Evaluating the Utility of Portal Vein Pulsatility Index for Detecting Fluid Unresponsiveness in the Intensive Care Unit

Abstract

The primary aim of the authors' study was to evaluate the capacity of the portal vein pulsatility index (PVP) to detect fluid unresponsiveness in patients admitted to intensive care. This was a retrospective, diagnostic accuracy study SETTING: At a tertiary medical-surgical intensive care unit in Buenos Aires, Argentina. Patients were included during usual care in the intensive care unit, who were evaluated by ultrasonography for the flow of the portal vein, calculating their PVP prior to fluid expansion. Patients who exhibited an increase of <15% in left ventricle outflow tract velocity-time integral after receiving 500 mL of Ringer Lactate were considered non-responders to fluids. The authors included a total of 63 patients between January 2022 and October 2022. The area under the receiver operating characteristic curve for PVP to predict fluid unresponsiveness was 0.708 (95% CI 0.580 to 0.816). A value of the PVP >32% predicted fluid unresponsiveness with a sensitivity of 30.8% (95% CI 17% to 47.6%) and specificity of 100% (95% CI 85.8 to 100). The positive predictive value was 100%, and the negative predictive value was 47.1% (95% CI 41.9% to 52.3%). Although PVP has limited value as the sole indicator for fluid management decisions, it can be used as a stopping rule or combined with other diagnostic tests to improve the accuracy of fluid responsiveness assessment.