key: cord-0016821-ma9lybsn
authors: Pettenuzzo, Tommaso; Pichette, Maxime; Douflé, Ghislaine; Fan, Eddy
title: Effect of Ultraprotective Mechanical Ventilation on Right Ventricular Function During Extracorporeal Membrane Oxygenation in Adults With Acute Respiratory Distress Syndrome
date: 2020-11-05
journal: J Cardiothorac Vasc Anesth
DOI: 10.1053/j.jvca.2020.11.001
sha: 4e39d6e1dafe4b749b735992251958e63effaca5
doc_id: 16821
cord_uid: ma9lybsn

nan

To the Editor:

Right ventricular dysfunction (RVD) and acute cor pulmonale are frequent in patients with acute respiratory distress syndrome (ARDS) and may be associated with mortality. 1 Venovenous extracorporeal membrane oxygenation (V-V ECMO) may allow the use of ultraprotective mechanical ventilation in the most severe cases of ARDS. 2 However, the effects of this mechanical ventilation strategy on right ventricle (RV) function are not well known. Indeed, alveolar collapse, increased pulmonary vascular resistance, and RVD may occur with these settings. 3 We conducted a retrospective observational study to assess the prevalence and evolution of RVD with echocardiography in patients supported with V-V ECMO for severe ARDS and ventilated with an ultraprotective ventilation strategy, including a driving pressure of 10 cmH 2 O. This study was approved by the Research Ethics Board of the University Health Network, Toronto, Canada, and performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.

Of the 153 patients who received V-V ECMO for severe ARDS between January 2014 and December 2017 at our institution, we included 18 patients (median age 43 years, eight women) who were assessed with echocardiography before and after cannulation. Before cannulation, RV dilatation was present in six of 16 (37%) and 10 of 17 (59%) patients, according to quantitative and qualitative assessment, respectively, and RVD was reported in nine of 14 (64%) patients, according to either measurement of RV systolic function (Table 1) . Immediately after cannulation, tidal volume, plateau pressure, and driving pressure significantly decreased. RV size and systolic function were not significantly different after ECMO initiation, and the estimated right ventricular systolic pressure significantly decreased (Table 1) . ECMO sweep gas flow showed an inverse correlation with right ventricular systolic pressure, and the arterial partial pressure of oxygen was correlated directly with RV fractional area change ( Table 2 ). Although arterial oxygen saturation before cannulation was significantly lower in nonsurvivors, no other independent risk factor for RVD, RV dilatation, or mortality was identified in our population (data not reported).

This study had several limitations. It was a single-center, retrospective, observational study, with a small sample size; most patients were excluded because of missing echocardiograms or echocardiographic parameters. Moreover, considering that the echocardiograms were requested for clinical purposes rather than as part of a standardized serial protocol, we cannot exclude a selection bias for more severely ill patients and that patients' variable hemodynamic and respiratory conditions affected our findings.

In conclusion, RVD and dilatation were frequent before ECMO cannulation but were not associated with mortality. The extremely low tidal volumes during ECMO support did not cause a worsening of RV size and function or an increase of right ventricular systolic pressure, which was correlated inversely to the ECMO sweep gas flow. Prospective studies, including serial echocardiographic monitoring of RV function during V-V ECMO, are needed to assess the effect of lung rest ventilation on RV function and to clarify whether RVD in ARDS is a marker of a more severe underlying disease or an independent risk factor for mortality. Crs, static respiratory system compliance; DP, driving pressure; F I O 2 , fraction of inspired oxygen; LVEF, left ventricular ejection fraction; n.a., not applicable due to difficulty in determining the capillary oxygen content without precise estimations of patient's cardiac output; PaCO 2 , arterial partial pressure of carbon dioxide; PaO 2 , arterial partial pressure of oxygen; PBW, predicted body weight; PEEP, positive end-expiratory pressure; Pplat, plateau pressure; RV, right ventricle; RVD, RV dysfunction; RVFAC, fractional area change of the RV; RV S', pulsed Doppler S wave of the RV; RVSP, RV systolic pressure; SaO 2 , arterial oxygen saturation; TAPSE, tricuspid annular plane systolic excursion; V-V ECMO, venovenous extracorporeal membrane oxygenation. * Data available for 9 of 18 patients before cannulation and 17 of 18 patients after cannulation. y Defined as 24-hour fluid balance for the midnight before the echocardiographic exam. Data available for 6 of 18 patients before cannulation and 13 of 18 patients after cannulation. z RV dilatation is defined as RV basal diameter > 4.1 cm (Lang et al. 4 ). Data available for 16 of 18 patients before cannulation and 9/18 patients after cannulation. x Data available for 14 of 18 patients before cannulation and 12 of 18 patients after cannulation. jj Data available for 11 of 18 patients before cannulation and 11 of 18 patients after cannulation. { Data available for 6 of 18 patients before cannulation and 4 of 18 patients after cannulation. ** Defined as TAPSE < 17 mm, RV S' < 9.5 cm/s, or RVFAC < 35% (Lang et al. 4 ). Data available for 14/18 patients before cannulation and 12/18 patients after cannulation. yy RVSP was determined from peak tricuspid regurgitation jet velocity and an estimate of the right atrial pressure (Rudski et al. 5 ). Data available for 11 of 18 patients before cannulation and 10/18 patients after cannulation. zz Data available for 13 of 18 patients before cannulation and 13 of 18 patients after cannulation.

Letters to the Editor / Journal of Cardiothoracic and Vascular Anesthesia 35 (2021) 1897À1909

Dr. Fan is supported by a New Investigator Award from the Canadian Institutes of Health Research. Dr. Fan reports personal fees from ALung Technologies, Abbott, Fresenius, and MC3 Cardiopulmonary outside the submitted work. All other authors state that they have no conflicts of interest. This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. ECMO, extracorporeal membrane oxygenation; PaCO 2, arterial partial pressure of carbon dioxide; PaO 2, arterial partial pressure of oxygen; RV, right ventricle; RVFAC, fractional area change of the RV; RV S', pulsed Doppler S wave of the RV; RVSP, RV systolic pressure; TAPSE, tricuspid annular plane systolic excursion. * Data available for 16 of 18 patients before cannulation and 9 of 18 patients after cannulation. y Data available for 14 of 18 patients before cannulation and 12 of 18 patients after cannulation. z Data available for 11 of 18 patients before cannulation and 11 of 18 patients after cannulation.

x Data available for 6 of 18 patients before cannulation and 4 of 18 patients after cannulation. jj Data available for 11 of 18 patients before cannulation and 10 of 18 patients after cannulation.

Right ventricular dysfunction during acute respiratory distress syndrome and veno-venous extracorporeal membrane oxygenation

Mechanical ventilation management during extracorporeal membrane oxygenation for acute respiratory distress syndrome. An international multicenter prospective cohort

The right ventricle in ARDS

Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the

American Society of Echocardiography and the European Association of Cardiovascular Imaging

Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography