title: Using very high frequencies with very low lung volumes during high-frequency oscillatory ventilation to protect the immature lung. A pilot study.
abstract: OBJECTIVE
  High-frequency oscillatory ventilation (HFOV) has been described as a rescue therapy in severe respiratory distress syndrome (RDS) with a potential protective effect in immature lungs. In recent times, HFOV combined with the use of volume guarantee (VG) strategy has demonstrated an independent effect of the frequency on tidal volume to increase carbon-dioxide (CO2) elimination. The aim of this study was to demonstrate the feasibility of using the lowest tidal volume on HFOV+VG to prevent lung damage, maintaining a constant CO2 elimination by increasing the frequency.
  
  
  METHODS
  Newborn infants with RDS on HFOV were prospectively included. After adequate and stable ventilation using a standard HFOV strategy, the tidal volume was fixed using VG and decreased while the frequency was increased to the highest possible to maintain a constant CO2 elimination. Pre- and post-PCO2, delta pressure and tidal volume obtained in each situation were compared.
  
  
  RESULTS
  Twenty-three newborn infants were included. It was possible to increase the frequency while decreasing the tidal volume in all patients, maintaining a similar CO2 elimination, with a tendency to a lower mean PCO2 after reaching the highest frequency. High-frequency tidal volume was significantly lower, 2.20 ml kg(-1) before vs 1.59 ml kg(-1) at the highest frequency.
  
  
  CONCLUSIONS
  It is possible to use lower delivered tidal volumes during HFOV combined with VG and higher frequencies with adequate ventilation to allow minimizing lung injury.
authors.affiliation: Neonatology Division, Instituto de Investigación Sanitaria Hospital General Universitario Gregorio Marañón, Complutense University of Madrid, Madrid, Spain.
authors.forename: N
authors.initials: N
authors.lastname: González-Pacheco
authors.affiliation: Neonatology Division, Instituto de Investigación Sanitaria Hospital General Universitario Gregorio Marañón, Complutense University of Madrid, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Sánchez-Luna
authors.affiliation: Neonatology Division, Instituto de Investigación Sanitaria Hospital General Universitario Gregorio Marañón, Complutense University of Madrid, Madrid, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Ramos-Navarro
authors.affiliation: Neonatology Division, Instituto de Investigación Sanitaria Hospital General Universitario Gregorio Marañón, Complutense University of Madrid, Madrid, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Navarro-Patiño
authors.affiliation: Neonatology Division, Instituto de Investigación Sanitaria Hospital General Universitario Gregorio Marañón, Complutense University of Madrid, Madrid, Spain.
authors.forename: A R-S
authors.initials: AR
authors.lastname: de la Blanca
mesh_terms: D001784:Blood Gas Analysis; D001997:Bronchopulmonary Dysplasia / Q000517:prevention & control*; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D006612:High-Frequency Ventilation / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008176:Lung Volume Measurements; D008297:Male; D010865:Pilot Projects; D011446:Prospective Studies; D012127:Respiratory Distress Syndrome, Newborn / Q000097:blood / Q000628:therapy*; D013990:Tidal Volume / Q000502:physiology*
chemical_list: D002245:Carbon Dioxide