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.

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.

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 .

Fluctuations in Oxygen Saturation during Synchronized Nasal Intermittent Positive Pressure Ventilation and Nasal High-Frequency Oscillatory Ventilation in Very Low Birth Weight Infants: A Randomized Crossover Trial

BACKGROUND

Very low birth weight (VLBW) infants on noninvasive ventilation (NIV) experience frequent fluctuations in oxygen saturation (SpO2) that are associated with an increased risk for mortality and severe morbidities.

METHODS

In this randomized crossover trial, VLBW infants (n = 22) born 22+3 to 28+0 weeks on NIV with supplemental oxygen were allocated on two consecutive days in random order to synchronized nasal intermittent positive pressure ventilation (sNIPPV) and nasal high-frequency oscillatory ventilation (nHFOV) for 8 h. nHFOV and sNIPPV were set to equivalent mean airway pressure and transcutaneous pCO2. Primary outcome was the time spent within the SpO2 target (88-95%).

RESULTS

During sNIPPV, VLBW infants spent significantly more time within the SpO2 target (59.9%) than during nHFOV (54.6%). The proportion of time spent in hypoxemia (22.3% vs. 27.1%) and the mean fraction of supplemental oxygen (FiO2) (29.4% vs. 32.8%) were significantly reduced during sNIPPV, while the respiratory rate (50.1 vs. 42.6) was significantly higher. Mean SpO2, SpO2 above the target, number of prolonged (>1 min) and severe (SpO2 <80%) hypoxemic episodes, parameters of cerebral tissue oxygenation using NIRS, number of FiO2 adjustments, heart rate, number of bradycardias, abdominal distension and transcutaneous pCO2 did not differ between both interventions.

CONCLUSIONS

In VLBW infants with frequent fluctuations in SpO2, sNIPPV is more efficient than nHFOV to retain the SpO2 target and to reduce FiO2 exposure. These results demand more detailed investigations into cumulative oxygen toxicities during different modes of NIV over the weaning period, particularly with regard to consequences for long-term outcomes.

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.

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.

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.

[Safety evaluation on different ventilation strategies set for neonatal respiratory distress syndrome: a network Meta-analysis]

Objective: To evaluate the relative safety of different ventilation methods regarding mortality and rates of complication, on neonatal respiratory distress syndrome (NRDS). Methods: Network Meta-analysis was used to collect data on randomized controlled trials of pulmonary ventilation strategies in preterm infants with a mean gestational age of less than 32 weeks. Diagnostic criteria on NRDS were published in the PubMed, Cochrane, Web of Science, EBSCO, and Springer Link databases from January 1986 to June 2018. Revman 5.3 software was used to evaluate the quality of studies, based on the Cochrane quality assessment tool. Data were analyzed by Bayesian and frequency methods, using both Win BUGS 1.4.3 and STATA 13.0 software. Safety of different ventilation strategies for NRDS mortality and complications would include intraventricular hemorrhage (IVH), patent ductus arteriosus (PDA) and retinopathy of prematurity (ROP) and were evaluated. Counted data was displayed by OR and 95%CI. Results: A total of 31 RCTs were included in this paper, including 5 827 preterm infants and 11 ventilation strategies. There were no statistically significant differences appearing in 11 ventilation strategies on mortality, PDA or ROP. IVH results were reported in 28 studies. Compared with nasal intermittent positive pressure ventilation (NIPPV), both high- frequency oscillation ventilation (HFOV) (OR=3.33, 95%CI: 1.08-16.67, P<0.05) and synchronized intermittent mechanical ventilation (SIMV) (OR=8.22, 95%CI: 1.25-29.44, P<0.05) schemes seemed to have increased the risk of IVH in preterm infants with NRDS. NIPPV appeared the optimal ventilation strategy in the rankings of cumulative probability. Results on clustering showed that NIPPV was probably the best ventilation strategy for children with NRDS after considering the orders of IVH, PDA and ROP on mortality, respectively. However, HFOV, IMV, and SIMV did not seem to be the ideal ventilated strategies. Conclusions: Most of the clinical decision makers might prefer using NIPPV in the treatment of children with NRDS through mechanical ventilation systems to reduce both the incidence and death caused by IVH, PDA and ROP. It was not recommended to use HFOV, SIMV and IMV in treating NRDS with gestational less than 32 weeks. We suggested that larger numbers of multi-center RCTs ba carried out to make the above conclusions more convincing.

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.

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.

