Highly comparative time series analysis of oxygen saturation and heart rate to predict respiratory outcomes in extremely preterm infants.

Highly comparative time series analysis (HCTSA) is a novel approach involving massive feature extraction using publicly available code from many disciplines. The Prematurity-Related Ventilatory Control (Pre-Vent) observational multicenter prospective study collected bedside monitor data from>700extremely preterm infants to identify physiologic features that predict respiratory outcomes..

Use of a Mechanical Ventilator with Respiratory Function Monitoring Provides More Consistent Ventilation during Simulated Neonatal Resuscitation.

Introduction: Positive pressure ventilation (PPV) with T-Piece and self-inflating bag (SIB) during neonatal resuscitation after birth is associated with variability in ventilation. The use of a ventilator with respiratory function monitoring (RFM) for PPV, however, has not been evaluated.

Objective: To determine if ventilator + RFM can reduce ventilation variability compared to T-Piece and SIB in a preterm manikin at different combinations of target tidal volume (VT) and lung compliance (CL).

Cerebral oxygenation in preterm infants receiving transfusion.

Background: The influence of severity of anemia and cardiac output (CO) on cerebral oxygenation (CrSO) and on the change in CrSO following packed red blood cell (PRBC) transfusion in preterm infants has not been evaluated. The objectives of the current study were to evaluate the effect of pre-transfusion hemoglobin (Hb) and CO-weighted oxygen delivery index (ODI) on CrSO and on the post-transfusion CrSO change.

Methods: Preterm infants of <32 weeks gestational age (GA) receiving PRBC transfusion were enrolled.

Early Caffeine and Weaning from Mechanical Ventilation in Preterm Infants: A Randomized, Placebo-Controlled Trial.

Objective: To evaluate in a randomized, double-blind, placebo-controlled trial the effect of early caffeine on the age of first successful extubation in preterm infants.

Study Design: Preterm infants born at 23-30 weeks of gestation requiring mechanical ventilation in the first 5 postnatal days were randomized to receive a 20 mg/kg loading dose followed by 5 mg/kg/day of caffeine or placebo until considered ready for extubation. The placebo group received a blinded loading dose of caffeine before extubation.

Hypoxemia Episodes during Day and Night and Their Impact on Oxygen Saturation Targeting in Mechanically Ventilated Preterm Infants.

Background: Hypoxemia episodes (HE) occur frequently in ventilated preterm infants and hinder the achievement of arterial oxygen saturation (SpO2) targets. These episodes may increase the risk for retinopathy of prematurity and neurodevelopmental disability. There are no data on the variation in HE and SpO2 targeting between day and night.

Volume Guarantee Ventilation: Effect on Preterm Infants with Frequent Hypoxemia Episodes.

Background: Preterm infants on mechanical ventilation have spontaneous hypoxemia episodes (HE) triggered by decreases in lung volume and tidal volume (VT). Volume guarantee (VG) is a mode where the ventilator peak pressure is adjusted to keep the exhaled VT at a target level. The effect of VG on HE under routine clinical conditions has not been fully evaluated.

Effect of positive end-expiratory pressure on ductal shunting and systemic blood flow in preterm infants with patent ductus arteriosus.

Background: Left to right (L-R) shunting through a patent ductus arteriosus (PDA) can reduce systemic and cerebral blood flow in preterm infants. To minimize this, the positive end-expiratory pressure (PEEP) is often raised to increase pulmonary vascular resistance and reduce L-R shunting. The effects of this maneuver on systemic and cerebral hemodynamics and oxygenation are not well documented.

A randomized controlled trial of two nasal continuous positive airway pressure levels after extubation in preterm infants.

Objective: To compare extubation failure rate with two ranges of nasal continuous positive airway pressure (NCPAP) in oxygen dependent preterm infants.

Study Design: Preterm infants of birth weight 500-1000 g and gestational age 23-30 weeks, extubated for the first time during the first 6 weeks while requiring fraction of inspired oxygen ≥ 0.25, were randomly assigned to a NCPAP range of 4-6 (low NCPAP) or 7-9 (high NCPAP) cmH2O.

