Comparison of Echocardiographic Indices Used to Predict Fluid Responsiveness in Ventilated Patients
Assessment of fluid responsiveness relies on dynamic echocardiographic parameters that have not yet been compared in large cohorts.Objectives:
To determine the diagnostic accuracy of dynamic parameters used to predict fluid responsiveness in ventilated patients with a circulatory failure of any cause.Methods:
In this multicenter prospective study, respiratory variations of superior vena cava diameter (ΔSVC) measured using transesophageal echocardiography, of inferior vena cava diameter (ΔIVC) measured using transthoracic echocardiography, of the maximal Doppler velocity in left ventricular outflow tract (ΔVmaxAo) measured using either approach, and pulse pressure variations (ΔPP) were recorded with the patient in the semirecumbent position. In each patient, a passive leg raise was performed and an increase of aortic velocity time integral greater than or equal to 10% defined fluid responsiveness.Measurements and Main Results:
Among 540 patients (379 men; age, 65 ± 13 yr; Simplified Acute Physiological Score II, 59 ± 18; Sequential Organ Failure Assessment, 10 ± 3), 229 exhibited fluid responsiveness (42%). ΔPP, ΔVmaxAo, ΔSVC, and ΔIVC could be measured in 78.5%, 78.0%, 99.6%, and 78.1% of cases, respectively. ΔSVC greater than or equal to 21%, ΔVmaxAo greater than or equal to 10%, and ΔIVC greater than or equal to 8% had a sensitivity of 61% (95% confidence interval, 57-66%), 79% (75-83%), and 55% (50-59%), respectively, and a specificity of 84% (81-87%), 64% (59-69%), and 70% (66-75%), respectively. The area under the receiver operating characteristic curve of ΔSVC was significantly greater than that of ΔIVC (P = 0.02) and ΔPP (P = 0.01).Conclusions:
ΔVmaxAo had the best sensitivity and ΔSVC the best specificity in predicting fluid responsiveness. ΔSVC had a greater diagnostic accuracy than ΔIVC and ΔPP, but its measurement requires transesophageal echocardiography.