Flow-synchronized ventilation of preterm infants with respiratory distress syndrome. Randomised trial of volume controlled versus time cycled, pressure limited ventilation in preterm infants with respiratory distress syndrome. Flow-cycled versus time-cycled sIPPV in preterm babies with RDS: a breath-to-breath randomised cross-over trial. Patient-initiated, pressure-regulated, volume-controlled ventilation compared with intermittent mandatory ventilation in neonates: a prospective, randomised study. Comparison of synchronized and conventional intermittent mandatory ventilation in neonates. Randomized, multicenter trial of conventional ventilation versus high-frequency oscillatory ventilation for the early management of respiratory failure in term or near-term infants in Colombia. Prospective clinical comparison of two methods for mechanical ventilation of neonates: rapid rate and short inspiratory time versus slow rate and long inspiratory time. The Provo multicenter early high-frequency oscillatory ventilation trial: improved pulmonary and clinical outcome in respiratory distress syndrome. Randomized comparison of high-frequency ventilation with high-rate intermittent positive pressure ventilation in preterm infants with respiratory failure.
Asynchrony of delivered and spontaneous breaths in mechanically ventilated infants may impair gas exchange and prolong the need for assisted ventilation. We conducted a randomized, controlled trial of a patient-triggered, flow-synchronized ventilator on 30 preterm infants with respiratory distress syndrome who weighed between 1100 and 1500 gm at birth. Entry criteria included radiographic evidence of respiratory distress syndrome and the need for mechanical ventilation and surfactant replacement therapy. Patients were assigned to either conventional time-cycled, pressure-limited ventilation or patient-triggered, flow-synchronized ventilation in an assist/control mode. Otherwise clinical management was identical. Time to extubation was the primary outcome measure. Patients treated with flow-synchronized ventilation were weaned more rapidly and had a significantly shorter mean time to extubation than those treated with time-cycled, pressure-limited ventilation, 119 versus 271 hours, p = 0.0152. In addition, there was no difference in the rate of complications between the two groups. There were, however, considerable reductions in patient charges of $4344 per patient in the flow-synchronized ventilation group. Fifty preterm infants weighing 1200 g or more with clinical and radiographic evidence of respiratory distress syndrome, requiring both mechanical ventilation and exogenous surfactant replacement, were randomly allocated to receive either volume controlled ventilation or time cycled, pressure limited ventilation. Tidal volume delivery in each group was deliberately controlled at 5-8 ml/kg so that the only difference between the two groups was the ventilatory modality, the manner in which tidal volume was delivered. The rest of the ventilatory management and clinical care was done according to protocol. The two modes of ventilation were compared by determining the time required to achieve pre-determined success criteria, based on either the alveolar-arterial oxygen gradient or the mean airway pressure as a standard against which the speed of weaning could be objectively assessed. Infants randomised to volume controlled ventilation met success criteria sooner and had a shorter duration of mechanical ventilation. These babies also had a significantly lower incidence of intraventricular haemorrhages and abnormal periventricular echodensities on ultrasound scans. Volume controlled ventilation seems to be both safe and effective in this group of patients. Few data exist about patient-triggered ventilation techniques in neonatal critical care. Our aim was to compare pressure-limited synchronised intermittent positive pressure (or assist/control) ventilation (sIPPV) in the classical time-cycled (TC-sIPPV) mode against flow-cycled (FC-sIPPV) modality. In this latter, typical sIPPV full respiratory support is provided but both the initiation and the end of inflation are determined by the infant's spontaneous respiratory efforts by using airway flow changes.
                A third-level neonatal intensive care unit.
                Ten preterm babies (<32 weeks' gestation) were randomised to receive 1 h FC-sIPPV followed by 1 h TC-sIPPV or the inverse shift, according to a computer-created randomisation table. Eligible babies had hyaline membrane disease and received 200 mg/kg surfactant at least 6 h before the study period. Respiratory mechanics, ventilatory and vital parameter data were registered real time.
                FC-sIPPV resulted in lower-rate volume ratio, pressure x rate product, mean airway pressure and heart rate; tidal volume and oxygen saturation were higher (all p<0.001). Spontaneous inspiratory time was lower than usually set by the physician and it was directly correlated to birth weight (rho = 0.5, p = 0.001) and gestational age (rho = 0.32, p = 0.001). No differences were noticed in the mechanics and blood gas and vital parameters during the two study phases.
