Stroke Volume Variation- Guided Hemodynamic Therapy Versus Oxygen Extraction Ratio-guided Hemodynamic Therapy

Stroke Volume Variation- Guided Hemodynamic Therapy Versus Oxygen Extraction Ratio-guided Hemodynamic Therapy

Stroke Volume Variation- Guided Hemodynamic Therapy Versus Oxygen Extraction Ratio-guided Hemodynamic Therapy on Outcomes Following Laparoscopic Gastrointestinal Cancer Surgery

The FloTrac/Vigileo is a minimal invasive device assessing flow based hemodynamic parameters by pulse contour analysis based on the radial artery pressure signal. This method gained popularity as it is minimally invasive compared to esophageal Doppler or pulmonary artery catheter insertion and provides continuous beat-to-beat data. The previous study with 110 patients found that that GDHT guided by stroke volume variation (SVV) using the FloTrac/Vigileo device was associated with a reduced length of hospital stay and a lower incidence of POGD in major abdominal oncological surgery. However, no difference was found in the incidence of postoperative complications between the two groups, lack of statistical power could be a limitation to demonstrate the true association. Therefore, further prospective trials are needed to address this issue. The use of early and efficient therapeutic strategies able to detect and to treat potential triggers of organ failures, such as tissue hypoperfusion, is particularly important. If hypoperfusion is not adequately managed, tissue hypoxia could occur, resulting from an impairment of the adaptive mechanisms of myocardial contractile function, under the influence of inflammatory mediators, and the peripheral tissues will then increase their oxygen extraction (O2ER). AS such, GDHT guided by O2ER may be appropriate to monitor GDHT strategies because it reflects the balance between oxygen delivery and consumption. Therefore, the investigators performed this single-center, randomized, controlled trial to investigate whether GDHT guided by SVV using FloTrac/Vigileo monitor and GDHT guided by O2ER would reduce incidence of postoperative complication and shorten the length of hospital stay, compared with a standard conventional fluid therapy in low-to-moderate risk patients undergoing major laparoscopic gastrointestinal oncological surgery.

stroke volume variation, oxygen extraction ratio, goal-directed fluid therapy, laparoscopic gastrointestinal surgery

SVV ≤12% and CI of at least 2.5 L•min-1•m-2 were required. 500 mL of crystalloids was infused during induction, followed by a 2 ml•kg-1•h-1continuous infusion. If SVV was higher than 12% for over 5 minutes, a 250 mL bolus of crystalloid was given. Another 250 ml bolus of colloid was administrated if SVV was still higher than 12% or SVV decreased over 10%. If CI value was below 2.5 L•min-1•m-2, inotropes were applied to reach this minimum CI, serving as a safety parameter to prevent patients from low cardiac output. If SVV and CI were within the target range but MAP was below 65 mmHg, norepinephrine was started. After the initial assessment, patients were reassessed every 5 minutes intraoperatively to maintain values according to the study algorithm

the goal of O2ER is assessed every one hour to keep O2ER<27% which calculated by the following equation:(SaO2 - SvO2)/SaO2, when O2ER is greated than 27%, CVP lower than 10mmHg, 250ml colloid is given, otherwise, inotropes is given as CVP≥10mmHg.

MAP was kept between 65 and 90 mmHg, CVP between 8 and 12 mmHg and urinary output more than 0.5 ml•kg-1•h-1. 500 ml of crystalloids was infused during induction, followed by a continuous infusion of crystalloids (4 ml•kg-1•h-1). If the MAP decreased below 65 mmHg, or if the CVP decreased below 8 mmHg, a 250 mL bolus of colloid was given after waiting 5 minutes if any one of the criteria was met. If the MAP decreased below 65 mmHg and remained unresponsive to fluids, norepinephrine or inotropes was given to maintain the MAP above 65 mmHg.

the number of patients with predefined moderate or major postoperative complications (pulmonary embolism, myocardial ischemia or infarction, arrhythmia, cardiac or respiratory arrest, limb or digital ischemia, cardiogenic pulmonary edema, acute respiratory distress syndrome, gastrointestinal bleeding, bowel infarction, anastomotic breakdown, paralytic ileus, acute psychosis, stroke, acute kidney injury, infection [source uncertain], urinary tract infection, surgical site infection, organ/space infection, bloodstream infection, nosocomial pneumonia, and postoperative hemorrhage

from the end of surgery until the date of discharge from hospital,assessed up to 30 days after surgery

from the end of surgery until the date of discharge from hospital,assessed up to 30 days after surgery

from the end of surgery until the date of discharge from hospital,assessed up to 30 days after surgery

Inclusion Criteria: 18~80 years ASA I~III Patients undergoing elective major laparoscopic gastrointestinal oncological surgery.Procedures were considered major if listed for resection cancer with tumor debulking, staging or reconstruction with a risk for significant surgical blood loss. Exclusion Criteria: co-existing congestive heart failure; chronic lung disease; or renal or hepatic dysfunction (creatinine >50 % or liver enzymes >50 % of normal values), and arrhythmias. less than 18 years pregnant or lactating woman patients undergoing emergency surgery