Effects of Volume Guaranteed Ventilation Combined with Two Different Modes in Preterm Infants

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

BACKGROUND

National Institute for Health and Clinical Effectiveness (NICE), UK, guideline published in 2019 recommends the use of volume-targeted ventilation (VTV). It recommends synchronised intermittent mandatory ventilation (SIMV) over the modes that support-all-breaths, for example, assist control ventilation (ACV). We conducted a systematic review and meta-analysis of the studies comparing SIMV mode with triggered modes supporting all breaths.

METHODS

Patients: Neonates receiving mechanical ventilation.

INTERVENTION

SIMV ventilation.Comparison: Modes that support-all-breaths: ACV, pressure support ventilation and neurally adjusted ventilation.

OUTCOMES

Death before discharge and bronchopulmonary dysplasia (BPD) at 36 weeks' corrected gestation, weaning duration, incidence of air leaks, extubation failure, postnatal steroid use, patent ductus arteriosus requiring treatment, severe (grade 3/4) intraventricular haemorrhage, periventricular leukomalacia and neurodevelopmental outcome at 2 years.Randomised or quasi-randomised clinical trials comparing SIMV with triggered ventilation modes supporting all breaths in neonates, reporting on at least one outcome of interest were eligible for inclusion in the review.

RESULTS

Seven publications describing eight studies fulfilled the eligibility criteria. No significant difference in mortality (OR 0.74, 95% CI 0.32 to 1.74) or BPD at 36 weeks (OR 0.63, 95% CI 0.33 to 1.24), but the weaning duration was significantly shorter in support-all-breaths group with a mean difference of -22.67 hours (95% CI -44.33 to -1.01). No difference in any other outcomes.

CONCLUSION

Compared with SIMV, synchronised modes supporting all breaths are associated with a shorter weaning duration with no statistically significant difference in mortality, BPD at 36 weeks or other outcomes. Larger studies with explicit ventilator and weaning protocols are needed to compare these modes in the current neonatal population.

PROSPERO REGISTRATION NUMBER

The review was prospectively registered with PROSPERO: CRD42020207601.

Analysis of predictive parameters for extubation in very low birth weight preterm infants

BACKGROUND

Mechanical ventilation is the primary treatment for preterm infants with respiratory failure. Prolonged intubation may lead to complications; thus, early extubation is desirable. No standard criteria exist for determining the appropriateness of extubating very-low-birth-weight (VLBW) infants. This study explored the predictors of successful extubation in preterm VLBW infants.

METHODS

This retrospective cohort study included 60 preterm VLBW infants who underwent their first extubation in the neonatal intensive care unit in a regional hospital in Hsinchu, Taiwan, between January 2017 and November 2020. Successful extubation was defined as having no requirement of reintubation within 3 days of extubation. Potentially predictive variables, including demographics, prenatal characteristics, and ventilator parameters were compared between a successful extubation group and failed extubation group.

RESULTS

Of the 60 infants, 47 (78.33%) underwent successful extubation. The successful extubation group had higher Apgar scores at 1 (7 vs. 6, P = 0.02) and 5 min (9 vs. 7, P = 0.007) than those of the failed extubation group. Ventilator inspiratory pressure and mean airway pressure were significantly lower at 24, 16, 8, and 1 h before extubation and upon its completion in the successful extubation group. The areas under a number of the receiver operating characteristic curve curves in this study were moderate, specifically, 0.72, 0.74, and 0.69. Statistical analysis revealed an association between ventilator parameters before 1 h extubation (IP > 17.5cmH₂O, MAP >7.5 cmH₂O, RSS >1.82) and extubation failure (odds ratio 1.73, 2.27, 2.46 and 95% confidence interval:1.16-2.6, 1.26-4.08, 1.06-5.68, respectively).

CONCLUSION

Higher Apgar scores at birth, lower ventilator inspiratory pressure, and mean airway pressure 24, 16, 8, and 1 h and 1 h RSS prior to extubation are associated with successful extubation in VLBW preterm infants.

