Diastolic Function and Peripheral Venous Pressure as Indices for Fluid Responsiveness in Cardiac Surgical Patients

Abstract

Identifying fluid responsiveness is critical to optimizing perfusion while preventing fluid overload. An experimental study of hypovolemic shock resuscitation showed the importance of ventricular compliance and peripheral venous pressure (PVP) on fluid responsiveness. The authors tested the hypothesis that reduced ventricular compliance measured using transesophageal echocardiography results in decreased fluid responsiveness after a fluid bolus. Prospective observational study. Two-center, university hospital study. The study comprised 29 patients undergoing elective coronary revascularization. Albumin 5%, 7 mL/kg, was infused over 10 minutes to characterize fluid responders (>15% increase in stroke volume) from nonresponders. Invasive hemodynamics and the ratio of mitral inflow velocity (E-wave)/annular relaxation (e'), or E/e' ratio, were measured using transesophageal echocardiography to assess left ventricular (LV) compliance at baseline and after albumin infusion. Fifteen patients were classified as responders and 14 as nonresponders. The E/e' ratio in responders was 7.4 ± 1.9 at baseline and 7.1 ± 1.8 after bolus. In contrast, E/e' was significantly higher in nonresponders at baseline (10.7 ± 4.6; p = 0.04) and further increased after bolus (12.6 ± 5.5; p = 0.002). PVP was significantly greater in the nonresponders at baseline (14 ± 4 mmHg v 11 ± 3 mmHg; p = 0.02) and increased in both groups after albumin infusion. Fluid responsiveness was tested using the area under the receiver operating characteristic curve and was 0.74 for the E/e' ratio (95% confidence interval 0.55-0.93; p = 0.029) and 0.72 for the PVP (95% confidence interval 0.52-0.92; p = 0.058). Fluid responders had normal LV compliance and lower PVP at baseline. In contrast, nonresponders had reduced LV compliance, which worsened after fluid bolus. E/e,' more than PVP, may be a useful clinical index to predict fluid responsiveness.