Low Blood Arterial Oxygenation During Venovenous Extracorporeal Membrane Oxygenation: Proposal for a Rational Algorithm-Based Management.
OBJECTIVE
Venovenous extracorporeal membrane oxygenation (VV-ECMO) is a therapeutic option in the management of the most severe forms of acute respiratory distress syndrome. Oxygenation during VV-ECMO depends on many parameters, and its management is complex. The management of ECMO is still not completely codified. The aim of this study was to rationalize the management of hypoxemia during VV-ECMO.


METHODS
To build a comprehensive flow diagram for management of hypoxemia during VV-ECMO, we considered (1) relationship between O2 arterial saturation and its determinants; (2) analysis of physiopathology of oxygenation under VV-ECMO; and (3) main guidelines and recommendations recapitulated in troubleshooting charts.


RESULTS
We propose a stepwise approach that could guide specific intervention to improve oxygenation during VV-ECMO. The first step is to obtain adequate pump flow, the main determinant of oxygenation, by eliminating a mechanical problem or inadequate venous drainage. Second, if hypoxemia persists, algorithm considers multiple reasons for inadequate oxygenation, namely: (1) excessive recirculation, (2) excessive cardiac output (decrease of ratio pump flow/cardiac output), (3) decrease in SvO2 (oxygen saturation in mixed venous blood), (4) malfunction of oxygenator, and (5) deterioration of residual lung function. Finally, for each modification of oxygenation parameters, specific measures are proposed to restore an adequate oxygenation by extracorporeal membrane oxygenation.


CONCLUSIONS
If hypoxemia occurs during VV-ECMO, collecting oxygenation parameters and a clear step-by-step algorithm could guide specific intervention to improve oxygenation. This flow diagram is in accordance with current recommendations recapitulated in guidelines or troubleshooting chart but more accurate and complete. Although rational and appealing, it remains to be tested together with a number of still unsolved issues.
Service de réanimation, Centre Hospitalier de Cholet, Cholet, France messaielmi@gmail.com.
Elmi
E
Messai
Département de Physique, Université de Souk Ahras, Souk Ahras, Algeria.
Abdesselam
A
Bouguerra
Department of Anesthesia and Critical Care Medicine, Azienda Ospedaliero Universitaria Pisana, Pisa, Italy.
Fabio
F
Guarracino
Cardiac Surgery, Experimental and Clinical Medicine Department, University of Florence, Firenze, Italy.
Massimo
M
Bonacchi
D000465:Algorithms; D002302:Cardiac Output; D015199:Extracorporeal Membrane Oxygenation / Q000009:adverse effects; D006801:Humans; D000860:Hypoxia / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D008168:Lung / Q000503:physiopathology; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D012128:Respiratory Distress Syndrome / Q000503:physiopathology / Q000628:therapy*
D010100:Oxygen
acute respiratory distress syndrome; extracorporeal membrane oxygenation; oxygenation; recirculation