Extracorporeal life support for adults with acute respiratory distress syndrome

Abstract

Extracorporeal life support (ECLS) can support gas exchange in patients with the acute respiratory distress syndrome (ARDS). During ECLS, venous blood is drained from a central vein via a cannula, pumped through a semipermeable membrane that permits diffusion of oxygen and carbon dioxide, and returned via a cannula to a central vein. Two related forms of ECLS are used. Venovenous extracorporeal membrane oxygenation (ECMO), which uses high blood flow rates to both oxygenate the blood and remove carbon dioxide, may be considered in patients with severe ARDS whose oxygenation or ventilation cannot be maintained adequately with best practice conventional mechanical ventilation and adjunctive therapies, including prone positioning. Extracorporeal carbon dioxide removal (ECCO 2 R) uses lower blood flow rates through smaller cannulae and provides substantial CO 2 elimination (~ 20–70% of total CO 2 production), albeit with marginal improvement in oxygenation. The rationale for using ECCO 2 R in ARDS is to facilitate lung-protective ventilation by allowing a reduction of tidal volume, respiratory rate, plateau pressure, driving pressure and mechanical power delivered by the mechanical ventilator. This narrative review summarizes physiological concepts related to ECLS, as well as the rationale and evidence supporting ECMO and ECCO 2 R for the treatment of ARDS. It also reviews complications, limitations, and the ethical dilemmas that can arise in treating patients with ECLS. Finally, it discusses future key research questions and challenges for this technology.

COVID-19-associated acute respiratory distress syndrome (CARDS): Current knowledge on pathophysiology and ICU treatment – A narrative review

“…Veno-venous extracorporeal membrane oxygenation (vv-ECMO) is traditionally used to provide adequate tissue oxygenation and to reduce ventilator-induced (or patient self-inflicted) lung injury in select cases of severe ARDS [ 88 , 157 ]. While the impact of vv-ECMO on ARDS mortality has been documented but still partly discussed [ [158] , [159] , [160] , [161] ], a recent meta-analysis points toward the fact that the use of vv-ECMO lowers mortality and morbidity in selected critically ill patients [ 162 ].…”

“…A recent analysis showed a similar mortality of about 40% in ARDS patients with vv-ECMO than in CARDS patients with ECMO, which might imply that CARDS patients may benefit from vv-ECMO use similarly to ARDS patients [ 163 ]. However, current evidence for ECMO treatment in patients with CARDS remains scarce and ECMO use should thus likely be applied on an individual basis with respective ethical issues considered [ 157 ].…”

Ten golden rules for individualized mechanical ventilation in acute respiratory distress syndrome

“…Mechanical power (MP), the product of mechanical energy and respiratory rate, represents a measure of the amount of energy imparted to the patient by the mechanical ventilator. A related parameter, intensity, represents the normalization of MP to the lung surface area [ 5 , [6] , 7 , 8 , 9 , 10 , [11] , [12] , [13] , 14 , 15 , [16] , 17 , [18] , [19] , 20 , [21] , [22] , [23] , [24] , 25 , [26] , [27] , [28] , 29 , [30] , [31] , [32] , [33] , [34] , [35] , 36 , [37] , [38] , [39] , 40 , [41] , [42] , [43] , [44] , [45] , 46 , [47] , [48] , [49] , [50] , [51] , 52 , [53] , [54] , [55] , 56 , [57] , 58 , [59] , [60] , [61] , [62] , [63] , [64] , 65 , [66] , [67] , [68] , 69 , …”

“…Several randomized controlled trials (RCTs) and observational studies have investigated the role of lung-protective MV on ARDS outcome, thus revolutionizing conventional ventilatory management 7 , 8 , 9 , 10 , [11] . Moreover, the use of extracorporeal carbon dioxide removal (ECCO 2 R) [12] , extracorporeal membrane oxygenation (ECMO) [13] , inhaled vasodilators [14] , neuromuscular blocking agents (NMBAs) [15] , and prone positioning [16] , 17 have been discussed by multidisciplinary writing groups in recent guidelines as possible rescue strategies for more severe cases [18] , [19] .…”

ECMO Retrieval over the Mediterranean Sea: Extending Hospital Arms

“…Extracorporeal membrane oxygenation (ECMO) is a lifesaving treatment that provides mechanical cardiopulmonary support to critically-ill patients. Often utilized as a last resort in the critically-ill population, it has a progressively improved survival rate compared to that of previous treatments thanks to the technical refining of its materials, better knowledge of the applied management, and the identification of clearer indications considered earlier in the course of the critical disease [ 1 , 2 , 3 , 4 , 5 ]. As a lifesaving treatment, the number of centers practicing ECMO, with various case mixes and volumes, is increasing year by year.…”