New developments in neonatal respiratory management

Respiratory distress syndrome (RDS) is the major cause of respiratory failure in preterm infants due to immature lung development and surfactant deficiency. Although the concepts and methods of managing respiratory problems in neonates have changed continuously, determining appropriate respiratory treatment with minimal ventilation-induced lung injury and complications is crucially important. This review summarizes neonatal respiratory therapy's advances and available strategies (i.e., exogenous surfactant therapy, noninvasive ventilation, and different ventilation modes), focusing on RDS management.

Synchronized Invasive Mechanical Ventilation

Respiratory care of premature neonates has witnessed substantial advances in the last two decades and has played a crucial role in decreasing early mortality in this population. This review outlines advances in techniques of synchronization and modes of synchronized invasive mechanical ventilation in neonates. The use of synchronized ventilation in the neonatal population was delayed as compared to adults, mainly because of technical reasons. Coordinating the infant's respiratory effort and the onset of mechanical ventilation in the neonatal population has requested high sensitivity instruments.

A comparison of the effect of bi-level positive airway pressure and synchronized intermittent mandatory ventilation in preterm infants with respiratory distress syndrome

OBJECTIVE

Bi-level positive airway pressure (BiPAP) and synchronized intermittent mandatory ventilation (SIMV) can be used to achieve peak inspiratory pressure and positive end-expiratory pressure to avoid alveolar collapse and improve oxygenation in preterm infants during the treatment of respiratory distress syndrome (RDS), and there is an urgent demand for evaluating the effects and prognoses of these two ventilation modes.

STUDY DESIGN

We conducted a retrospective study on preterm infants (≤32 weeks and <2500 g) from March 2015 to March 2020 with BiPAP (n = 63) and SIMV (n = 63). The primary outcomes were successful treatment and weaning within 72 h, the demand for a second pulmonary surfactant supply and the need for a second respiratory support. The secondary outcome was the incidence of complications.

RESULTS

There were no significant differences (p > .05) in the primary outcomes or the incidence of complications (pneumonia, apnea, respiratory failure, air leak syndrome, persistence of patent ductus arteriosus, neonatal sepsis, necrotizing enterocolitis, retinopathy of prematurity, and intraventricular hemorrhage). There were significant differences (p < .05) in the incidence of pulmonary hemorrhage, bronchopulmonary dysplasia and IVH (≥grade II).

CONCLUSIONS

Although both BiPAP and SIMV achieved good early treatment outcomes of RDS in preterm infants, BiPAP support is recommended for reducing the incidence of pulmonary hemorrhage, bronchopulmonary dysplasia and IVH (≥grade II) if infants are tolerant. Attempts should be made to prevent these complications from happening with the use of SIMV support if infants are intolerant.

Evaluating peak inspiratory pressures and tidal volume in premature neonates on NAVA ventilation

Neurally adjusted ventilatory assist (NAVA) ventilation allows patients to determine their peak inspiratory pressure and tidal volume on a breath-by-breath basis. Apprehension exists about premature neonates' ability to self-regulate breath size. This study describes peak pressure and tidal volume distribution of neonates on NAVA and non-invasive NAVA. This is a retrospective study of stored ventilator data with exploratory analysis. Summary statistics were calculated. Distributional assessment of peak pressure and tidal volume were evaluated, overall and per NAVA level. Over 1 million breaths were evaluated from 56 subjects. Mean peak pressure was 16.4 ± 6.4 in the NAVA group, and 15.8 ± 6.4 in the NIV-NAVA group (t test, p < 0.001). Mean tidal volume was 3.5 ± 2.7 ml/kg.Conclusion:In neonates on NAVA, most pressures and volumes were within or lower than recommended ranges with pressure-limited or volume-guarantee ventilation. What is known: • Limiting peak inspiratory pressures or tidal volumes are the main strategies to minimize ventilator-induced lung injury in neonates. Neurally adjusted ventilatory assist allows neonates to regulate their own peak inspiratory pressures and tidal volumes on a breath-to-breath basis using neural feedback. What is new: • When neonates chose the size of their breaths based on neural feedback, the majority of peak inspiratory pressures and tidal volumes were within or lower than the recommended peak inspiratory pressure or tidal volume ranges with pressure-limited or volume guarantee ventilation.

