can modify the effect of CO2 washout during HFOV combined with VG in a different way as without the VG modality. Finally, clinical use of this technique in newborn infants has demonstrated the possibility of using very high frequency combined with constant very low VThf to decrease the risk of lung trauma related to the ventilator.

Effect of pressure-controlled inverse ratio ventilation on dead space during robot-assisted laparoscopic radical prostatectomy: A randomised crossover study of three different ventilator modes.

BACKGROUND: Pressure-controlled inverse inspiratory to expiratory ratio ventilation (PC-IRV) is thought to be beneficial for reducing the dead space volume. OBJECTIVE: To investigate the effects of PC-IRV on the components of dead space during robot-assisted laparoscopic radical prostatectomy (RLRP). DESIGN: A randomised crossover study of three different ventilator modes. SETTING: A single university hospital from September 2014 to April 2015. PATIENTS: Twenty consecutive study participants undergoing RLRP. INTERVENTIONS: Patients were ventilated sequentially with three different modes in random order for 30 min: volume control ventilation (VCV; inspiratory to expiratory ratio 0.5), pressure control ventilation (PCV; inspiratory to expiratory ratio 0.5) and PC-IRV. Inverse inspiratory to expiratory ratio was adjusted individually by observing the expiratory flow-time wave to prevent the risk of dynamic pulmonary hyperinflation. MAIN OUTCOME MEASURES: The primary outcome included physiological dead space (VDphys), airway dead space (VDaw), alveolar dead space (VDalv) and shunt dead space (VDshunt). VDphys was calculated by Enghoff's method. We also analysed respiratory dead space (VDresp) and VDaw using a novel analytical method. Then, VDalv and VDshunt were calculated by VDalv = VDresp - VDaw and VDshunt = VDphys - VDresp, respectively. RESULTS: The VDphys/expired tidal volume (VTE) ratio in PC-IRV (29.2 ±â€Š4.7%) was significantly reduced compared with that in VCV (43 ±â€Š8.5%) and in PCV (35.9 ±â€Š3.9%). The VDshunt/VTE in PC-IRV was significantly smaller than that in VCV and PCV. VDaw/VTE in PC-IRV was also significantly smaller than that in VCV but not that in PCV. There was no significant change in VDalv/VTE. CONCLUSION: PC-IRV with the inspiratory to expiratory ratio individually adjusted by the expiratory flow-time wave decreased VDphys/VTE in patients undergoing RLRP. TRIAL REGISTRATION: University Hospital Medical Information Network in Japan 000014004.

[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.

Volume-targeted versus pressure-limited ventilation in neonates.

BACKGROUND: Damage caused by lung overdistension (volutrauma) has been implicated in the development of bronchopulmonary dysplasia (BPD). Modern neonatal ventilation modes can target a set tidal volume as an alternative to traditional pressure-limited ventilation (PLV) using a fixed inflation pressure. Volume-targeted ventilation (VTV) aims to produce a more stable tidal volume in order to reduce lung damage and stabilise the partial pressure of carbon dioxide (pCO2). OBJECTIVES: To determine whether VTV compared with PLV leads to reduced rates of death and death or BPD in newborn infants and to determine whether use of VTV affected outcomes including air leak, cranial ultrasound findings and neurodevelopment. SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 12), MEDLINE via PubMed (1966 to 13 January 2017), Embase (1980 to 13 January 2017) and CINAHL (1982 to 13 January 2017). We also searched clinical trials databases, conference proceedings and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. We contacted the principal investigators of studies to obtain supplementary information. SELECTION CRITERIA: Randomised and quasi-randomised trials comparing VTV versus PLV in infants of less than 44 weeks' postmenstrual age and reporting clinically relevant outcomes. DATA COLLECTION AND ANALYSIS: We assessed risk of bias for each trial using Cochrane methodology. We evaluated quality of evidence for each outcome using GRADE criteria. We tabulated mortality, rates of BPD, short-term clinical outcomes and long-term developmental outcomes. STATISTICS: for categorical outcomes, we calculated typical estimates for risk ratios (RR), risk differences (RD) and number needed to treat for an additional beneficial outcome (NNTB). For continuous variables, we calculated typical estimates for mean differences (MD). We used 95% confidence intervals (CI) and assumed a fixed-effect model for meta-analysis. MAIN RESULTS: Twenty randomised trials met our inclusion criteria; 16 parallel trials (977 infants) and four cross-over trials (88 infants). No studies were blinded and the quality of evidence for outcomes assessed varied from moderate to low.We found no difference in the primary outcome, death before hospital discharge, between VTV modes versus PLV modes (typical RR 0.75, 95% CI 0.53 to 1.07; low quality evidence). However, there was moderate quality evidence that the use of VTV modes resulted in a reduction in the primary outcome, death or BPD at 36 weeks' gestation (typical RR 0.73, 95% CI 0.59 to 0.89; typical NNTB 8, 95% CI 5 to 20) and the following secondary outcomes: rates of pneumothorax (typical RR 0.52, 95% CI 0.31 to 0.87; typical NNTB 20, 95% CI 11 to 100), mean days of mechanical ventilation (MD -1.35 days, 95% CI -1.83 to -0.86), rates of hypocarbia (typical RR 0.49, 95% CI 0.33 to 0.72; typical NNTB 3, 95% CI 2 to 5), rates of grade 3 or 4 intraventricular haemorrhage (typical RR 0.53, 95% CI 0.37 to 0.77; typical NNTB 11, 95% CI 7 to 25) and the combined outcome of periventricular leukomalacia with or without grade 3 or 4 intraventricular haemorrhage (typical RR 0.47, 95% CI 0.27 to 0.80; typical NNTB 11, 95% CI 7 to 33). VTV modes were not associated with any increased adverse outcomes. AUTHORS' CONCLUSIONS: Infants ventilated using VTV modes had reduced rates of death or BPD, pneumothoraces, hypocarbia, severe cranial ultrasound pathologies and duration of ventilation compared with infants ventilated using PLV modes. Further studies are needed to identify whether VTV modes improve neurodevelopmental outcomes and to compare and refine VTV strategies.

