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ABSTRACT: Design
Prospective observational study.Setting
Regional quaternary teaching hospital neonatal ICU.Patients
Thirteen term or near-term infants receiving high-frequency oscillatory ventilation and muscle relaxants.Interventions
One to two cm H2O mean airway pressure changes every 10 minutes as part of an open lung strategy based on oxygen response.Measurements and main results
Continuous lung volume measurements (respiratory inductive plethysmography) were made during the mean airway pressure changes. Volume signals were analyzed with a biexponential model to calculate the time to stable lung volume if the model R 2 was greater than 0.6. If volume stability did not occur within 10 minutes, the model was extrapolated to maximum 3,600 s. One-hundred ninety-six mean airway pressure changes were made, with no volume change in 33 occurrences (17%). One-hundred twenty-five volume signals met modeling criteria for inclusion; median (interquartile range) R 2, 0.96 (0.91-0.98). The time to stable lung volume was 1,131 seconds (718-1,959 s) (mean airway pressure increases) and 647 seconds (439-1,309 s) (mean airway pressure decreases), with only 17 (14%) occurring within 10 minutes and time to stability being longer when the lung was atelectatic.Conclusions
During high-frequency oscillatory ventilation, the time to stable lung volume after a mean airway pressure change is variable, often requires more than 10 minutes, and is dependent on the preceding volume state.
SUBMITTER: Tingay DG
PROVIDER: S-EPMC8205213 | biostudies-literature | 2021 Jun
REPOSITORIES: biostudies-literature
Tingay David G DG Kiraly Nicholas N Mills John F JF Dargaville Peter A PA
Critical care explorations 20210614 6
Clinicians have little guidance on the time needed before assessing the effect of a mean airway pressure change during high-frequency oscillatory ventilation. We aimed to determine: 1) time to stable lung volume after a mean airway pressure change during high-frequency oscillatory ventilation and 2) the relationship between time to volume stability and the volume state of the lung.<h4>Design</h4>Prospective observational study.<h4>Setting</h4>Regional quaternary teaching hospital neonatal ICU.<h ...[more]