The predictive ability of carotid artery corrected flow time and respirophasic variation in blood flow peak velocity measured by ultrasonography for fluid responsiveness in parturients for cesarean delivery.

BACKGROUND

Ultrasonic measurements of carotid artery corrected flow time (FTc) and respirophasic variation in blood flow peak velocity (ΔV<inf>peak</inf>) were recently introduced to predict fluid responsiveness in non-obstetric patients. We designed the present study to evaluate the performance of these two ultrasonic indices in predicting fluid responsiveness in healthy parturients.

METHODS

Seventy-five parturients undergoing elective cesarean delivery were enrolled. Carotid doppler parameters including FTc, ΔV<inf>peak</inf>, the inferior vena cava diameter at the end of expiration (IVC<inf>exp</inf>) and inspiration (IVC<inf>ins</inf>), Inferior Vena Cava Collapsibility Index (IVCCI), and Stroke Volume Index (SVI) were measured before and after fluid challenge. Fluid responsiveness was defined as a 15% or more increase in SVI as assessed by transthoracic echocardiography after the fluid challenge.

RESULTS

FTc and ΔV<inf>peak</inf> but not IVC<inf>ins</inf>, IVC<inf>exp</inf> and IVCCI were proved to be two independent predictors for fluid responsiveness by multivariate logistic regression, with the odds ratios of 1.191 (95% confidence interval (CI), 1.070 to 1.326) and 0.521 (95% CI, 0.351 to 0.773). The area under the ROC curve to predict fluid responsiveness for FTc was 0.846 (95% CI, 0.751-0.940) and for ΔV<inf>peak</inf> was 0.810 (95% CI, 0.709-0.910), which were significantly higher than those for IVC<inf>ins</inf> (0.436, 95% CI, 0.300-0.572), IVC<inf>exp</inf> (0.595, 95% CI, 0.460-0.730) and IVCCI (0.548, 95% CI, 0.408-0.688).

CONCLUSIONS

Compared with IVC<inf>ins</inf>, IVC<inf>exp</inf> and IVCCI, FTc and ΔV<inf>peak</inf> measured by ultrasonography seem to be the highly feasible and reliable methods to predict fluid responsiveness in parturients with spontaneous breathing undergoing elective cesarean delivery.