A comparison of pump-controlled retrograde trial off to arterio-venous bridging for weaning from venoarterial extracorporeal membrane oxygenation†

Abstract

OBJECTIVES The aim of the study is to compare a technique of pump-controlled retrograde trial off (PCRTO) to insertion of an arterio-venous (AV) bridge to conduct a trial from venoarterial extracorporeal membrane oxygenation (VA ECMO). METHODS We studied all patients who were weaned from VA ECMO using either PCRTO or AV bridging from November 2014 to April 2018. Demographic data, indications for ECMO, duration of ECMO, duration of trial period off ECMO and survival were compared between the 2 groups. RESULTS Seventy-nine patients were placed on VA ECMO from November 2014 to April 2018, of whom, 51 (65%) patients met the study inclusion criteria: 31 (61%) patients who had a trial period from VA ECMO using PCRTO and 20 (39%) patients who were weaned using an AV bridge. The indications for ECMO included cardiac (n = 16 and 11, respectively) and non-cardiac aetiologies (n = 15 and 9, respectively). There was 1 death in each group. The duration of the trial off VA ECMO was significantly shorter in the PCRTO group (median = 88.0 vs 196.6 min, P < 0.001). There were 2 conversions from PCRTO to AV bridging during the trial period off ECMO (2.9-kg neonate following a Norwood procedure and 2.2-kg patient following repair of ectopia cordis). CONCLUSIONS PCRTO is a safe, simple and reproducible approach for enabling a trial period while preserving the circuit during weaning from VA ECMO. In our study, the duration of the trial period off VA ECMO was significantly shorter in the PCRTO group. PCRTO avoids manipulation of the ECMO circuit, provides a ‘stress test’ to evaluate cardiorespiratory reserve during the trial period off ECMO, is applicable for a wide variety of cardiac and non-cardiac indications and facilitates multiple attempts at weaning from ECMO.

Pump-controlled retrograde trial off for weaning from adult veno-arterial extracorporeal membrane oxygenation – a retrospective observation cohort

“…Over the recent decades since the widespread utilization of V-A ECMO, multiple weaning strategies exist, of which decremental pump ow reduction and arteriovenous bridging recirculation technique are the mainstream approaches [2][3][4][5][6][7][8][9][10] . Nevertheless, variations in practice exist among institutions, and there are no consensus guidelines to standardize the weaning algorithms.…”

“…1). An APTT at 1.5-2.5 times the normal value had to be attained before initiation of PCRTO 9,10,12,13 , a bolus of unfractionated heparin would be given if the target clotting pro le is not met. The sweep gas ow to the oxygenator is turned off once the retrograde ECMO ow is achieved.…”

“…To the best of knowledge, decremental ow reduction and arteriovenous bridging recirculation remain the commonest adopted strategies to trial a patient off V-A ECMO [2][3][4][5][6][7][8][9][10] . Nevertheless, limitations of these strategies include variability in circuit arrangement between institutions, and risk of thromboembolic events during clamping of the circuit 11,12 .…”

Early experience of pump-controlled retrograde trial off for weaning from veno-arterial extracorporeal membrane oxygenation in adult patients with cardiogenic shock

“…They compared the results between the arteriovenous bridge group (n = 20) and the PCRTO group (n = 31), which expanded the study in 2019. 13 They reported that PCRTO is a safe, simple, and reproducible procedure while preserving the circuit in pediatric patients. In adult patients, there has been also an effort to check cardiovascular capacity under full cardiac loading before VA ECMO weaning.…”

Pump controlled retrograde trial off using the Cardiohelp console: safety considerations

“…Recently, several reports have been published on pump controlled retrograde trial off (PCRTO). [1][2][3][4][5][6] During PCRTO, the pump speed is reduced to the point where the patient can eject into the arterial cannula, effectively reversing the veno-arterial flow into an arteriovenous shunt. This leads to a temporary cessation of cardiorespiratory ECMO (extracorporeal membrane oxygenation) support without the need to clamp, introduce a 'bridge' or risk blood stasis in the circuit.…”