Positive Pressure versus Pressure Support Ventilation at Different Levels of PEEP Using the ProSeal™ Laryngeal Mask Airway

We compared positive pressure ventilation with pressure support ventilation at different levels of positive end expiratory pressure (PEEP) using the ProSeal laryngeal mask airway (PLMA). Forty-two anaesthetized adults (ASA 1-2, aged 19 to 63 years) underwent positive pressure ventilation and then pressure support ventilation each with PEEP set at 0, 5 and 10 cmH2O in random order. Pressure support ventilation was with the inspired tidal volume (VTInsp) set at 7 ml/kg and the respiratory rate adjusted to maintain the end-tidal CO2 (ETCO2) at 40 mmHg. Pressure support ventilation was with pressure support set at 5 cmH2O above PEEP and initiated when inspiration produced a 2 cmH2O reduction in airway pressure. Tidal volumes were similar during positive pressure and pressure support ventilation with PEEP, but were higher for the former without PEEP. Respiratory rate and peak inspiratory flow rate were higher during pressure support than positive pressure ventilation (all P<0.001). Peak airway pressure (Ppaw), mean airway pressure (Mpaw), peak expiratory flow rate, and expired airway resistance were lower during pressure support than positive pressure ventilation (all P<0.001). With PEEP set at 10 cmH2O, ETCO2 was lower for pressure support than positive pressure ventilation. During positive pressure ventilation, there was an increase in Ppaw, Mpaw and dynamic compliance (Cdyn) with increasing levels of PEEP (all P<0.01). During pressure support ventilation, there was an increase in inspired and expired tidal volume, Ppaw, peak inspiratory and expiratory flow rates and Cdyn, and a reduction in ETCO2, work of breathing, and expired airway resistance with increasing levels of PEEP (all P<0.01). There were no differences in SpO2, non-invasive mean arterial pressure, heart rate or leak fraction. We conclude that pressure support ventilation provides equally effective gas exchange as positive pressure ventilation during PLMA anaesthesia with or without PEEP at the tested settings. During pressure support, PEEP increases ventilation and reduces work on breathing without increasing leak fraction.

Comparison of bilevel positive airway pressure and average volume-assured pressure support mode in terms of patient compliance and treatment success in hypercapnic patients. A cross-sectional study

AIM

It is necessary for an effective NIV application to provide proper modality selection, sufficient minute ventilation (MV), also the amount of leakage on the circuit must be minimized and patient-ventilator adaptation must be achieved.

METHODS

30 patients with acute respiratory failure as a result of either internal or postoperative reasons were included in the study. Patient comfort was analyzed with a scale ranging from 0 to 2. Firstly the patient was used for two hours in BIPAP modality, after then the AVAPS modality (Period Av) was applied by setting the required rates the same mask. During BIPAP and AVAPS, arterial blood gases analysis, comfort scale and hemodynamic parameters were recorded in the 30th minute, 1st hour and 2nd hour.

RESULTS

According to the assessment of arterial blood gases, the pH changes of both periods were statistically significant compared to their baseline values (p=0.001). Treatment compliance of the patients was significantly better at AVAPS modality at all times (p = 0.015, p = 0.008, p = 0.008, respectively).

CONCLUSIONS

According to the results obtained from this study, the AVAPS modality has positive effects on pH and gas variation and patient comfort; therefore, it can be confidently used in clinical practice.

KEY WORDS

Average Volume Assured Pressure Support, Bilevel Continuous Positive Airway Pressure, Intensive Care Units, Noninvasive Ventilation, Patients Compliance.

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.

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.

Effective ventilation: The most critical intervention for successful delivery room resuscitation

Lung aeration is the critical first step that triggers the transition from fetal to postnatal cardiopulmonary physiology after birth. When an infant is apneic or does not breathe sufficiently, intervention is needed to support this transition. Effective ventilation is therefore the cornerstone of neonatal resuscitation. In this article, we review the physiology of cardiopulmonary transition at birth, with particular attention to factors the caregiver should consider when providing ventilation. We then summarize the available clinical evidence for strategies to monitor and perform positive pressure ventilation in the delivery room setting.

Predictors of death including quality of positive pressure ventilation during newborn resuscitation and the relationship to outcome at seven days in a rural Tanzanian hospital

Background

Effective positive pressure ventilation (PPV) of non-breathing newborns is crucial in facilitating cardio-respiratory adaptation at birth. Identifying predictors of death in newborns receiving PPV is important in order to facilitate preventative strategies.

Objective

The objective of this study was to determine the perinatal predictors of death including the quality of PPV administered among admitted newborns.

Methods

An observational study of admitted newborns who received PPV after birth was conducted. Research assistants observed all deliveries and recorded perinatal events on data collection forms. Measured heart rate (HR) and ventilation parameters were then compared between newborns who died and survivors.

