End-Tidal Carbon Dioxide Concentration Can Estimate the Appropriate Timing for Weaning Off From Extracorporeal Membrane Oxygenation for Refractory Circulatory Failure

Abstract

SummaryAlthough extracorporeal membrane oxygenation (ECMO) is widely used as temporary circulation support, there are no reports of direct parameters indicating cardiac recovery to determine the timing of weaning off.Twenty-five patients supported by ECMO due to hemodynamic deterioration were divided into 2 groups according to their outcome: weaned ECMO (W: n = 18) or not (NW: n = 7). In the W group, we examined the differences in parameters between the 2 time points, ECMO introduction, and the reduction in ECMO flow to 40% of the initial setting known as the conventional recovery point (C-point). Significant differences were observed in systolic pulmonary artery pressure, the cardiac index measured by the thermodilution method, C-reactive protein, lactate, base excess, and the end-tidal CO 2 concentration (ETCO 2 ). Next, by closely examining these 6 parameters measured every 12 hours, we found that only ETCO 2 had always changed steeply, like a 'flexion point' (E-point), in all W cases, but not in NW. The E-point was defined as an initial increase in ETCO 2 of ≥ 5 mmHg over the preceding 12 hours with a continued rise over the next 12 hours. E-points appeared as much as 95 ± 60 hours earlier than C-points and also preceded weaning off of ECMO.ETCO 2 can be a useful continuous parameter for predicting the adequate timing of weaning off of ECMO for circulatory failure at the bedside. (Int Heart J 2010; 51: 116-120) Key words: End-tidal carbon dioxide, Extracorporeal membrane oxygenation, Hemodynamic deterioration, Clinical predictor, Weaning E xtracorporeal membrane oxygenation (ECMO) is widely used not only for temporary cardiopulmonary support in cases of hemodynamic deterioration, but also in bridge therapy for left ventricular assist system (LVAS) as well as cardiac transplantation.1,2) Although setting up the equipment is easy, a quick overall methodology during management has not been fully established. There have been few guidelines concerning its utilization in relation to the treatment of fulminant myocarditis.3) The guidelines say, for example, that ECMO flow of 3-3.5 L/min initially should be reduced gradually with improved cardiac function to around 1.0 L/min, followed by weaning off. As for the predictive indicators, resultant ECMO flow fell to about 40% of the initial flow, implying cardiac recovery, and patients can subsequently be weaned off ECMO.3) Under conventional methodology using 'trial and error' as described above, however, there are no reports of direct parameters indicating cardiac recovery to determine the timing of weaning patients off ECMO. In this study, we focused on clinical variables measured continuously at the patient's bedside, especially the end-tidal carbon dioxide concentration (ETCO 2 ), to determine the appropriate time to wean patients off ECMO. MethodsPatient population and clinical classification: Thirty-seven consecutive patients with cardiovascular disorders treated with ECMO at our institution between 1996-2008 were investigated. We excluded patients in whom ECMO wa...

Usefulness of cardiac biomarkers to predict cardiac recovery in patients on extracorporeal membrane oxygenation support for refractory cardiogenic shock

“…Those studies were performed on patients receiving long-term circulatory support. Only 1 study evaluated the value of several markers for predicting ECMO weaning from 25 patients [21]. Those authors found that patients' BNP levels measured the day of ECMO implantation did not differ, regardless of whether or not they were subsequently weaned.…”

“…However, they observed that continuously measured end--tidal CO 2 concentration always changed abruptly, with a "flexion point" in all patients subsequently weaned but not in weaning failures. That flexion point was defined as an initial end-tidal CO 2 concentration increase of 5 mm Hg or greater, followed by a continuous rise over the next 12 hours; it preceded weaning off ECMO for all weaning successes [21].…”

Neonatal Cardiac ECMO in 2019 and Beyond

“…In adults, end-tidal CO 2 (etCO 2 ) has been shown to be a useful continuous parameter for predicting the adequate timing of weaning of ECMO for circulatory failure at the bedside (73). Many physicians dealing with neonates also use etCO 2 as it can indicate increasing pulmonary blood flow as a sign of increased intrinsic right ventricular output due to a healing myocardium or decreasing pulmonary vascular resistance.…”

S3 Guideline of Extracorporeal Circulation (ECLS/ECMO) for Cardiocirculatory Failure

“…(signifi kanter Anstieg des ETCO 2 zwischen ECLS-Implantation und im Rahmen des Weaning-Prozesses). 116 Im Gegensatz dazu scheinen Biomarker keinen zusätzlichen Nutzen bei der Entscheidung für oder gegen ein ECLS-Weaning bzw. eine ECLS-Implantation aufzuweisen.…”