Effect of expiratory positive airway pressure on tidal volume during non-invasive ventilation.

During non-invasive ventilation (NIV), tidal volume ( Vt) will depend upon the difference between inspiratory and expiratory positive airway pressure (IPAP and EPAP, respectively), provided the respiratory muscles are relaxed and the lungs and chest wall therefore move along their passive pressure-volume curves. To test this hypothesis, we studied the effect of increasing EPAP during pressure-controlled modes of NIV in 30 long-term ventilator users (10 each with scoliosis, obesity hypoventilation or neuromuscular disorders). While maintaining the same IPAP, addition of 5 cmH2O of EPAP reduced mean Vt by 167 ml; 10 cmH2O reduced Vt by 367 ml. This pattern was seen in all three patient groups. EPAP has several potential advantages, for example maintaining upper airway patency, preventing basal atelectasis and facilitating triggering. EPAP does, however, appear to reduce Vt. Decreasing EPAP is an alternative to increasing IPAP if measurements of gas exchange during NIV indicate that ventilation is inadequate.

[Research advances in neonatal nasal intermittent positive pressure ventilation].

Nasal intermittent positive pressure ventilation (NIPPV) can augment nasal continuous positive airway pressure (nCPAP) by delivering intermittent positive pressure ventilation in a noninvasive way and can provide a new option for neonatal noninvasive respiratory support. NIPPV has an advantage over nCPAP in primary and post-extubation respiratory support. Moreover, it can reduce severe apnea of prematurity. Synchronized NIPPV has promising application prospects. This review article summarizes the advances in the application of NIPPV in neonatal respiratory support to promote the understanding and standardization of this technique.

Treatment of neonates with meconium aspiration syndrome by proportional assist ventilation and synchronized intermittent mandatory ventilation: a comparison study.

BACKGROUND: This study aimed to compare the relevant clinical parameters of neonates with MAS who are supported by proportion assisted ventilation (PAV) and synchronized intermittent mandatory ventilation (SIMV). METHODS: Forty neonates diagnosed as MAS who required mechanical ventilation were divided randomly into PAV group and SIMV group (N.=20). The respiratory rate (RR), heart rate (HR), peak inspiratory pressure (PIP), mean arterial blood pressure (MABP), arterial-to-alveolar oxygen tension ratio (a/APO2), fraction of inspiration oxygen (FiO2), mean airway pressure (MAP) and tidal volume (VT) were measured before the ventilation, 1,12, 24, 48 hours after the ventilation and before weaning. RESULTS: We observed no significant differences in the mechanical ventilation time, oxygen supply time, hospital stay between PAV and SIMV groups. In addition, we found no significant differences in HR, MABP, a/APO2 and FiO2 at every time point between two groups (P>0.05). However, we observed significant differences in RR, MAP, PIP and VT at every time point between two groups (P<0.05). CONCLUSIONS: PAV and SIMV might be a useful ventilator mode to support the neonates with MAS who require ventilation. To achieve the same effect, PAV adopts rapid shallow breathing pattern, with smaller tidal volume and lower MAP and PIP.

[THE IMPACT OF PERINATAL METABOLIC DISORDERS CHOICE MODE MECHANICAL VENTILATION IN NEWBORNS.]

THE AIM: To study the influence of perinatal metabolic disorders, metabolism on the choice of mode of artificial lung ventilation in newborns. MATERIALS AND METHODS: The study included 73 neonates with severe respiratory failure, therefore, all children underwent ALV Depending on the mode ofventilation, patients were divided into two groups: group 1 - 33 neonates who were at the beginning of treatment on a ventilator in the SIMV mode, then led to HFO ventilation; group 2 - 40 neonates who underwent only the SIMV The study used following research methods: analysis ofpregnancy anamnestic data; clinical assessment of the newborn's condition at birth including Apgar score (AS) on the 1st minute after birth; registration of changes of mode and parameters of mechanical ventilation: a mathematical calculation of oxygenation index (0I); determination of triglycerides and cholesterol in the central venous blood of newborns in thefirst hours ofpostnatal life and on the 5th day of life Results: At birth the triglycerides level in the blood of newborns is reduced and didn't differ signicantly between the groups. Along with this,. the newborns of 1st group remained impaired oxygen status, severe hypoxia, progressive increase of 01 not resolved in the conventional ventilation, which is an indication to lead the children to HFO ventilation. CONCLUSION: Asphyxia at birth, resistant to therapy, characterized by worsening hypoxemia, impaired lung function oxygenation, the increase of lactate in the blood, deep base deficiency, disorders of the metabolism of triglycerides and cholesterol and high oxygenation index are testimony to the high-frequency oscillatory ventilation. Pathogenetically justified the use of this kind of respiratory theory, not only during RDSN.