Results

Newborns (n = 232) were studied between October 2014 and November 2016. Newborns who died (n = 53) compared to survivors (n = 179) had more fetal heart rate (FHRT) abnormalities (12/53 vs 19/179; p = 0.03); lower initial HR (<100 beats/minute) at start of PPV (44/48 vs 77/139; p<0.001); and a longer time for HR to increase >100 beats/minute from birth (180 vs 149 seconds; p = 0.07). Newborns who died compared to survivors took longer time (14 vs 4 seconds; p = 0.008) and more inflations (7 vs 3; p = 0.006) to achieve an expired volume (V_t) of 6 ml/kg, respectively. Median delivered V_t during the first 60 seconds of PPV was less in newborns who died compared to survivors (5 vs 6 ml/kg; p = 0.12). Newborns who died proceeded to severe encephalopathy (15/31 vs 1/59; p<0.001) compared to survivors.

Conclusion

Depressed newborns who proceeded to death compared to survivors, exhibited delayed HR response to PPV which may partly reflect FHRT abnormalities related to interruption of placental blood flow, and/or a timely delay in establishing adequate V_t. Depressed newborns progressed to moderate/severe encephalopathy. Improving FHRT monitoring to identify fetuses at risk for expedited delivery, coupled with optimizing delivery room PPV might decrease mortality in this 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.

[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.

[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.

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.

Relationships between long-term observations of motor milestones and genotype analysis results in childhood-onset Japanese spinal muscular atrophy patients

AIM

To clarify the long-term natural history of SMA in Japanese patients by investigating the peak motor milestones of cases 7months through 57years of age, in efforts to contribute to evaluating outcomes of new therapeutic interventions.

METHODS

We sub-classified 112 SMA type I-III cases into type Ia, type Ib, type IIa, type IIb, type IIIa and type IIIb, according to peak motor milestone achieved, and analyzed the SMN1, SMN2 and NAIP genes in relation to clinical subtypes.

RESULTS

In type I cases, there was a significant difference (p<0.0001), depending on whether or not head control was obtained, in the time of ventilation support being required. In type II cases as well, the time at which the ability to maintain the sitting position independently was lost also differed significantly (p<0.01) between those acquiring the ability to sit unaided within eight months after birth and those acquiring this ability after eight months of age. In type III cases, being able versus unable to climb stairs was associated with a significant difference (p=0.02) in the median time until loss of walking independently. Positive correlations were also seen between copy numbers and the clinical severity of SMA.

CONCLUSION

Our long-term results show peak motor milestone evaluations distinguishing between subtypes to be useful not only as outcome measures for assessing treatment efficacy in clinical trials but also for predicting the clinical courses of Japanese SMA patients.

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.

Neuromodulation of Limb Proprioceptive Afferents Decreases Apnea of Prematurity and Accompanying Intermittent Hypoxia and Bradycardia

BACKGROUND

Apnea of Prematurity (AOP) is common, affecting the majority of infants born at <34 weeks gestational age. Apnea and periodic breathing are accompanied by intermittent hypoxia (IH). Animal and human studies demonstrate that IH exposure contributes to multiple pathologies, including retinopathy of prematurity (ROP), injury to sympathetic ganglia regulating cardiovascular action, impaired pancreatic islet cell and bone development, cerebellar injury, and neurodevelopmental disabilities. Current standard of care for AOP/IH includes prone positioning, positive pressure ventilation, and methylxanthine therapy; these interventions are inadequate, and not optimal for early development.

OBJECTIVE

The objective is to support breathing in premature infants by using a simple, non-invasive vibratory device placed over limb proprioceptor fibers, an intervention using the principle that limb movements trigger reflexive facilitation of breathing.

METHODS

Premature infants (23-34 wks gestational age), with clinical evidence of AOP/IH episodes were enrolled 1 week after birth. Caffeine treatment was not a reason for exclusion. Small vibration devices were placed on one hand and one foot and activated in 6 hour ON/OFF sequences for a total of 24 hours. Heart rate, respiratory rate, oxygen saturation (SpO2), and breathing pauses were continuously collected.

RESULTS

Fewer respiratory pauses occurred during vibration periods, relative to baseline (p<0.005). Significantly fewer SpO2 declines occurred with vibration (p<0.05), relative to control periods. Significantly fewer bradycardic events occurred during vibration periods, relative to no vibration periods (p<0.05).

CONCLUSIONS

In premature neonates, limb proprioceptive stimulation, simulating limb movement, reduces breathing pauses and IH episodes, and lowers the number of bradycardic events that accompany aberrant breathing episodes. This low-cost neuromodulatory procedure has the potential to provide a non-invasive intervention to reduce apnea, bradycardia and intermittent hypoxia in premature neonates.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02641249.

The application of nasal synchronized intermittent mandatory ventilation in primary apnea of prematurity

We aimed to evaluate the efficacy of nasal synchronized intermittent mandatory ventilation (nSIMV) in preterm infants with primary apnea of prematurity (AOP). Forty-four preterm infants with AOP were divided into the nSIMV group or nasal continuous positive airway pressure (nCPAP) group. Clinical symptoms, signs and blood gas results following nSIMV or nCPAP were compared between the two groups. Infants receiving nSIMV had a greater reduction in apneic spells and a greater decrease in bradycardia than those receiving nCPAP. Compared with the nCPAP group, the nSIMV group had a lower incidence of respiratory support failure (9.1% vs. 27.3%; p<0.05), a lower incidence of hypercarbia (4.5% vs. 18.2%; p<0.05) and a lower incidence of gastrointestinal complications (4.5% vs. 13.6%; p<0.05). This study showed that nSIMV was more effective in respiratory support in preterm infants with AOP.

