Effect of lung protection strategy on stroke volume variation in patients undergoing open-chest operation

AbstractThe purpose of this study was to determine whether dynamic elastance EAdyn derived from echocardiographic measurements of stroke volume variations can predict the success of a one-step decrease of norepinephrine dose. In this prospective single-center study, 39 patients with vasoplegic syndrome treated with norepinephrine and for whom the attending physician had decided to decrease norepinephrine dose and monitored by thermodilution were analyzed. EAdyn is the ratio of pulse pressure variation to stroke volume variation and was calculated from echocardiography stroke volume variations and from transpulmonary thermodilution. Pulse pressure variation was obtained from invasive arterial monitoring. Responders were defined by a decrease in mean arterial pressure (MAP) > 10% following norepinephrine decrease. The median decrease in norepinephrine was of 0.04 [0.03–0.05] µg kg−1 min−1. Twelve patients (31%) were classified as pressure responders with a median decrease in MAP of 13% [12–15%]. EAdyn was lower in pressure responders (0.40 [0.24–0.57] vs 0.95 [0.77–1.09], p < 0.01). EAdyn was able to discriminate between pressure responders and non-responders with an area under the curve of 0.86 (CI95% [0.71 to1.0], p < 0.05). The optimal cut-off was 0.8. EAdyn calculated from the echocardiographic estimation of the stroke volume variation and the invasive arterial pulse pressure variation can be used to discriminate pressure response to norepinephrine weaning. Agreement between EAdyn calculated from echocardiography and thermodilution was poor. Echocardiographic EAdyn might be used at bedside to optimize hemodynamic treatment.

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Evaluation of Stroke Volume Variation Obtained by the FloTrac™/Vigileo™ System to Guide Preoperative Fluid Therapy in Patients Undergoing Brain Surgery

Journal of International Medical Research ◽

10.1177/147323001204000338 ◽

2012 ◽

Vol 40 (3) ◽

pp. 1175-1181 ◽

Cited By ~ 6

Author(s):

J Li ◽

Fh Ji ◽

Jp Yang

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Stroke Volume ◽

Stroke Volume Variation ◽

Brain Surgery ◽

Fluid Loading ◽

Volume Loading ◽

Fluid Infusion ◽

Volume Variation ◽

Ringer’S Lactate

OBJECTIVE: The accuracy of stroke volume variation (SVV) obtained by the FloTrac™/Vigileo™ system in otherwise healthy patients undergoing brain surgery was assessed. METHODS: Anaesthesia was induced in 48 patients with minimal fluid infusion. Before surgery, fluid volume loading was performed by infusion with Ringer's lactate solution in 200 ml steps over 3 min, repeated successively if the patient responded with an increase in stroke volume of ≥ 10%, until the increase was < 10% (nonresponsive). RESULTS: A total of 157 volume loading steps were performed in the 48 patients. Responsive and nonresponsive steps differed significantly in baseline values of blood pressure, heart rate and SVV. Significant correlations were found between the change in stroke volume after fluid loading and values of blood pressure, heart rate and SVV before fluid loading, with SVV the most sensitive variable. CONCLUSION: Stroke volume variation obtained using the FloTrac™/Vigileo™ system is a sensitive predictor of fluid responsiveness in healthy patients before brain surgery.

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