Subjective right ventricle assessment by echo qualified intensive care specialists: assessing agreement with objective measures.

BACKGROUND

Right ventricle (RV) size and function assessment by echocardiography (echo) is a standard tool in the ICU. Frequently subjective assessment is performed, and guidelines suggest its utility in adequately trained clinicians. We aimed to compare subjective (visual) assessment of RV size and function by ICU physicians, with advanced qualifications in echocardiography, vs objective measurements.

METHODS

ICU specialists with a qualification in advanced echocardiography reviewed 2D echo clips from critically ill patients on mechanical ventilation with PaO2:FiO2 < 300. Subjective assessments of RV size and function were made independently using a three-class categorical scale. Agreement (B-score) and bias (p value) were analysed using objective echo measurements. RV size assessment included RV end-diastolic area (EDA) and diameters. RV function assessment included fractional area change, S', TAPSE and RV free wall strain. Binary and ordinal analysis was performed.

RESULTS

Fifty-two clinicians reviewed 2D images from 80 patients. Fair agreement was seen with objective measures vs binary assessment of RV size (RV EDA 0.26 [p < 0.001], RV dimensions 0.29 [p = 0.06]) and function (RV free wall strain 0.27 [p < 0.001], TAPSE 0.27 [p < 0.001], S' 0.29 [p < 0.001], FAC 0.31 [p = 0.16]). However, ordinal data analysis showed poor agreement with RV dimensions (0.11 [p = 0.06]) and RV free wall strain (0.14 [p = 0.16]). If one-step disagreement was allowed, agreement was good (RV dimensions 0.6 [p = 0.06], RV free wall strain 0.6 [p = 0.16]). Significant overestimation of severity of abnormalities was seen with subjective assessment vs RV EDA, TAPSE, S' and fractional area change.

CONCLUSION

Subjective (visual) assessment of RV size and function, by ICU specialists trained in advanced echo, can be fairly reliable for the initial exclusion of significant RV pathology. It seems prudent to avoid subjective RV assessment in isolation.