Bench test evaluation of adaptive servoventilation devices for sleep apnea treatment

RATIONALE

Adaptive servoventilation devices are marketed to overcome sleep disordered breathing with apneas and hypopneas of both central and obstructive mechanisms often experienced by patients with chronic heart failure. The clinical efficacy of these devices is still questioned.

STUDY OBJECTIVES

This study challenged the detection and treatment capabilities of the three commercially available adaptive servoventilation devices in response to sleep disordered breathing events reproduced on an innovative bench test.

METHODS

The bench test consisted of a computer-controlled piston and a Starling resistor. The three devices were subjected to a flow sequence composed of central and obstructive apneas and hypopneas including Cheyne-Stokes respiration derived from a patient. The responses of the devices were separately evaluated with the maximum and the clinical settings (titrated expiratory positive airway pressure), and the detected events were compared to the bench-scored values.

RESULTS

The three devices responded similarly to central events, by increasing pressure support to raise airflow. All central apneas were eliminated, whereas hypopneas remained. The three devices responded differently to the obstructive events with the maximum settings. These obstructive events could be normalized with clinical settings. The residual events of all the devices were scored lower than bench test values with the maximum settings, but were in agreement with the clinical settings. However, their mechanisms were misclassified.

CONCLUSION

The tested devices reacted as expected to the disordered breathing events, but not sufficiently to normalize the breathing flow. The device-scored results should be used with caution to judge efficacy, as their validity depends upon the initial settings.

Feasibility study on full closed-loop control ventilation (IntelliVent-ASV™) in ICU patients with acute respiratory failure: a prospective observational comparative study

INTRODUCTION

IntelliVent-ASV™ is a full closed-loop ventilation mode that automatically adjusts ventilation and oxygenation parameters in both passive and active patients. This feasibility study compared oxygenation and ventilation settings automatically selected by IntelliVent-ASV™ among three predefined lung conditions (normal lung, acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary disease (COPD)) in active and passive patients. The feasibility of IntelliVent-ASV™ use was assessed based on the number of safety events, the need to switch to conventional mode for any medical reason, and sensor failure.

METHOD

This prospective observational comparative study included 100 consecutive patients who were invasively ventilated for less than 24 hours at the time of inclusion with an expected duration of ventilation of more than 12 hours. Patients were ventilated using IntelliVent-ASV™ from inclusion to extubation. Settings, automatically selected by the ventilator, delivered ventilation, respiratory mechanics, and gas exchanges were recorded once a day.

RESULTS

Regarding feasibility, all patients were ventilated using IntelliVent-ASV™ (392 days in total). No safety issues occurred and there was never a need to switch to an alternative ventilation mode. The fully automated ventilation was used for 95% of the total ventilation time. IntelliVent-ASV™ selected different settings according to lung condition in passive and active patients. In passive patients, tidal volume (VT), predicted body weight (PBW) was significantly different between normal lung (n = 45), ARDS (n = 16) and COPD patients (n = 19) (8.1 (7.3 to 8.9) mL/kg; 7.5 (6.9 to 7.9) mL/kg; 9.9 (8.3 to 11.1) mL/kg, respectively; P 0.05). In passive ARDS patients, FiO2 and positive end-expiratory pressure (PEEP) were statistically higher than passive normal lung (35 (33 to 47)% versus 30 (30 to 31)% and 11 (8 to 13) cmH2O versus 5 (5 to 6) cmH2O, respectively; P< 0.05).

CONCLUSIONS

IntelliVent-ASV™ was safely used in unselected ventilated ICU patients with different lung conditions. Automatically selected oxygenation and ventilation settings were different according to the lung condition, especially in passive patients.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01489085.

[Comparative study on application of Duo positive airway pressure and continuous positive airway pressure in preterm neonates with respiratory distress syndrome]

OBJECTIVE

To determine whether early application of Duo positive airway pressure (DuoPAP), in comparison with nasal continuous positive airway pressure (NCPAP), can reduce the need for endotracheal intubation and mechanical ventilation and decrease the incidence of bronchopulmonary dysplasia (BPD) in preterm neonates with respiratory distress syndrome (RDS).