Multicenter crossover study of automated control of inspired oxygen in ventilated preterm infants.

Objective: To determine the efficacy and safety of automated adjustment of the fraction of inspired oxygen (Fio(2)) adjustment in maintaining arterial oxygen saturation (Spo(2)) within an intended range for mechanically ventilated preterm infants with frequent episodes of decreased Spo(2).

Methods: Thirty-two infants (gestational age [median and interquartile range]: 25 weeks [24-27 weeks]; age: 27 days [17-36 days]) were studied during 2 consecutive 24-hour periods, one with Fio(2) adjusted by clinical staff members (manual) and the other by an automated system (automated), in random sequence.

Results: Time with Spo(2) within the intended range (87%-93%) increased significantly during the automated period, compared with the manual period (40% ± 14% vs 32% ± 13% [mean ± SD]).

Effects of synchronization during nasal ventilation in clinically stable preterm infants.

Nasal ventilation is increasingly used to reduce invasive ventilation in preterm infants. The effects of nasal ventilation and the advantages of synchronized nasal ventilation have not been fully evaluated. The objective was to compare the short-term effects of nasal intermittent mandatory ventilation (NIMV) and synchronized NIMV (S-NIMV) with nasal continuous positive airway pressure (NCPAP) on ventilation, gas exchange, and infant-ventilator interaction.

Automated adjustment of inspired oxygen in preterm infants with frequent fluctuations in oxygenation: a pilot clinical trial.

Objective: To assess the efficacy of a system for automated fraction of inspired oxygen (FiO(2)) adjustment in maintaining oxygen saturation (SpO(2)) within an intended range in preterm infants with spontaneous fluctuations in SpO(2).

Study Design: Sixteen infants (gestational age, 24.9 +/- 1.

Targeted minute ventilation and tidal volume in an animal model of acute changes in lung mechanics and episodes of hypoxemia.

Background: Acute episodes of hypoxemia in ventilated preterm infants are triggered by changes in ventilation, lung volume (LV) and respiratory system compliance (C(RS)) that are not prevented by conventional synchronized intermittent mandatory ventilation (SIMV).

Objective: To assess in a rabbit model of episodic hypoxemia the individual and combined efficacy of targeted tidal volume (V(T)) and minute ventilation (V'(E)) by automatic adjustment of peak inspiratory pressure (PIP) and ventilator rate, respectively.

Methods: Six young New Zealand white rabbits were ventilated with SIMV, targeted V(T), targeted V'(E), and combined targeted V'(E) + V(T) in random sequence.

Mechanisms of hypoxemia episodes in spontaneously breathing preterm infants after mechanical ventilation.

Background: Preterm infants often present with recurrent episodes of hypoxemia after mechanical ventilation.

Objective: To evaluate the role of abdominal muscle activity and central apnea on the frequency and severity of hypoxemia episodes (HEs) in preterm infants with a history of mechanical ventilation.

Methods: Continuous recordings of arterial oxygen saturation (SpO(2)), gastric pressure, respiratory inductance plethysmography and abdominal surface electromyography were obtained during 4 h from spontaneously breathing preterm infants who had recently been extubated and presented with frequent HEs.

Effects of non-invasive pressure support ventilation (NI-PSV) on ventilation and respiratory effort in very low birth weight infants.

Background: Nasal continuous positive airway pressure (NCPAP) is used to provide support to non-intubated infants, but it often fails. Pressure support ventilation (PSV) is a mode of synchronized ventilation that can supplement the spontaneous breathing effort, but it is unknown if it is effective in non-intubated very low birth weight (VLBW) infants.

Objectives: To compare the acute physiological effects of non-invasive PSV (NI-PSV) versus NCPAP on tidal volume (V(T)), minute ventilation (V(E)), gas exchange, breathing effort, and chest wall distortion in VLBW infants.

Role of abdominal muscles activity on duration and severity of hypoxemia episodes in mechanically ventilated preterm infants.