                FC-sIPPV may safely result in a better patient ventilator synchrony. Inspiratory time usually set in neonatal critical care is higher than that decided by the baby during spontaneous effort. This should be considered when establishing time-cycled ventilation. To compare the effects of patient-initiated, pressure-regulated, volume-controlled ventilation (PRVC) with pressure-preset intermittent mandatory ventilation (IMV) in neonates with respiratory failure.
                Randomised, prospective study.
                Intensive care unit (14 beds) in a 300-bed paediatric teaching hospital.
                60 neonates with respiratory distress syndrome (RDS) or congenital pneumonia, weighing < 2500 g and requiring mechanical ventilation.
                Ventilatory support until extubation via either IMV (n = 30) or PRVC (n = 27). In PRVC, the tidal volume (VT) was preset and pressure-controlled breaths delivered with peak inspiratory pressure values adapted to achieve the preset VT.
                Main outcome measures were duration of ventilation and incidence of bronchopulmonary dysplasia (BPD). Pulmonary air leaks and intraventricular haemorrhage (IVH) were considered major adverse effects. Demographic data, ventilation parameters and arterial/alveolar oxygen tension ratio were similar at randomisation. Duration of ventilation and incidence of BPD were not decreased by the use of PRVC. Air leaks occurred in 3 neonates in the PRVC group and in 7 babies treated with IMV (NS). The incidence of IVH grade > II was lower in babies treated with PRVC (p < 0.05). In a subgroup of neonates weighing < 1000 g, the duration of ventilation and incidence of hypotension were reduced in the PRVC group (p < 0.05).
                Patient-initiated, pressure-regulated, volume-controlled ventilation can be safely used in neonates and may contribute to a lower incidence of complications. Between October 1993 and April 1995, a total of 77 neonates requiring mechanical ventilation were enrolled in this study and were randomly divided into two groups. Group A consisted of 31 premature infants (mean birthweight 1.36 +/- 0.29 kg) with respiratory distress syndrome (RDS) and seven neonates (mean birthweight 3.2 +/- 0.5 kg) with meconium aspiration syndrome (MAS). Group B consisted of 31 premature infants (mean birthweight 1.31 +/- 0.3 kg) with RDS and eight neonates (mean birthweight 3.3 +/- 0.5 kg) with MAS. Infants in group A received synchronized intermittent mandatory ventilation (SIMV) and infants in group B received conventional intermittent mandatory ventilation (CIMV) therapy. In premature infants with RDS, our data showed: (i) the duration of ventilation was significantly shorter (P < 0.05) in the synchronized group (156 +/- 122 h) compared to the conventional group (242 +/- 175 h); (ii) significantly fewer (P < 0.05) patients required reintubation in the synchronized group than in the conventional group (three vs 11 patients); (iii) incidence of severe intraventricular hemorrhage (grades 3 and 4) was significantly lower (P < 0.05) in the synchronized group compared to the conventional group (one vs seven patients); (iv) incidence of bronchopulmonary dysplasia was significantly lower (P < 0.05) in the synchronized group than in the control group (one vs seven patients). In neonates with MAS, our data showed no significant difference (P < 0.05) on duration of ventilation, incidence of reintubation, incidence of pneumothorax or mortality rate between synchronized and control groups. To determine the efficacy and safety of high-frequency oscillatory ventilation (HFOV) compared to conventional ventilation (CV) for the treatment of respiratory failure in term and near-term infants in Colombia.
                Eligible infants with moderate to severe respiratory failure were randomized to early treatment with CV or HFOV. Ventilator management and general patient care were standardized. The main outcome was neonatal death or pulmonary air leak.
                A total of 119 infants were enrolled (55 in the HFOV group; 64 in the CV group) during the study period. Six infants in the HFOV group (11%) and two infants in the CV group (3%) developed the primary outcome (RR: 3.6, 95% CI: 0.8-16.9). Five infants in the HFOV group (9%) and one infant in the CV (2%) died before 28 days of life (RR: 5.9 CI: 0.7-48.2). Secondary outcomes were similar between groups.
                HFOV may not be superior to CV as an early treatment for respiratory failure in this age group. Standardization of ventilator management and general patient care may have a greater impact on the outcome in Colombia than mode of ventilation.