METHODS

In a single-center, randomized controlled trial, preterm neonates (gestational ages 30-35 weeks) with RDS were randomly assigned to receive DuoPAP (n=34) or NCPAP (n=33) within 6 hours of birth. If the two noninvasive ventilations were not effective, endotracheal intubation and mechanical ventilation were used, and pulmonary surfactant was administered as rescue therapy. The total invasive respiratory support rate and incidence of BPD within 24, 48 and 72 hours of birth were observed. The two groups were compared in terms of PaCO2, PaO2 and oxygenation index (OI) at 1, 12, 24, 48 and 72 hours after using the noninvasive respiratory support.

RESULTS

The total invasive respiratory support rates within 48 and 72 hours after birth were significantly lower in the DuoPAP group than in the NCPAP group (P<0.05). There was no difference in the incidence of BPD between the two groups (P>0.05). The OI in the DuoPAP group was significantly higher than in the NCPAP group at 1, 12, 24, 48 and 72 hours after noninlasive respiratory support (P<0.05). The DuoPAP group showed significantly lower PaCO2 than the NCPAP group at 1, 12, and 24 hours after noninvasive respiratory support (P<0.05). PaO2 was significantly higher in the DuoPAP group than in the NCPAP group at 1 and 12 hours after noninvasive respiratory support (P<0.05).

CONCLUSIONS

Compared with NCPAP, early application of DuoPAP can decrease the need for endotracheal intubation and mechanical ventilation in preterm neonates with RDS, showing promise for broad use.

Noninvasive respiratory support in the preterm infant

Multiple randomized controlled trials have suggested that nasal intermittent positive pressure ventilation, compared with nasal continuous airway pressure, prevents extubation failure and may decrease bronchopulmonary dysplasia. This article summarizes these studies and suggests strategies for the use of nasal intermittent positive pressure ventilation in neonates.

[Non-invasive positive pressure ventilation in stable COPD: has it any role?]

The role of non invasive positive pressure ventilation in stable COPD remains, in many ways, a controversial subject in pulmonology. In this article we are analysing the pro and con arguments and select the current indications, pointing out the unelucidated aspects of this kind of therapy.

[Nasal synchronized intermittent positive pressure ventilation for the treatment of apnea in preterm infants]

OBJECTIVE

To compare the efficacy of nasal synchronized intermittent positive pressure ventilation (NSIPPV) and nasal continuous positive airway pressure ventilation (NCPAP) for the treatment of apnea in preterm infants.

METHODS

Eighty preterm infants with apnea from August 2010 to January 2011 were randomly administered with NSIPPV and NCPAP (n=40 each).The blood gas results before and 2 hrs after ventilation, time of using ventilator, therapeutic efficacy and complications were compared between the two groups.

RESULTS

There were no significant differences in the blood gas results between the two groups before ventilation. The blood gas results (pH, PO2, PCO2) in the NSIPPV group were better than those in the NCPAP group 2 hrs after ventilation. The time of using ventilator in the NSIPPV group was shorter than that in the NCPAP group (50±9 h vs 91±11 h; P<0.01). There were no significant differences in the total effective rate between the NSIPPV and the NCPAP groups (95% vs 85%; P>0.05). The proportion of ventilator weaning within 3 days in the NSIPPV group (23/40) was higher than that in the NCPAP group (14/40) (P<0.05). The incidence of complications in the NSIPPV group was not different from that in the NCPAP group (22% vs 25%).

CONCLUSIONS

NSIPPV appears to be superior to NCPAP for the treatment of apnea in preterm infants.

[Lung volume recruitment in impending respiratory failure]

Lung volume recruitment can improve peak cough flows and respiratory compliance in patients who either do or do not require mechanical ventilation. There are several lung volume recruitment techniques: air stacking, glossopharyngeal breathing and mechanical insufflation-exsufflation with cough assist devices. The principle of lung volume recruitment is based on the insufflation of air in the lungs after maximal inspiration. In air stacking, a manual resuscitation bag is used for insufflation. Glossopharyngeal breathing requires the use of oropharyngeal and laryngeal muscles by the patient. The mechanical cough assist device exsufflates the air after insufflation. These techniques may prevent pulmonary complications, hospital admission and tracheotomy in patients with a reduced ability to cough, a proclivity towards atelectasis and recurrent airway infections. The combination of long-term mechanical ventilation with lung volume recruitment has led to further improvement in the prognosis of chronic respiratory failure. More patients may potentially benefit from lung volume recruitment than only those being converted from short-term to long-term mechanical ventilation.

