"Awake" extracorporeal membrane oxygenation (ECMO): pathophysiology, technical considerations, and clinical pioneering.

Thomas Langer,Andriy I Batchinsky,Antonio Pesenti,Alessandro Santini,Nicola Bottino,Luciano Gattinoni,Stefania Crotti

doi:10.1186/s13054-016-1329-y

Abstract

Venovenous extracorporeal membrane oxygenation (vv-ECMO) has been classically employed as a rescue therapy for patients with respiratory failure not treatable with conventional mechanical ventilation alone. In recent years, however, the timing of ECMO initiation has been readdressed and ECMO is often started earlier in the time course of respiratory failure. Furthermore, some centers are starting to use ECMO as a first line of treatment, i.e., as an alternative to invasive mechanical ventilation in awake, non-intubated, spontaneously breathing patients with respiratory failure (“awake” ECMO). There is a strong rationale for this type of respiratory support as it avoids several side effects related to sedation, intubation, and mechanical ventilation. However, the complexity of the patient–ECMO interactions, the difficulties related to respiratory monitoring, and the management of an awake patient on extracorporeal support together pose a major challenge for the intensive care unit staff. Here, we review the use of vv-ECMO in awake, spontaneously breathing patients with respiratory failure, highlighting the pros and cons of this approach, analyzing the pathophysiology of patient–ECMO interactions, detailing some of the technical aspects, and summarizing the initial clinical experience gained over the past years.

Highlights

Venovenous extracorporeal membrane oxygenation (vv-ECMO) has been classically employed as a rescue therapy for patients with respiratory failure not treatable with conventional mechanical ventilation alone [1, 2]
It might be of interest to underline that, in the mechanically ventilated patient on ECMO, two lungs are contributing to respiration: the membrane lung, which is extremely efficient, and the native, failing lung, which can contribute only partially to gas exchange
“Successful weaning from IMV” defines the number of patients already intubated, mechanically ventilated, and on ECMO who were weaned from invasive mechanical ventilation, extubated, and managed with awake ECMO. *Patients of groups 1 and 2 and §patients of group 3 of the original publication by ARDS acute respiratory distress syndrome, COPD chronic obstructive pulmonary disease, ECCO2R extra-corporeal CO2 removal, IMV invasive mechanical ventilation, NA not available, PECLA pumpless extra-corporal lung assist; VV veno-venous need preoperative invasive respiratory support, apparently have a higher postoperative risk of death compared with patients not requiring preoperative invasive respiratory support [63]

Summary

Introduction

Venovenous extracorporeal membrane oxygenation (vv-ECMO) has been classically employed as a rescue therapy for patients with respiratory failure not treatable with conventional mechanical ventilation alone [1, 2]. If gas exchange needs are not met in other ways (e.g., through extracorporeal respiratory support), sedation, intubation, and mechanical ventilation could be necessary to avoid muscle exhaustion. 3. Emergent intubation and initiation of mechanical ventilation might become necessary in the awake, spontaneously breathing, non-intubated patient in cases of ECMO equipment failure.

Results

Conclusion