Effect of the I/E ratio on CO^sub 2^ removal during high-frequency oscillatory ventilation with volume guarantee in a neonatal animal model of RDS

• Published in: European journal of pediatrics 2016-10, Vol.175 (10), p.1343
• Main Authors: Sánchez-luna, Manuel, González-pacheco, Noelia, Santos, Martín, Blanco, Ángel, Orden, Cristina, Belik, Jaques, Tendillo, Francisco J
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Hospitals; Lavage; Lung diseases; Neonatal care; Ratios; Respiratory distress syndrome; Ventilators
• ISSN: 0340-6199; 1432-1076
• DOI: 10.1007/s00431-016-2770-2

The objective of this study was to analyze the effect of I/E ratio on carbon dioxide (CO^sub 2^) elimination during high-frequency oscillatory ventilation (HFOV) combined with volume guarantee (VG). Five 2-day-old piglets were studied before and after a bronchoalveolar lavage (BAL). The effect of an I/E ratio of 1:1 and 1:2 with (VG-ON) and without VG (VG-OFF) on PaCO^sub 2^, as well as delta and mean airway pressures at the airway opening ([increment]Phf-ao, mPaw-ao) and at the tracheal level ([increment]Phf-t, mPaw-t) were evaluated at frequencies of 5, 8, 11, and 14 Hz. With the VG-ON, PaCO^sub 2^ was significant lower with the I/E ratio of 1:2 at 5 Hz compared with the 1:1. mPaw-t was higher than mPaw-ao, with 1:1 I/E ratio, and on VG-ON, this difference was statistically significant. Conclusion: "In this animal study and with this ventilator, the I/E ratio of 1:1 compared to 1:2 in HFOV and VG-ON did not produce a higher CO^sub 2^ lavage as when HFOV was used without the VG modality. Even more, a lower PaCO^sub 2^ was found when using the lower frequency and 1:2 ratio compared to 1:1. So in contrast to non-VG HFOV mode, using a fixed tidal volume, no significant changes on CO^sub 2^ elimination are observed during HFOV when the I/E ratios of 1:1 and 1:2 are compared at different frequencies." [Table omitted.]