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

BACKGROUND

Pressure rise time (PRT), also known as slope time to the peak inflating pressure can be set on some modern neonatal ventilators. On other ventilators, PRT is determined by the set circuit flow. Changing slope time can affect mean airway pressure (MAP), oxygenation, and carbon dioxide elimination. Our aim was to investigate the effect of PRT on ventilator parameters and gas exchange during volume-guaranteed ventilation.

METHODS

In a crossover study, 12 infants weighing greater than 2 kg were ventilated using a Dräger Babylog VN500 ventilator with synchronized intermittent positive pressure ventilation with volume guarantee (SIPPV-VG) and pressure support ventilation with volume guarantee (PSV-VG). During both modes PRTs between 0.08 and 0.40 seconds were used in 15-minute epochs. Data from the ventilator and patient monitors were downloaded with 1- and 100-Hz sampling rate and analyzed using the Python computer language.

RESULTS

During PSV-VG, longer PRTs were associated with longer inspiratory time (P < .0001) and with lower peak inflating pressure (PIP; P = .003), but the MAP was similar. During SIPPV-VG the PIP was not significantly different; however, MAP was lower with longer PRT (P = .001). With a short PRT (0.08 seconds), the PIP was higher during PSV-VG than during SIPPV-VG (19.8 vs 16.5 mbar; P = .042). There were no significant differences in tidal volume delivery, respiratory rate, minute volume, oxygen saturations, or end-tidal CO₂ with different PRTs in either mode.

CONCLUSIONS

During SIPPV-VG or PSV-VG, using short or long PRTs affects some ventilation parameters but does not significantly change oxygenation or carbon dioxide elimination.

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.

European Consensus Guidelines on the Management of Respiratory Distress Syndrome - 2019 Update

As management of respiratory distress syndrome (RDS) advances, clinicians must continually revise their current practice. We report the fourth update of "European Guidelines for the Management of RDS" by a European panel of experienced neonatologists and an expert perinatal obstetrician based on available literature up to the end of 2018. Optimising outcome for babies with RDS includes prediction of risk of preterm delivery, need for appropriate maternal transfer to a perinatal centre and timely use of antenatal steroids. Delivery room management has become more evidence-based, and protocols for lung protection including initiation of CPAP and titration of oxygen should be implemented immediately after birth. Surfactant replacement therapy is a crucial part of management of RDS, and newer protocols for its use recommend early administration and avoidance of mechanical ventilation. Methods of maintaining babies on non-invasive respiratory support have been further developed and may cause less distress and reduce chronic lung disease. As technology for delivering mechanical ventilation improves, the risk of causing lung injury should decrease, although minimising time spent on mechanical ventilation using caffeine and, if necessary, postnatal steroids are also important considerations. Protocols for optimising general care of infants with RDS are also essential with good temperature control, careful fluid and nutritional management, maintenance of perfusion and judicious use of antibiotics all being important determinants of best outcome.

[A comparative study of two ventilation modes in the weaning phase of preterm infants with respiratory distress syndrome]

OBJECTIVE

To compare the efficacy between synchronized intermittent mandatory ventilation (SIMV) and pressure support ventilation with volume guarantee (PSV+VG) in the weaning phase of preterm infants with respiratory distress syndrome (RDS).

METHODS

Forty preterm infants with RDS who were admitted to the neonatal intensive care unit between March 2016 and May 2017 were enrolled as subjects. All infants were born at less than 32 weeks' gestation and received mechanical ventilation. These patients were randomly and equally divided into SIMV group and PSV+VG group in the weaning phase. Ventilator parameters, arterial blood gas, weaning duration (from onset of weaning to extubation), duration of nasal continuous positive airway pressure (NCPAP) after extubation, extubation failure rate, the incidence rates of pneumothorax, patent ductus arteriosus (PDA) and bronchopulmonary dysplasia (BPD), and the mortality rate were compared between the two groups.

RESULTS

The PSV+VG group had significantly decreased mean airway pressure, weaning duration, duration of NCPAP after extubation, and extubation failure rate compared with the SIMV group (P<0.05). There were no significant differences in arterial blood gas, mortality, or incidence rates of pneumothorax, PDA and BPD between the two groups (P>0.05).

CONCLUSIONS

For preterm infants with RDS, the PSV+VG mode may be a relatively safe and effective mode in the weaning phase. However, multi-center clinical trials with large sample sizes are needed to confirm the conclusion.