High-Frequency Oscillatory Ventilation with Low Oscillatory Frequency in Pulmonary Interstitial Emphysema

Abstract

Background: Pulmonary interstitial emphysema (PIE) is a common respiratory illness in preterm infants associated with significant morbidity and mortality for which the ventilatory management is imperfect. Objectives: To evaluate the impact of high-frequency oscillatory ventilation (HFOV) with a low oscillatory frequency and thus prolonged expiratory time in preterm infants with severe PIE. Methods: In a retrospective cohort study, preterm infants ≤30 weeks' gestation with radiological findings of severe PIE, and either high FiO₂ or persistent respiratory acidosis were studied if managed on HFOV with a low frequency (5-6 Hz, inspiratory time 30%) for >24 h. Trends in physiological and ventilatory parameters were examined over the first 72 h, radiological changes noted, and in-hospital outcomes ascertained. Results: 19 cases were identified and analysed in two groups: 14 with bilateral and 5 with predominantly unilateral disease. After transition to low-frequency HFOV, physiological responses were seen in both groups, in particular a rapid and sustained improvement in oxygenation in the bilateral group (mean (SD) alveolar-arterial oxygen difference at baseline: 404 ± 206 mm Hg; 4 h post-transition: 262 ± 181 mm Hg; 72 h: 155 ± 74 mm Hg; p = 0.0003). This occurred following a reduction in mean airway pressure (mean (SD) baseline: 14 ± 3.9 cm H₂O; 72 h: 12 ± 2.9 cm H₂O; p = 0.011). In the unilateral group, radiological resolution of PIE was observed on re-inflation following collapse of the affected lung. Overall, 15 infants survived, including 10 of the bilateral cases (71%), and all of the unilateral cases. Conclusion: HFOV with a low oscillatory frequency may afford benefit in preterm babies with severe PIE.

Assessing Initial Response to High-Frequency Jet Ventilation in Premature Infants With Hypercapnic Respiratory Failure

“…17,18 The majority of randomized control trials reported using HFOV frequencies between 10 and 15 Hz in premature infants with respiratory failure. 4 Squires et al 19 describe the utilization of lower HFOV frequencies (5-6 Hz) to afford a longer expiratory phase in infants with pulmonary interstitial emphysema and concluded that this strategy may provide some benefit in gas exchange. Reducing HFOV frequency concomitantly increases the inspiratory time, results in larger V T , and could potentially exacerbate lung injury in infants with low lung compliance.…”

Meconium Aspiration Syndrome: Possible Pathophysiological Mechanisms and Future Potential Therapies

“…High-frequency oscillatory ventilation may be beneficial in clinical MAS complicated by pulmonary interstitial emphysema [20]. Zagariya et al [21] used an animal model and compared the effects of saline, milk and meconium instillation into the rabbit lungs.…”

Acquired neonatal bronchial stenosis after selective intubation: Successful managed with balloon dilatation

“…For selective intubation to be successful, the tip of the endotracheal tube (ETT) must be passed into the opening of the right main bronchus and kept in that position to facilitate collapse of the left lung. The duration of this procedure depends on how quickly the lung collapses and if the baby can tolerate single lung ventilation.The preferred duration of selective main stem intubation reported in the literature varies arbitrarily from 1 to 10 days . In some cases, the combination of selective intubation and HFOV have been used with an approach of low oscillatory frequency and a reduced mean airway pressure .…”

“…The duration of this procedure depends on how quickly the lung collapses and if the baby can tolerate single lung ventilation.The preferred duration of selective main stem intubation reported in the literature varies arbitrarily from 1 to 10 days . In some cases, the combination of selective intubation and HFOV have been used with an approach of low oscillatory frequency and a reduced mean airway pressure . This is important in the management of PIE as this decreases the driving pressure of the gas through the leak site.…”