title: Right over left ventricular end-diastolic area relevance to predict hemodynamic intolerance of high-frequency oscillatory ventilation in patients with severe ARDS.
abstract: BACKGROUND
  High-frequency oscillatory ventilation (HFOV) does not improve the prognosis of ARDS patients despite an improvement in oxygenation. This paradox may partly be explained by HFOV hemodynamic side-effects on right ventricular function. Our goal was to study the link between HFOV and hemodynamic effects and to test if the pre-HFOV right over left ventricular end-diastolic area (RVEDA/LVEDA) ratio, as a simple parameter of afterload-related RV dysfunction, could be used to predict HFOV hemodynamic intolerance in patients with severe ARDS.
  
  
  METHODS
  Twenty-four patients were studied just before and within 3 h of HFOV using transthoracic echocardiography and transpulmonary thermodilution.
  
  
  RESULTS
  Before HFOV, the mean PaO2/FiO2 ratio was 89 ± 23. The number of patients with a RVEDA/LVEDA ratio >0.6 significantly increased after HFOV [11 (46 %) vs. 17 (71 %)]. Although HFOV did not significantly decrease the arterial pressure (systolic, diastolic, mean and pulse pressure), it significantly decreased the cardiac index (CI) by 13 ± 18 % and significantly increased the RVEDA/LVEDA ratio by 14 ± 11 %. A significant correlation was observed between pre-HFOV RVEDA/LVEDA ratio and CI diminution after HFOV (r = 0.78; p < 0.0001). A RVEDA/LVEDA ratio superior to 0.6 resulted in a CI decrease >15 % during HFOV with a sensitivity of 80 % (95 % confidence interval 44-98 %) and a specificity of 79 % (confidence interval 49-95 %).
  
  
  CONCLUSIONS
  The RVEDA/LVEDA ratio measured just before HFOV predicts the hemodynamic intolerance of this technique in patients with severe ARDS. A high ratio under CMV raises questions about the use of HFOV in such patients.
  
  
  BACKGROUND
  ClinicalTrials.gov: NCT01167621.
authors.affiliation: Medical Surgical Intensive Care Unit, Saint Denis University Hospital, Saint Denis, Reunion Island, France. lursulet@gmail.com.
authors.forename: Lionel
authors.initials: L
authors.lastname: Ursulet
authors.affiliation: Medical Surgical Intensive Care Unit, Saint Denis University Hospital, Saint Denis, Reunion Island, France. roussiaux.mar@gmail.com.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Roussiaux
authors.affiliation: Medical Surgical Intensive Care Unit, Saint Denis University Hospital, Saint Denis, Reunion Island, France. dominique.belcour@chu-reunion.fr.
authors.forename: Dominique
authors.initials: D
authors.lastname: Belcour
authors.affiliation: Methodological Support and Biostatistics Unit, Saint Denis University Hospital, Saint Denis, Reunion Island, France. cyril.ferdynus@chu-reunion.fr.
authors.forename: Cyril
authors.initials: C
authors.lastname: Ferdynus
authors.affiliation: Medical Surgical Intensive Care Unit, Saint Denis University Hospital, Saint Denis, Reunion Island, France. bernard.gauzere@chu-reunion.fr.
authors.forename: Bernard-Alex
authors.initials: BA
authors.lastname: Gauzere
authors.affiliation: Medical Surgical Intensive Care Unit, Saint Denis University Hospital, Saint Denis, Reunion Island, France. david.vandroux@chu-reunion.fr.
authors.forename: David
authors.initials: D
authors.lastname: Vandroux
authors.affiliation: Medical Surgical Intensive Care Unit, Saint Denis University Hospital, Saint Denis, Reunion Island, France. jabot974@gmail.com.
authors.forename: Julien
authors.initials: J
authors.lastname: Jabot
keywords: Acute respiratory distress syndrome; Acute right ventricular dysfunction; Echocardiography; Hemodynamic monitoring; High-frequency oscillatory ventilation; Transpulmonary thermodilution