Comparative Analysis of the Collapsibility Index and Distensibility Index of the Inferior Vena Cava Through Echocardiography with Pulse Pressure Variation That Predicts Fluid Responsiveness in Surgical Patients: An Observational Controlled Trial.

OBJECTIVE

The objective for the present study was to compare the collapsibility (IcIVC) and distensibility (IdIVC) indices of the inferior vena cava with pulse pressure variation (PPV) and determine the accuracy and cutoff points of IcIVC and IdIVC that best predict response to intravenous fluid therapy in surgical patients.

DESIGN

Observational, prospective, nonblinded, single center.

SETTING

Hospital do Servidor Público Estadual de São Paulo, in São Paulo, Brazil.

PARTICIPANTS

Volunteer surgical patients.

INTERVENTIONS

This prospective study evaluated adult surgical patients before and after they underwent mechanical ventilation. IcIVC and IdIVC measurements were obtained with echocardiography and PPV through arterial catheterization.

MEASUREMENTS AND MAIN RESULTS

Twenty-two patients with a mean age of 55.7 ± 10.9 years were included; 31.8% of the study participants had PPV values >13% and were shown to be responsive to fluid. A good correlation was detected between PPV and icIVC (R = 0.71; p < 0.001) and between PPV and idIVC (R = 0.79; p < 0.001). The area under the receiver operating characteristic curve was 0.98 for icIVC (95% confidence interval 0.81-0.99; p < 0.001) and 0.88 for idIVC (95% confidence interval 0.67-0.98; p < 0.001).

CONCLUSIONS

PPV was found to have good correlation with the inferior vena cava diameter variation using echocardiography in surgical patients undergoing spontaneous and artificial ventilation. The cutoff values that best predicted PPV >13% were >40% for icIVC and >17.6% for idIVC.