Mechanical ventilation with high positive end-expiratory pressure and small driving pressure amplitude is as effective as high-frequency oscillatory ventilation to preserve the function of exogenous surfactant in lung-lavaged rats

Abstract Primary Subject area Neonatal-Perinatal Medicine Background Mechanical ventilation is frequently used in preterm infants for various indications, but is associated with multiple complications, including bronchopulmonary dysplasia and poorer neurodevelopmental outcomes. Noninvasive high-frequency oscillatory ventilation (nHFOV) is a noninvasive ventilation (NIV) strategy used to avoid mechanical ventilation and associated complications. However, its effectiveness remains controversial, and its safety has not been established. Objectives The objectives were to evaluate the effectiveness of nHFOV to prevent intubations and support adequate ventilation in preterm infants, and to assess its safety profile. Design/Methods This was a retrospective crossover case study including 24 infants and 30 nHFOV instances between May 2018 and June 2020. Infants were included if they were placed on nHFOV for at least one hour; each nHFOV trial contributed as one instance. Data was collected from health records. Effectiveness outcomes were: successful transition to another NIV mode without requiring intubation, and variations in CO2, FiO2, and number of spells. Safety outcomes were: apparition of intraventricular hemorrhage (IVH), gastrointestinal complications, nasal cutaneous trauma, and comfort as assessed with the Neonatal Pain, Agitation and Sedation Scale (N-PASS). Descriptive statistics were used for baseline characteristics. Nonparametric and semiparametric tests were used to compare outcomes pre- and during nHFOV. Results Baseline characteristics are presented in Table 1. At initiation of nHFOV, mean chronological age and weight were 24 days (95% CI: 20 – 28) and 1119 grams (95% CI: 1038 – 1200) respectively. The most frequent indication for nHFOV was spells (56.7%), and the mean duration of nHFOV instances was 3.9 days (95% CI: 2.7 – 5.1) (Table 1). In 18 (60%) cases, infants transitioned successfully to another NIV mode without requiring intubation. Levels of CO2 and number of spells were significantly lower during nHFOV than pre-nHFOV. There was no significant difference in FiO2 pre-nHFOV and during nHFOV. No apparition or progression of IVH was observed following the use of nHFOV. There was no significant difference in N-PASS, nasal trauma, and gastrointestinal complications pre-nHFOV and during nHFOV (Table 2). Conclusion This study suggests that nHFOV is an effective ventilation method to avoid intubation and to decrease spells in preterm infants, without increasing complications.

Download Full-text

Physiologic responses to a staircase lung volume optimization maneuver in pediatric high-frequency oscillatory ventilation

Annals of Intensive Care ◽

10.1186/s13613-020-00771-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Pauline de Jager ◽

Johannes G. M. Burgerhof ◽

Alette A. Koopman ◽

Dick G. Markhorst ◽

Martin C. J. Kneyber

Keyword(s):

Tidal Volume ◽

Lung Volume ◽

High Frequency ◽

Hemodynamic Instability ◽

High Frequency Oscillatory Ventilation ◽

Pressure Amplitude ◽

Oscillatory Ventilation ◽

Arterial Blood ◽

Respiratory Inductance Plethysmography ◽

High Frequency Oscillatory

Abstract Background Titration of the continuous distending pressure during a staircase incremental–decremental pressure lung volume optimization maneuver in children on high-frequency oscillatory ventilation is traditionally driven by oxygenation and hemodynamic responses, although validity of these metrics has not been confirmed. Methods Respiratory inductance plethysmography values were used construct pressure–volume loops during the lung volume optimization maneuver. The maneuver outcome was evaluated by three independent investigators and labeled positive if there was an increase in respiratory inductance plethysmography values at the end of the incremental phase. Metrics for oxygenation (SpO2, FiO2), proximal pressure amplitude, tidal volume and transcutaneous measured pCO2 (ptcCO2) obtained during the incremental phase were compared between outcome maneuvers labeled positive and negative to calculate sensitivity, specificity, and the area under the receiver operating characteristic curve. Ventilation efficacy was assessed during and after the maneuver by measuring arterial pH and PaCO2. Hemodynamic responses during and after the maneuver were quantified by analyzing heart rate, mean arterial blood pressure and arterial lactate. Results 41/54 patients (75.9%) had a positive maneuver albeit that changes in respiratory inductance plethysmography values were very heterogeneous. During the incremental phase of the maneuver, metrics for oxygenation and tidal volume showed good sensitivity (> 80%) but poor sensitivity. The sensitivity of the SpO2/FiO2 ratio increased to 92.7% one hour after the maneuver. The proximal pressure amplitude showed poor sensitivity during the maneuver, whereas tidal volume showed good sensitivity but poor specificity. PaCO2 decreased and pH increased in patients with a positive and negative maneuver outcome. No new barotrauma or hemodynamic instability (increase in age-adjusted heart rate, decrease in age-adjusted mean arterial blood pressure or lactate > 2.0 mmol/L) occurred as a result of the maneuver. Conclusions Absence of improvements in oxygenation during a lung volume optimization maneuver did not indicate that there were no increases in lung volume quantified using respiratory inductance plethysmography. Increases in SpO2/FiO2 one hour after the maneuver may suggest ongoing lung volume recruitment. Ventilation was not impaired and there was no new barotrauma or hemodynamic instability. The heterogeneous responses in lung volume changes underscore the need for monitoring tools during high-frequency oscillatory ventilation.

Download Full-text