Stroke Volume Variation-Guided Goal-Directed Fluid Therapy Did Not Significantly Reduce the Incidence of Early Postoperative Complications in Elderly Patients Undergoing Minimally Invasive Esophagectomy: A Randomized Controlled Trial

Study Objective: This study aimed to investigate whether stroke volume variation (SVV)-guided goal-directed therapy (GDT) can improve postoperative outcomes in elderly patients undergoing minimally invasive esophagectomy (MIE) compared with conventional care.Design: A prospective, randomized, controlled study.Setting: A single tertiary care center with a study period from November 2017 to December 2018.Patients: Patients over 65 years old who were scheduled for elective MIE.Interventions: The GDT protocol included a baseline fluid supplement of 7 ml/kg/h Ringer's lactate solution and SVV optimization using colloid boluses assessed by pulse-contour analysis (PiCCO™). When SVV exceeded 11%, colloid was infused at a rate of 50 ml per minute; if SVV returned below 9% for at least 2 minutes, then colloid was stopped.Measurements: The primary outcome was the incidence of postoperative complications before discharge, as assessed using a predefined list, including postoperative anastomotic leakage, postoperative hoarseness, postoperative pulmonary complications, chylothorax, myocardial injury, and all-cause mortality.Main Results: Sixty-five patients were included in the analysis. The incidence of postoperative complications between groups was similar (GDT 36.4% vs. control 37.5%, P = 0.92). The total fluid volume was not significantly different between the two groups (2,192 ± 469 vs. 2,201 ± 337 ml, P = 0.92). Compared with those in the control group (n = 32), patients in the GDT group (n = 33) received more colloids intraoperatively (874 ± 369 vs. 270 ± 67 ml, P <0.05) and less crystalloid fluid (1,318 ± 386 vs. 1,937 ± 334 ml, P <0.05).Conclusion: The colloid-based SVV optimization during GDT did not significantly reduce the incidence of early postoperative complications after minimally invasive esophagectomy in elderly patients.Clinical Trial Number and Registry URL: ChiCTR-INR-17013352; http://www.chictr.org.cn/showproj.aspx?proj=22883

Stroke volume variation is a good predictor of fluid responsiveness in cardiac surgery patients with implanted intra-arortic balloon pump

There is a vast body of evidence in favor of individualising fluid therapy using dynamic hemodynamic indices like stroke volume variation (SVV). Patients with implanted intra-aortic balloon pump (IABP) are excluded from this approach because of pulse contour artifacts caused by the pump. The aim of this work is to test whether SVV can be used for fluid responsiveness prediction in these patients. Materials and methods: Patients after cardiac surgery with implanted IABP were included in this study. SVV was measured after placing the IABP on standy mode for one minute. Cardiac output (CO) measurement was obtained via Swan-Ganz catheter before and after a 6 ml/kg fluid challenge. Fluid responsiveness was defined as increase of CO by at least 10%. Results: SVV above 8.5% showed a good correlation with fuid responsiveness. Sensitivity was 95 (95% CI 85 to 100) and specificity 82 (95% CI 72 to 92). SVV had an area under the ROC curve 0.91 (95% CI 0.81 to 1.0) Conclusion: SVV is a good predictor of fluid responsiveness in patients with IABP. SVV should not be excluded as a fluid therapy guide for these patients. Placing the pump on standby for one minute allows obtaining an accurate measurement of this important variable.

The Effect of Intraoperative Fluid Management According to Stroke Volume Variation on Postoperative Bowel Function Recovery in Colorectal Cancer Surgery

Stroke volume variation (SVV) has been used to predict fluid responsiveness; however, it remains unclear whether goal-directed fluid therapy using SVV contributes to bowel function recovery in abdominal surgery. This prospective randomized controlled trial aimed to compare bowel movement recovery in patients undergoing colon resection surgery between groups using traditional or SVV-based methods for intravenous fluid management. We collected data between March 2015 and July 2017. Bowel function recovery was analyzed based on the gas-passing time, sips of water time, and soft diet (SD) time. Finally, we analyzed data from 60 patients. There was no significant between-group difference in the patients’ characteristics. Compared with the control group (n = 30), the SVV group (n = 30) had a significantly higher colloid volume and lower crystalloid volume. Moreover, the gas-passing time (77.8 vs. 85.3 h, p = 0.034) and SD time (67.6 vs. 85.1 h, p < 0.001) were significantly faster in the SVV group than in the control group. Compared with the control group, the SVV group showed significantly lower scores of pain on a numeric rating scale and morphine equivalent doses during post-anesthetic care, at 24 postoperative hours, and at 48 postoperative hours. Our findings suggested that, compared with the control group, the SVV group showed a faster postoperative SD time, reduced acute postoperative pain intensity, and lower rescue analgesics. Therefore, SVV-based optimal fluid management is expected to potentially contribute to postoperative bowel function recovery in patients undergoing colon resection surgery.

Collapsibility of caval vessels and right ventricular afterload: decoupling of stroke volume variation from preload during mechanical ventilation

Background: Collapsibility of caval vessels and stroke volume and pulse pressure variations (SVV, PPV) are used as indicators of volume responsiveness. Their behavior under increasing airway pressures and changing right ventricular afterload is incompletely understood. If the phenomena of SVV and PPV augmentation are manifestations of decreasing preload, they should be accompanied by decreasing transmural right atrial pressures. Methods: Eight healthy pigs equipped with ultrasonic flow probes on the pulmonary artery were exposed to positive end-expiratory pressure of 5 and 10 cmH2O and three volume states (Euvolemia, defined as SVV < 10%, Bleeding and Retransfusion). SVV and PPV were calculated for the right and PPV for the left side of the circulation at increasing inspiratory airway pressures (15, 20, 25 cmH2O). Right ventricular afterload was assessed by surrogate flow profile parameters. Transmural pressures in the right atrium and the inferior and superior caval vessels (IVC and SVC) were determined. Results: Increasing airway pressure led to increases in ultrasonic surrogate parameters of right ventricular afterload, increasing transmural pressures in the right atrium and SVC, and a drop in transmural IVC pressure. SVV and PPV increased with increasing airway pressure, despite the increase in right atrial transmural pressure. Right ventricular stroke volume variation correlated with indicators of right ventricular afterload. This behavior was observed in both PEEP levels and all volume states. Conclusions: Stroke volume variation may reflect changes in right ventricle afterload, rather than changes in preload.