[Parameters of controlled mechanical lung ventilation and external respiratory function during thoracoscopic surgeries in children of different age groups]

The purpose of the study is to estimate the parameters of mechanical ventilation and respiratory function during videotorachoscopic surgeries in children. 73 anesthesias were conducted in children aged 5 to 16 years of age. During the study, a detailed monitoring of respiratory function and parameters of mechanical ventilation was carried out. Indicators reflecting the lung function remained stable in all phases of the study. Parameters of mechanical ventilation during the study varied. Changes in PIP and MAP were similar in all age groups. The maximum changes of compliance were in the third group. One-lung ventilation is safe under certain conditions: increasing FiO2 from 0.5 to 1, the reduction of tidal volume up to 5-5.3 ml/kg, the use of a size or a half size smaller cuffed endotracheal tubes for intubation of the right and left main bronchus compared to those for tracheal intubation. For the intubation of the right main bronchus the endotracheal tube with the Murphy eye should be used, for the means ventilation of the upper lobe of the right lung. If the minute volume of breathing is adequate and there is no preoperative hypercapnia, the elimination of CO2 for one-lung ventilation is not disrupted and the tension of CO2 in arterial blood increases.

Volume-targeted versus pressure-limited ventilation in the neonate

BACKGROUND

Damage caused by lung overdistension (volutrauma) has been implicated in the development bronchopulmonary dysplasia (BPD). Modern neonatal ventilation modes can target a set tidal volume as an alternative to traditional pressure-limited ventilation using a fixed inflation pressure. Volume targeting aims to produce a more stable tidal volume in order to reduce lung damage and stabilise pCO(2)

OBJECTIVES

To determine whether volume-targeted ventilation (VTV) compared with pressure-limited ventilation (PLV) leads to reduced rates of death and BPD in newborn infants. Secondary objectives were to determine whether use of VTV affected outcomes including air leak, cranial ultrasound findings and neurodevelopment.

SEARCH STRATEGY

The search strategy comprised searches of the Cochrane Central Register of Controlled Trials, MEDLINE PubMed 1966 to January 2010, and hand searches of reference lists of relevant articles and conference proceedings.

SELECTION CRITERIA

All randomised and quasi-randomised trials comparing the use of volume-targeted versus pressure-limited ventilation in infants of less than 28 days corrected age.

DATA COLLECTION AND ANALYSIS

Two review authors assessed the methodological quality of eligible trials and extracted data independently. When appropriate, meta-analysis was conducted to provide a pooled estimate of effect. For categorical data the relative risk (RR) and risk difference (RD) were calculated with 95% confidence intervals. Number needed to treat was calculated when RD was statistically significant. Continuous data were analysed using weighted mean difference.

MAIN RESULTS

Twelve randomised trials met our inclusion criteria; nine parallel trials (629 infants) and three crossover trials (64 infants).The use of VTV modes resulted in a reduction in the combined outcome of death or bronchopulmonary dysplasia [typical RR 0.73 (95% CI 0.57 to 0.93), NNT8 (95% CI 5 to 33)]. VTV modes also resulted in reductions in pneumothorax [typical RR 0.46 (95% CI 0.25 to 0.84), NNT 17 (95% CI 10 to 100)], days of ventilation [MD -2.36 (95% CI -3.9 to -0.8)], hypocarbia [typical RR 0.56 (95%CI 0.33 to 0.96), NNT 4 (95% CI 2 to 25)] and the combined outcome of periventricular leukomalacia or grade 3-4 intraventricular haemorrhage [typical RR 0.48 (95% CI 0.28 to 0.84), NNT 11 (95% CI 7 to 50)].

AUTHORS' CONCLUSIONS

Infants ventilated using VTV modes had reduced death and chronic lung disease 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.

[Randomized trail of nasal synchronized intermittent mandatory ventilation compared with nasal continuous positive airway pressure in preterm infants with respiratory distress syndrome]

OBJECTIVE

To compare the efficacy of nasal synchronized intermittent mandatory ventilation (nSIMV) and nasal continuous positive airway pressure (nCPAP) in preterm infants with respiratory distress syndrome (RDS).

METHODS

Fifty preterm infants with RDS who received pulmonary surfactant were randomized to nSIMV and nCPAP groups after extubation. Clinical signs, symptoms and blood gas results following nSIMV or nCPAP were compared in the two groups.

RESULTS

Compared with the nCPAP group, the nSIMV group had a lower incidence of failure respiratory support (24% vs 60%; P<0.05), a lower incidence of hypercarbonia (12% vs 40%; P<0.05) and a lower incidence of hypoxia (24% vs 36%; P<0.05).

CONCLUSIONS

nSIMV is more effective in respiratory support in preterm infants with RDS.

Use of noninvasive ventilation in patients with amyotrophic lateral sclerosis

INTRODUCTION

Noninvasive positive pressure ventilation (NIPPV) is associated with improved survival in amyotrophic lateral sclerosis (ALS) and has been widely recommended. The extent of NIPPV use in ALS patients and the factors associated with its use have not been studied.

METHODS

A cross-sectional study using the ALS Patient Care Database. Analyses were performed to assess the association of patient and care characteristics with use of ventilatory support.