Background: Episodes of hypoxemia are often observed in ventilated preterm infants. The factors that determine their duration, severity and the failure of the mechanical breaths to maintain ventilation have not been fully defined.

Objective: To determine the relation between activity of the abdominal muscles and the duration and severity of hypoxemia episodes in ventilated preterm infants.

Randomized, controlled trial comparing synchronized intermittent mandatory ventilation and synchronized intermittent mandatory ventilation plus pressure support in preterm infants.

Background: Prolonged mechanical ventilation is associated with lung injury in preterm infants. In these infants, weaning from synchronized intermittent mandatory ventilation may be delayed by their inability to cope with increased respiratory loads. The addition of pressure support to synchronized intermittent mandatory ventilation can offset these loads and may facilitate weaning.

Acute effects of PEEP on tidal volume and respiratory center output during synchronized ventilation in preterm infants.

Background: Positive end expiratory pressure (PEEP) is routinely used in mechanically ventilated preterm infants to maintain lung volume. An acute increase in PEEP can affect lung mechanics and tidal volume, but it is unknown if these effects elicit compensatory changes in respiratory center output.

Objectives: To investigate the acute effects of changes in PEEP on tidal volume (V(T)), lung compliance (C(L)), and respiratory center output (RCO) during synchronized intermittent mandatory ventilation (SIMV) in preterm infants at different levels of basal respiratory drive.

Effects of volume-targeted synchronized intermittent mandatory ventilation on spontaneous episodes of hypoxemia in preterm infants.

Background: Hypoxemic episodes in ventilated preterm infants are frequently caused by reduced ventilation due to a decrease in lung volume and acute worsening of respiratory mechanics.

Objective: To compare the efficacy of conventional time-cycled, pressure-limited flow synchronized intermittent mandatory ventilation (SIMV) and volume-targeted SIMV (VT-SIMV) in reducing the frequency and severity of these episodes.

Methods: SIMV and VT-SIMV were compared in preterm infants with frequent spontaneous episodes of hypoxemia.

Effects of pressure support during an acute reduction of synchronized intermittent mandatory ventilation in preterm infants.

Background: During weaning of synchronized intermittent mandatory rate in preterm infants, the spontaneous breaths must overcome the resistance of the endotracheal tube and the disease-induced respiratory loads. Pressure Support (PS) can be used as an adjunct to synchronized intermittent mandatory ventilation (SIMV) to partially unload the spontaneous breaths.

Objective: To evaluate the effects of two levels of PS as an adjunct to SIMV on gas exchange and breathing effort during an acute reduction in SIMV rate in preterm infants.

Acute effects of inhaled nitric oxide on pulmonary and cardiac function in preterm infants with evolving bronchopulmonary dysplasia.

Background: Inhaled nitric oxide (iNO) reduces pulmonary vascular resistance by preferential vasodilation in ventilated lung units. In experimental animals, iNO also reduces airway resistance by smooth muscle relaxation. Hence, there may be a therapeutic role for iNO in evolving bronchopulmonary dysplasia (BPD).

Elimination of ventilator dead space during synchronized ventilation in premature infants.

Background: Mainstream airflow sensors used in neonatal ventilators to synchronize mechanical breaths with spontaneous inspiration and measure ventilation increase dead space and may impair carbon dioxide (CO(2)) elimination.

Objective: To evaluate a technique consisting of a continuous gas leakage at the endotracheal tube (ETT) adapter to wash out the airflow sensor for synchronization and ventilation monitoring without CO(2) rebreathing in preterm infants.

Design: Minute ventilation (V'(E)) by respiratory inductance plethysmography, end-inspiratory and end-expiratory CO(2) by side-stream microcapnography, and transcutaneous CO(2) tension (TcPCO(2)) were measured in 10 infants (body weight, 835+/-244 g; gestational age, 26+/-2 weeks; age, 19+/-9 days; weight, 856+/-206 g; ventilator rate, 21+/-6 beats/min; PIP, 16+/-1 centimeters of water (cmH(2)O); PEEP, 4.