Work

Multifrequency Oscillatory Ventilation in the Premature Lung

Year: 2015

Type: article

Abstract: Abstract In preterm lambs, high-frequency oscillatory ventilation using simultaneous multiple oscillation frequencies improved gas exchange and lung recruitment at lower distending pressures; thus, future trials of high-frequency oscillatory ventilation might incorporate this approach. Background Despite the theoretical benefits of high-frequency oscillatory ventilation (HFOV) in preterm infants, systematic reviews of randomized clinical trials do not confirm improved outcomes. The authors hypothesized that oscillating a premature lung with multiple frequencies simultaneously would improve gas exchange compared with traditional single-frequency oscillatory ventilation (SFOV). The goal of this study was to develop a novel method for HFOV, termed “multifrequency oscillatory ventilation” (MFOV), which relies on a broadband flow waveform more suitable for the heterogeneous mechanics of the immature lung. Methods Thirteen intubated preterm lambs were randomly assigned to either SFOV or MFOV for 1 h, followed by crossover to the alternative regimen for 1 h. The SFOV waveform consisted of a pure sinusoidal flow at 5 Hz, whereas the customized MFOV waveform consisted of a 5-Hz fundamental with additional energy at 10 and 15 Hz. Per standardized protocol, mean pressure at airway opening ( JOURNAL/anet/04.03/00000542-201512000-00030/inline-graphic1/v/2024-12-02T212441Z/r/image-png ) and inspired oxygen fraction were adjusted as needed, and root mean square of the delivered oscillatory volume waveform (V rms) was adjusted at 15-min intervals. A ventilatory cost function for SFOV and MFOV was defined as JOURNAL/anet/04.03/00000542-201512000-00030/inline-graphic2/v/2024-12-02T212441Z/r/image-png , where Wt denotes body weight. Results Averaged over all time points, MFOV resulted in significantly lower V C (246.9 ± 6.0 vs. 363.5 ± 15.9 ml2 mmHg kg−1) and JOURNAL/anet/04.03/00000542-201512000-00030/inline-graphic3/v/2024-12-02T212441Z/r/image-png (12.8 ± 0.3 vs. 14.1 ± 0.5 cm H2O) compared with SFOV, suggesting more efficient gas exchange and enhanced lung recruitment at lower mean airway pressures. Conclusion Oscillation with simultaneous multiple frequencies may be a more efficient ventilator modality in premature lungs compared with traditional single-frequency HFOV.

Source: Anesthesiology

DOI: 10.1097/aln.0000000000000898