(246) An Evidence-Based Image Acquisition Protocol for Grading the Severity of RV Systolic Dysfunction

Introduction: A major risk factor for morbidity and mortality in critical illness is the presence of right ventricular (RV) systolic dysfunction. However, grading the severity of RV systolic dysfunction remains highly subjective, as current guidelines provide no guidance on differentiating mild, moderate, and severe RV dysfunction. This lack of guidance results in significant inter-operator and intra-operator variability, with potential for inappropriate treatment of patients.

Methods: We aimed to develop an evidence-based protocol for grading the severity of RV systolic dysfunction in the intensive care unit (ICU) using point-of-care ultrasound (POCUS). First, we conducted a scoping literature review to identify any existing validated RV dysfunction scoring systems. Second, we adapted the lone existing scoring system into an image acquisition protocol compatible with the constraints of cardiac POCUS in the ICU environment, where certain echocardiographic features are absent (EKG-gating and speckle-tracking strain) and patient factors frequently permit adequate visualization in only 1-2 sonographic windows (i.e., parasternal, apical, and/or subcostal).

Results: The resulting protocol assigns a point for each of the following: (1) RV dilation (RV/LV ratio > 2/3); (2) RV systolic dysfunction (tricuspid annular plane systolic excursion (TAPSE) < 17mm or RV S’ < 10 cm/sec); and (3) RV-pulmonary artery (PA) coupling (TAPSE/pulmonary artery systolic pressure ratio < 0.5). Further, we demonstrate how all three of these datapoints can be extracted from each individual sonographic window. The resulting image acquisition protocol is described step-wise and presented as an instructional video, including examples of representative results.

Conclusions: There exists a large unmet need to add objectivity to the grading of the severity of RV systolic dysfunction. To address this need, we have identified an already validated RV severity grading tool and adapted this tool for use with POCUS in the ICU. Finally, we review the theoretical and empirical basis for the scoring system and its limitations.