RESULTS

1458 patients were studied. 15.6% used NIPPV and 2.1% used invasive mechanical ventilation. Patients who used NIPPV were significantly more likely to be male and have higher income than those who did not. They were also more likely to have a gastrostomy tube, lower vital capacity, more severe disease, bulbar involvement and poorer general health status as measured by the SF-12 and Sickness Impact Profile. Multivariate analysis revealed that lower FVC, higher income and use of gastrostomy tube were independently associated with use of NIPPV.

CONCLUSIONS

NIPPV is used more than seven times as frequently as invasive ventilation in ALS patients. Patients who use NIPPV have more severe disease than those who do not use any respiratory intervention. Patients with lower income are less likely to use NIPPV, which raises concerns about disparities in the care of patients with ALS.

[Factors related to extubation failure in premature infants less than 32 weeks of gestation]

Even though ventilatory support for preterm infants has improved over the past few decades, about 30% of intubated preterm infants fail an extubation attempt. There are still no simple standards to determine the optimal extubation time for those infants.

OBJECTIVE

To identify factors related to extubation success or failure in preterm infants less than 32 weeks of gestation (WG).

POPULATION AND METHODS

Retrospective study including 162 newborns less than 32 WG, requiring mechanical ventilation within the first 24h of life. Successful extubation was defined as no need for reintubation for any reason at least 7 days after the first extubation attempt.

RESULTS

Forty-one infants failed extubation (25.3%); 149 infants (92%) had mechanical ventilation in their first 30min of life. These infants had a lower gestational age (p<0.001) and a lower birth weight (p=0.003). They required a higher FiO(2) (p<0.001) and maximum inspiratory pressure (p=0.002). The infants who failed extubation had a lower pH (p=0.001) and hematocrit (p=0.032), and a higher PCO(2) (p=0.003).

CONCLUSION

As previously described, a low gestational age is a major factor predicting the extubation failure. However, our data suggests that ventilator settings and blood gas should also be considered when attempting extubation, following written guidelines.

A randomized trial of non-synchronized Nasopharyngeal Intermittent Mandatory Ventilation (nsNIMV) vs. Nasal Continuous Positive Airway Pressure (NCPAP) in the prevention of extubation failure in pre-term < 1,500 grams

OBJECTIVE

To compare the rate of reintubation within 7 days after extubation and study the complications in premature infants who were randomized in the immediate postextubation period to either nsNIMV or NCPAP.

MATERIAL AND METHOD

This study was conducted in the neonatal unit of Queen Sirikit National Institute of Child Health between June 1 and November 30, 2006. Intubated premature infants born at GA < or = 34 weeks or with birth weight < or = 1500 gm, ready to be extubated before 4 weeks of age were recruited. Infants were randomized to either nsNIMV or NCPAP after extubation. Non-synchronized NIMV setting was the same as ventilator setting before extubation and NCPAP pressure was set at the same mean airway pressure of pre extubation ventilator value. Extubation was performed after intravenous loading dose of aminophylline. Primary outcome measurement was reintubation within 7 days of initial extubation and the secondary outcome was possible complications such as apnea, abdominal distension, gastrointestinal (GI) perforation, necrotizing enterocolitis (NEC), sepsis and death.

RESULTS

A total of 70 VLBW infants were admitted to the neonatal unit during the study period. A total of 57 infants were intubated of which 48 infants were recruited for the study; 24 were in the nsNIMV group and 24 were in the NCPAP group. Infants in the nsNIMV group had mean birth weight and body weight at the start of study less than that in the NCPAP group (984.8 +/- 218 vs. 1067 +/- 214 and 1185 +/- 219 vs. 1205 +/-191, p = 0.003, 0.02). The nsNIMV group also had a higher rate of RDS and antenatal steroid used when compared to the NCPAP group (19/24 vs. 12/24 and 17/24 vs. 8/24, p = 0.03, 0.01). The nsNIMV group had fewer males than in the NCPAP group (8/24 vs. 17/24, p = 0.01). Reintubation was similar in both groups but atelectasis and sepsis were statistically significant risk factor for reintubation in NCPAP group. There were no significant differences in treatment related complications between the two groups, with respect to incidence of apnea (41.7% in nsNIMV vs. 62.5% in NCPAP), abdominal distensions (8.3% in nsNIMVvs. 16.7% in NCPAP), NEC (4.2% in nsNIMVvs. 12.5 in NCPAP), sepsis (4.2% in nsNIMVvs. 8.3% NCPAP). No GI perforation was observed in both groups.

CONCLUSION

Non-invasive mode of ventilation, both NIMV and NCPAP, for weaning ofpre-term infants from ventilator may reduce the rate of reintubation in this group. Both modes seem to be equally safe. We believe that the use of non-invasive ventilator techniques will significantly reduce neonatal morbidity in the future. Additional prospective evaluation of these approaches should be conducted in the future.

