title: Severe hypoxemia during veno-venous extracorporeal membrane oxygenation: exploring the limits of extracorporeal respiratory support.
abstract: OBJECTIVE
  Veno-venous extracorporeal oxygenation for respiratory support has emerged as a rescue alternative for patients with hypoxemia. However, in some patients with more severe lung injury, extracorporeal support fails to restore arterial oxygenation. Based on four clinical vignettes, the aims of this article were to describe the pathophysiology of this concerning problem and to discuss possibilities for hypoxemia resolution.
  
  
  METHODS
  Considering the main reasons and rationale for hypoxemia during veno-venous extracorporeal membrane oxygenation, some possible bedside solutions must be considered: 1) optimization of extracorporeal membrane oxygenation blood flow; 2) identification of recirculation and cannula repositioning if necessary; 3) optimization of residual lung function and consideration of blood transfusion; 4) diagnosis of oxygenator dysfunction and consideration of its replacement; and finally 5) optimization of the ratio of extracorporeal membrane oxygenation blood flow to cardiac output, based on the reduction of cardiac output.
  
  
  CONCLUSIONS
  Therefore, based on the pathophysiology of hypoxemia during veno-venous extracorporeal oxygenation support, we propose a stepwise approach to help guide specific interventions.
authors.affiliation: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, Emergency Department, Intensive Care Unit, São PauloSP, Brazil, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Emergency Department, Intensive Care Unit, São Paulo/SP, Brazil.
authors.forename: Liane Brescovici
authors.initials: LB
authors.lastname: Nunes
authors.affiliation: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, Emergency Department, Intensive Care Unit, São PauloSP, Brazil, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Emergency Department, Intensive Care Unit, São Paulo/SP, Brazil.
authors.forename: Pedro Vitale
authors.initials: PV
authors.lastname: Mendes
authors.affiliation: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, Emergency Department, Intensive Care Unit, São PauloSP, Brazil, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Emergency Department, Intensive Care Unit, São Paulo/SP, Brazil.
authors.forename: Adriana Sayuri
authors.initials: AS
authors.lastname: Hirota
authors.affiliation: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, Emergency Department, Intensive Care Unit, São PauloSP, Brazil, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Emergency Department, Intensive Care Unit, São Paulo/SP, Brazil.
authors.forename: Edzangela Vasconcelos
authors.initials: EV
authors.lastname: Barbosa
authors.affiliation: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, Emergency Department, Intensive Care Unit, São PauloSP, Brazil, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Emergency Department, Intensive Care Unit, São Paulo/SP, Brazil.
authors.forename: Alexandre Toledo
authors.initials: AT
authors.lastname: Maciel
authors.affiliation: Hospital Sírio Libanês, Intensive Care Unit, São PauloSP, Brazil, Hospital Sírio Libanês, Intensive Care Unit, São Paulo/SP, Brazil.
authors.forename: Guilherme Pinto Paula
authors.initials: GP
authors.lastname: Schettino
authors.affiliation: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, Respiratory Intensive Care Unit, São PauloSP, Brazil, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Respiratory Intensive Care Unit, São Paulo/SP, Brazil.
authors.forename: Eduardo Leite Vieira
authors.initials: EL
authors.lastname: Costa
authors.affiliation: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, Emergency Department, Intensive Care Unit, São PauloSP, Brazil, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Emergency Department, Intensive Care Unit, São Paulo/SP, Brazil.
authors.forename: Luciano Cesar Pontes
authors.initials: LC
authors.lastname: Azevedo
authors.affiliation: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, Emergency Department, Intensive Care Unit, São PauloSP, Brazil, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Emergency Department, Intensive Care Unit, São Paulo/SP, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Park
mesh_terms: D000293:Adolescent; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D015199:Extracorporeal Membrane Oxygenation / Q000379:methods*; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology* / Q000628:therapy; D055370:Lung Injury / Q000503:physiopathology; D008297:Male; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology; D010107:Oxygenators, Membrane; D015203:Reproducibility of Results; D012131:Respiratory Insufficiency / Q000628:therapy; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D010100:Oxygen