A Mukerji1, J Belik1, M Sanchez-Luna2. 1. Division of Neonatology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, ON, Canada. 2. Division of Neonatology, Instituto de Investigación Sanitaria Gregorio Marañón, Hospital General Universitario "Gregorio Marañón", University Complutense of Madrid, Madrid, Spain.
Abstract
OBJECTIVE: To examine the role of frequency in high-frequency ventilation (HFV) on carbon-dioxide (CO2) elimination and lung injury, independent of its effect on tidal volume. STUDY DESIGN: An anatomically representative lung model was attached to a mechanical ventilator capable of providing HFV with a constant volume. CO2 was infused directly into the lung, and a commercially available end-tidal CO2 detector was used to determine CO2 elimination. CO2 elimination and amplitude of pressure transmissions were evaluated using frequencies ranging from 5 to 15 Hz. The pressure-volume index (PVI) was described as the product of the volume and pressures delivered to the lung, a surrogate for lung injury. RESULT: The use of increasing frequencies directly correlated with improved CO2 clearance when keeping the tidal volume fixed, expressed as percent CO2 remaining in the lung at 25 s (66.5 (±1.1)%, 50.5 (±0.1)% and 37.8 (±0.3)% at 5, 10 and 15 Hz, respectively, P<0.05). With a fixed tidal volume, there was a decrease in pressure amplitudes transmitted to the lung with a decline in the PVI (53.9 (±2.7) mmHg ml(-1), 41.1 (±0.9) mmHg ml(-1) and 23.4 (±3.6) mmHg ml(-1), at 5, 10 and 15 Hz, respectively, P<0.05). CONCLUSION: Frequency has a direct relationship with CO2 elimination when tidal volume is fixed. Using low delivered tidal volumes and high frequencies may allow for improved ventilation efficacy, while minimizing lung injury.
OBJECTIVE: To examine the role of frequency in high-frequency ventilation (HFV) on carbon-dioxide (CO2) elimination and lung injury, independent of its effect on tidal volume. STUDY DESIGN: An anatomically representative lung model was attached to a mechanical ventilator capable of providing HFV with a constant volume. CO2 was infused directly into the lung, and a commercially available end-tidal CO2 detector was used to determine CO2 elimination. CO2 elimination and amplitude of pressure transmissions were evaluated using frequencies ranging from 5 to 15 Hz. The pressure-volume index (PVI) was described as the product of the volume and pressures delivered to the lung, a surrogate for lung injury. RESULT: The use of increasing frequencies directly correlated with improved CO2 clearance when keeping the tidal volume fixed, expressed as percent CO2 remaining in the lung at 25 s (66.5 (±1.1)%, 50.5 (±0.1)% and 37.8 (±0.3)% at 5, 10 and 15 Hz, respectively, P<0.05). With a fixed tidal volume, there was a decrease in pressure amplitudes transmitted to the lung with a decline in the PVI (53.9 (±2.7) mmHg ml(-1), 41.1 (±0.9) mmHg ml(-1) and 23.4 (±3.6) mmHg ml(-1), at 5, 10 and 15 Hz, respectively, P<0.05). CONCLUSION: Frequency has a direct relationship with CO2 elimination when tidal volume is fixed. Using low delivered tidal volumes and high frequencies may allow for improved ventilation efficacy, while minimizing lung injury.
Authors: Sherry E Courtney; David J Durand; Jeanette M Asselin; Mark L Hudak; Judy L Aschner; Craig T Shoemaker Journal: N Engl J Med Date: 2002-08-29 Impact factor: 91.245
Authors: N González-Pacheco; M Sánchez-Luna; C Ramos-Navarro; N Navarro-Patiño; A R-S de la Blanca Journal: J Perinatol Date: 2016-01-07 Impact factor: 2.521