Intraoperative fluid optimization using stroke volume variation in high-risk surgical patients: preliminary results of a randomized prospective single-center study

Introduction

Stroke volume variation (SVV) is a good and easily obtained predictor of fluid responsiveness that can be used to guide fluid therapy in mechanically ventilated patients. During major abdominal surgery in patients with compromised cardiovascular reserves, inappropriate fluid management may result in occult organ hypoperfusion or in fluid overload and increased postoperative morbidity. The aim of our study was to evaluate the influence of SVV-guided fluid optimization on organ functions and postoperative morbidity and mortality in high-risk patients undergoing major abdominal surgery.

Methods

Patients undergoing elective intraabdominal vascular and nonvascular surgery were randomly assigned to a control group with routine intraoperative care and a SVV group with fluid management guided by SVV derived from the Vigileo/FloTrac system. The intervention target was to maintain the SVV index below 10% with colloid boluses of 3 ml/kg. Postoperative ICU care was the same for both groups. Demographic parameters, comorbidities, performed surgical procedures, mortality and ICU and hospital lengths of stay were assessed. Laboratory parameters of organ hypoperfusion in the perioperative period (pH, base excess, serum lactate) and number of infectious and organ complications on day 7 and day 30 after operation were evaluated. The Mann–Whitney, unpaired t test and chi-squared test were used accordingly; P < 0.05 was considered statistically significant. The study was approved by the local hospital ethic committee.

Results

A total of 80 patients were enrolled and randomized in the SVV (n = 40) and control (n = 40) groups. No significant differences between both groups in assessed parameters were found except for a difference in arterial pH (7.37 ± 0.05 vs. 7.35 ± 0.05; P = 0.04), lactate serum concentration at the end of the operation (median (IQR): 1.5 (1.2 to 1.9) mmol/l vs. 2.2 (1.39 to 2.35) mmol/l; P = 0.03) and the trend to lower rate of complications on day 30 in the SVV group (11 patients (39%) vs. 20 patients (57%); P = 0.06).

Conclusion

Fluid optimization guided by SVV during major abdominal surgery decreases blood lactate at the end of operation and may be associated with a trend for a lower rate of postoperative organ complications.