Noninvasive ventilation in acute cardiogenic pulmonary edema

BACKGROUND

Noninvasive ventilation (continuous positive airway pressure [CPAP] or noninvasive intermittent positive-pressure ventilation [NIPPV]) appears to be of benefit in the immediate treatment of patients with acute cardiogenic pulmonary edema and may reduce mortality. We conducted a study to determine whether noninvasive ventilation reduces mortality and whether there are important differences in outcome associated with the method of treatment (CPAP or NIPPV).

METHODS

In a multicenter, open, prospective, randomized, controlled trial, patients were assigned to standard oxygen therapy, CPAP (5 to 15 cm of water), or NIPPV (inspiratory pressure, 8 to 20 cm of water; expiratory pressure, 4 to 10 cm of water). The primary end point for the comparison between noninvasive ventilation and standard oxygen therapy was death within 7 days after the initiation of treatment, and the primary end point for the comparison between NIPPV and CPAP was death or intubation within 7 days.

RESULTS

A total of 1069 patients (mean [+/-SD] age, 77.7+/-9.7 years; female sex, 56.9%) were assigned to standard oxygen therapy (367 patients), CPAP (346 patients), or NIPPV (356 patients). There was no significant difference in 7-day mortality between patients receiving standard oxygen therapy (9.8%) and those undergoing noninvasive ventilation (9.5%, P=0.87). There was no significant difference in the combined end point of death or intubation within 7 days between the two groups of patients undergoing noninvasive ventilation (11.7% for CPAP and 11.1% for NIPPV, P=0.81). As compared with standard oxygen therapy, noninvasive ventilation was associated with greater mean improvements at 1 hour after the beginning of treatment in patient-reported dyspnea (treatment difference, 0.7 on a visual-analogue scale ranging from 1 to 10; 95% confidence interval [CI], 0.2 to 1.3; P=0.008), heart rate (treatment difference, 4 beats per minute; 95% CI, 1 to 6; P=0.004), acidosis (treatment difference, pH 0.03; 95% CI, 0.02 to 0.04; P<0.001), and hypercapnia (treatment difference, 0.7 kPa [5.2 mm Hg]; 95% CI, 0.4 to 0.9; P<0.001). There were no treatment-related adverse events.

CONCLUSIONS

In patients with acute cardiogenic pulmonary edema, noninvasive ventilation induces a more rapid improvement in respiratory distress and metabolic disturbance than does standard oxygen therapy but has no effect on short-term mortality. (Current Controlled Trials number, ISRCTN07448447.)

[Changes of plasma B-type natriuretic peptide level during non-invasive ventilation in treating acute left heart failure]

OBJECTIVE

To assess the changes of B-type natriuretic peptide (BNP) levels during noninvasive ventilation in treating acute left heart failure.

METHODS

Totally 28 patients with acute left heart failure were randomly assigned to group A (n = 13; without non-invasive ventilation) and group B (n = 15; undergoing non-invasive ventilation). Another 10 healthy adults were enrolled as the normal control group. Plasma BNP were obtained with ELISA before treatment and 3 and 7 hours after treatment.

RESULTS

The plasma BNP levels were significantly higher in group A and group B than in the normal control group before treatment (P< 0.01). Three and 7 hours after treatment, the plasma BNP levels was significantly higher in group A than in the normal control group (P<0.05), while it was significantly lower in group B than in group A (P<0.05, P<0.01).

CONCLUSION

The plasma BNP level remarkably decreases in patients undergo non-invasive ventilation, suggesting that the plasma BNP level decreases along with the improvement of cardiac function.

Mechanical ventilatory support in preterm infants

A large proportion of premature infants presents with acute respiratory failure after birth and require mechanical ventilatory support. In addition to conventional mechanical ventilation, an increasing number of these infants are currently supported by newer modes including synchronized, volume targeted and noninvasive mechanical ventilation. While these new modes have improved weaning from mechanical ventilation they have not had a consistent impact on respiratory outcome or other morbidities. This is a review of the different modes of invasive and noninvasive mechanical ventilation used to support premature infants with respiratory failure.

[Choice of optimal respiratory therapy in patients operated for tumors of the posterior cranial fossa]

The results of two different approaches to respiratory support after surgical intervention into the structures of the posterior cranial fossa (PCF) are analyzed in 74 neurosurgical patients, including 41 patients having synchronized pressure support ventilation and 50-80% spontaneous intermittent mandatory ventilation (SIMV + PSV) (Group 1) and 33 patients receiving continuous positive end-expiratory airway pressure (CPAP + PSV) (Group 2). Respiratory therapy has been ascertained to provide at least 50-80% of the minute ventilation volume in neurosurgical patients after interventions into PCF when respiratory failure develops in the postoperative period. Diminished respiratory support may be performed only after neurological stabilization and within 24 hours. Early transition to spontaneous respiration increases the duration of artificial ventilation and worsens neurological symptoms.