Suprasternal ascending or descending aortic velocity peak variability assessment to predict fluid-responsiveness in healthy volunteers: the SADAVA-V pilot prospective study.

AIM

Evaluating fluid responsiveness (FR) is crucial in managing critically ill patients. Measurement of respiratory variations of blood flow (V) is physiologically sound, but blood flow sampling through the aortic valve (AV-V) is not always feasible. We assessed the feasibility of suprasternal V (SS-V), at ascending or descending aorta level, as alternative to AV-V.

METHODS

Observational prospective study in spontaneously breathing healthy volunteers. We report the overall feasibility of AV- and SS-V, and calculated their interchangeability, the mean bias with limits of agreement (LoA) and percentage error (PE). We defined FR as a 10% increase in cardiac output measured non-invasively with finger-cuff method after passive leg raising.

RESULTS

We enrolled 67 volunteers; SS-V was feasible in 65 volunteers (97%), with sampling in the ascending and descending aorta in 22/65 (33.8%) and 43/65 (66.2%) volunteers, respectively. AV-V was feasible in 64 volunteers (95.5%). When both V were obtained (n = 62), interchangeability using a 12% cut-off was 67.7% (poor agreement with kappa coefficient 0.19 [-0.02;0.41]). Clinical concordance at ascending aorta level was non-significantly higher (16/22, 73% vs 26/40, 65%; p = 0.583). Prediction of FR with SS-V using the 12% cut-off was poor: sensitivity 85%; specificity 9%; positive predictive value 82%; negative predictive value 11%. Bland-Altman's analysis revealed a mean bias -2.6% [-4.3%;-1.0%] with LoA ranging from -15.2% [- 18.1%;- 12.4%] to 10.0% [7.2%;12.8%]. The mean PE was 7.87%.

CONCLUSIONS

We report excellent feasibility for SS-V, though with moderate interchangeability and accuracy; however, we found poor precision and poor performances in predicting FR in healthy volunteers.