Extracorporeal Membrane Oxygenation Blood Flow and Blood Recirculation Compromise Thermodilution-Based Measurements of Cardiac Output. Issue 5 (27th November 2021)

• Record Type: Journal Article
• Authors: Russ, Martin; Steiner, Elvira; Boemke, Willehad; Busch, Thilo; Melzer-Gartzke, Christoph; Taher, Mahdi; Badulak, Jenelle; Weber-Carstens, Steffen; Swenson, Erik R.; Francis, Roland C.E.; Pickerodt, Philipp A.
• Is Part Of: ASAIO journal. Volume 68:Issue 5(2022)
• Page Start: 721
• Page End: 729
• Publication Date: 2021-11-27
• Subjects: veno-venous -- extracorporeal membrane oxygenation -- recirculation fraction -- cardiac output measurements -- thermodilution -- acute lung injury; Artificial organs -- Periodicals; 617
• DOI: 10.1097/MAT.0000000000001592
• Languages: English
• ISSNs: 1058-2916

Abstract

Abstract : The contribution of veno-venous (VV) extracorporeal membrane oxygenation (ECMO) to systemic oxygen delivery is determined by the ratio of total extracorporeal blood flow (Q ˙ E C ) to cardiac output (Q ˙ ). Thermodilution-based measurements of Q ˙ may be compromised by blood recirculating through the ECMO (recirculation fraction; R f ). We measured the effects of Q ˙ E C and R f on classic thermodilution-based measurements of Q ˙ in six anesthetized pigs. An ultrasound flow probe measured total aortic blood flow (Q ˙ A 0 ) at the aortic root. R f was quantified with the ultrasound dilution technique. Q ˙ E C was set to 0–125% of Q ˙ A 0 and Q ˙ was measured using a pulmonary artery catheter (PAC) in healthy and lung injured animals. PAC overestimated Q ˙ (Q ˙ P a ) at all Q ˙ E C settings compared to Q ˙ A 0 . The mean bias between both methods was 2.1 L/min in healthy animals and 2.7 L/min after lung injury. The difference between Q ˙ P a and Q ˙ A 0 increased with an Q ˙ E C of 75–125%/Q ˙ A 0 compared to QEC <50%/Q ˙ A 0 . Overestimation of Q ˙ P a was highest when Q ˙ E C resulted in a high R f . Thus, thermodilution-based measurements can overestimate cardiac output during VV ECMO. The degree of overestimation of Q ˙ P a depends on the Q ˙ EC /Q ˙ A 0 ratio and the recirculation fraction.