Point-of-Care Ultrasound for Peripheral Veno-Arterial Extracorporeal Membrane Oxygenation Without Left Ventricular Venting

This manuscript outlines the use of cardiac point of care ultrasound or POCUS to monitor patients on peripheral VA-ECMO particularly in those without left ventricular venting. It explains how to screen for key pathologies during the maintenance phase of VA-ECMO, as well as incorporating cardiac POCUS into ECMO weaning. The use of cardiac POCUS in the context of VA-ECMO remains inconsistent due to the variability in provider training.

This study aims to address this knowledge gap by detailing POCUS image acquisition in VA-ECMO, particularly in the absence of LV venting. Because there are currently no guidelines detailing how to incorporate cardiac POCUS into VA-ECMO management, our manuscript offers a systematic evidence-based protocol to help clinicians integrate cardiac POCUS into the care of patients on peripheral VA-ECMO, especially in the absence of LV venting. To begin, place nitrile or latex-free gloves and sterile individually processed ultrasound jelly packets on the working platform.

Select a sector probe on the ultrasound machine. Then set the machine to the Cardiac preset. Ensure that the indicator appears on the right-hand side of the screen.

Place the patient in a supine position. Place blankets or ramps to position the patient in a slightly left-side-down trajectory. Using the phased array probe, obtain the parasternal long axis view of the heart and click on Acquire.

Assess the aortic valve for opening, then score aortic root thrombus as present, absent, or indeterminate. Activate the caliper tool to measure the left ventricular internal dimension during the R wave of the QRS tracing on the EKG. Click on Acquire to save the measurement.

Next, obtain an apical four-chamber view, and click on Acquire. Assess the left ventricular cavity for the presence of a thrombus, and score it as present, absent, or intermediate. To evaluate cardiac recovery and the feasibility of venoarterial extra corporeal membrane oxygenation, or VA-ECMO, assess whether there has been recovery from the underlying disease process that necessitated the initiation of VA-ECMO.

Perform echocardiographic evaluation during each ECMO wean. Start with obtaining the parasternal long axis view, and assess left ventricular systolic function qualitatively as either akinetic or showing some degree of function. Obtain the apical four-chamber view.

Qualitatively assess the right ventricle to left ventricle size ratio. Activate M mode to measure tricuspid valve annular plane systolic excursion. Perform active tissue Doppler imaging to measure the right ventricle S Prime and the lateral mitral annular S Prime.

Next, obtain the apical five-chamber view, and click Acquire to measure the left ventricular outflow tract velocity-time interval.