                Journal of Perinatology (2005) 25, 720-724. doi:10.1038/sj.jp.7211386; published online 15 September 2005. A prospective comparison was made of the clinical courses of two groups of neonates ventilated according to different protocols: one group at rates of 20 to 40/minute with a one-second IT, and the other at a rate of 60/minute and 0.5 second IT. Other ventilator settings were adjusted within protocol limits to maintain desired blood gas values. Mean starting and highest PIP were lower in the rapid rate group. The results showed no difference in mortality, failure to remain within protocol limits, time requiring respiratory treatment or FiO2 more than 0.6, and incidence of PDA or chronic lung disease. There was a difference (P = 0.011) in number of infants developing pneumothoraces (14% in the rapid group vs 35% in the slow group). Rapid rate ventilation can be used to decrease the incidence of pneumothorax, reserving long IT and higher PIP for infants who cannot be oxygenated or ventilated without them. To compare the hospital course and clinical outcome of preterm infants with respiratory distress syndrome treated with surfactant and managed with high-frequency oscillatory ventilation (HFOV) or conventional mechanical ventilation (CV) as their primary mode of ventilator support.
                A prospective randomized clinical trial.
                Three community-based level III neonatal intensive care units.
                A total of 125 neonates who were 35 weeks or less estimated gestation requiring intubation and assisted ventilation for respiratory distress syndrome with arterial to alveolar oxygen ratio less than .50.
                Patients were randomized to continue CV (61 patients) or be changed to HFOV (64 patients) after exogenous surfactant administration (100 mg/kg). HFOV was used in a strategy to promote lung recruitment and maintain lung volume. Protocol respiratory care guidelines were followed; otherwise routine care was provided by each neonatal intensive care unit.
                No differences were noted in demographic features between the two study groups. The study population birth weight was 1.51 +/- .47 kg (mean +/- SD), gestational age was 30.9 +/- 2.5 weeks, and study entry age was 2 to 3 hours. Patients randomized to HFOV demonstrated the following significant findings compared with CV-treated patients: vasopressor support was less intensive; surfactant redosing was not as frequent; oxygenation improved more rapidly and remained higher during the first 7 days; fewer infants required prolonged supplemental oxygen or ventilator support; treatment failure was reduced; more patients survived without chronic lung disease at 30 days; need for continuous supplemental oxygen at discharge was less; frequency of necrotizing enterocolitis illness was lower; there were fewer abnormal hearing tests; and hospital costs were decreased. No differences were seen between the two study groups in the frequency or severity of patent ductus arteriosus, air leak, retinopathy of prematurity, or intraventricular hemorrhage. Length of hospital stay and survival to discharge were similar for HFOV- and CV-treated infants.
                When used early with a lung recruitment strategy, HFOV after surfactant replacement resulted in clinical outcomes consistent with a reduction in both acute and chronic lung injury. Benefit was evident for preterm infants both less than or equal to 1 kg and more than 1 kg. In addition, early HFOV treatment may have had a more global effect on patient health throughout the hospitalization, resulting in reduced morbidity and decreased health care cost. In a randomized, controlled, multicenter trial, we tested the hypothesis that high-frequency ventilation (HFV) with a high lung volume strategy results in fewer treatment failures than intermittent positive pressure ventilation (IPPV) with high rates and low peak inspiratory pressures.
                Infants with a gestational age between >/=24 weeks and <30 weeks, requiring mechanical ventilation within 6 hours of birth, were randomly assigned to receive either IPPV or HFV until 240 hours after randomization, extubation, or meeting treatment failure criteria. Treatment failure, the primary end point, was determined when air leaks, an oxygenation index >35 to 45 (depending on gestational age), death, or chronic lung disease occurred. Chronic lung disease was defined as persistent requirement of mechanical ventilation, continuous positive airway pressure, or supplemental oxygen at a postmenstrual age of 36 weeks. Secondary end points included the incidence of intracranial hemorrhage.
                The third scheduled interim analysis led to termination of the trial after recruitment of 284 infants. Treatment failure criteria were met by 46% of infants receiving IPPV and 54% of infants receiving HFV (1-tailed primary hypothesis, P =.92; 2-tailed chi2 test, P =.15). Air leaks occurred in 31% and 42% (P =.042), CLD in 23% and 25%, and grade 3-4 intracranial hemorrhage in 13% and 14% of IPPV-treated and HFV-treated patients, respectively. The mortality rate before discharge was 10% in both groups.
                HFV with a high lung volume strategy did not cause less lung injury in preterm infants than IPPV with a high rate and low peak inspiratory pressures.
There is insufficient evidence to determine the safety and efficacy of flow-cycled compared to time-cycled synchronized ventilation in neonates. Large randomized clinical trials using a parallel-group design and reporting on clinically important outcomes are warranted.