Goal-Directed Intraoperative Fluid Management Using FloTrac© Monitoring in High-Risk Neurosurgical Patients

We hypothesize that the ability to assess volume status and fluid responsiveness with information gained from Edwards FloTrac/EV1000 system coupled with a goal-directed therapy fluid management algorithm can make a difference in patient outcomes. Our specific aims are:

* Demonstrate goal-directed therapy (GDT) in fluid management improves peri-operative fluid balance
* Demonstrate GDT improves pulmonary function and organ oxygenation
* Demonstrate GDT reduces necessary therapeutic interventions in the peri- operative period
* Demonstrate GDT reduces hypotensive episodes in the peri-operative period

Outcomes

We will study the consequences of goal-directed fluid therapy that employs use of dynamic indicators seen on FloTrac/EV1000 system by measuring the following:

* Pulmonary status

* Time to extubation
* Alveolar-arterial (A-a) gradient of oxygen
* Requirements for supplemental oxygen
* Organ oxygenation

* Serum lactate
* Arterial blood gas values (pH, HCO3, CO2, O2)
* Length of stay (LOS)

* In hospital, defined as time from operation start to eligibility for discharge from hospital according to surgeon in accordance with pre-define criteria
* In ICU/PACU, defined as time from operation end to eligibility for discharge from intensive care according to attending intensivist in accordance with pre- define criteria
* Fluid Balance

* Inputs and outputs (I/Os) of all measurable fluids (i.e. blood, crystalloid, colloid) in peri-operative period, through and including duration of intensive care or the next 24-48 hours after completion of surgery
* Drugs administered for fluid management (i.e. mannitol, vasopressors)
* Pre-operative and post-operative body weights and twice-daily weights via bed weights
* Hypotension

* Number, duration and severity (i.e. minimum blood pressure) of hypotensive episode, defined as MAP <65

• Phenylephrine (Drug), also known as Sudafed, Neo-Synephrine, SudoGest: if Mean arterial pressure (MAP) is < = 65, Stroke volume variation (SVV) < 13 and Cardiac Index is >=2.2 Phenylephrine is administered
• Epinephrine (Drug), also known as EpiPen, Adrenaclick, Medihaler-Epi: if Mean arterial pressure (MAP) is < = 65, Stroke volume variation (SVV) < 13 and Cardiac Index is < 2.2 Epinephrine is administered
• Albumin (Other): if Mean arterial pressure (MAP) is < = 65, Stroke volume variation (SVV) > = 13, fluids are administered --OR-- if Mean arterial pressure (MAP) is > 65, Stroke volume variation (SVV) > = 13 and Cardiac Index is <2.2 fluids are administered.
• Voluven (Other): if Mean arterial pressure (MAP) is < = 65, Stroke volume variation (SVV) > = 13, fluids are administered --OR-- if Mean arterial pressure (MAP) is > 65, Stroke volume variation (SVV) > = 13 and Cardiac Index is <2.2 fluids are administered.
• Normal Saline (Other): if Mean arterial pressure (MAP) is < = 65, Stroke volume variation (SVV) > = 13, fluids are administered --OR-- if Mean arterial pressure (MAP) is > 65, Stroke volume variation (SVV) > = 13 and Cardiac Index is <2.2 fluids are administered.
• Packed Red Blood Cells (Other): if Mean arterial pressure (MAP) is < = 65, Stroke volume variation (SVV) > = 13, fluids are administered --OR-- if Mean arterial pressure (MAP) is > 65, Stroke volume variation (SVV) > = 13 and Cardiac Index is <2.2 fluids are administered.
• FloTrac Monitor (Device): FloTrac monitor is connected for all patients, but only visible to the anesthesiologist for half. Based on a decision tree and the data from monitor, choices of interventions are used.

Primary outcomes

• Number of ICU Stays Greater Than 1.5 Days [20 Days]: the sum of ICU stays greater than the 1.5 Days eligibility for discharge from hospital according to the surgeon, over the course of 20 Days

Secondary outcomes

• Creatinine Change [Baseline and 72 hours]: Change in creatinine in the 72 hour post-op period (mg/dL)

Other outcomes

• Pulmonary Status as Measured by the Number of Participants Who Require Supplemental Oxygen [1 day]: We looked at the number of patients who required supplemental oxygen within the first 24 hours after surgery.
• Organ Oxygenation as Measured by Serum Lactate [Baseline and 24 Hours]: Serum lactate levels, as measured in mmol/L, in patients during the first 24 hours after surgery.
• Organ Oxygenation as Measured by Arterial Blood Gas Values [Baseline and 1 day]: Patient's organ oxygenation as measured by base deficit mEq/L, during the first 24 hours after surgery.
• Fluid Balance Measured by Inputs and Outputs (I/Os) of All Measurable Fluid in Peri-operative Period [Baseline and 12 Hours]: Fluid balance measured by I/Os of all fluid in the peri-op period during the first 12 hours after the subject's surgery.
• Patients Requiring Fluid Bolus for Management [1 day]: Number of patients who received fluid boluses in the first 24 hours post-op
• Number of Patients Treated for Hypotension With Phenylephrine Drip [1 day]: The number of patients on a phenylephrine drip within 24 hours post-op.
• Area Under Curve of MAP Below 65 [1 Day]: Hypotension as measured by area under the curve of MAP less than 65.

Sex: All, ages: 15 Years to any

Inclusion Criteria:

* Neurosurgical patients with concerns for decreased intracranial compliance;
* Orthopedic spine patients;
* Patients scheduled to undergo neurosurgical interventions that include any of the following will be eligible: intracranial aneurysm repair; or, major spine surgery.

Exclusion Criteria:

* Patients with permanent cardiac arrhythmias;
* Patients with severe aortic regurgitation;
* Patients with intra-aortic balloon pump (IABP);
* Patients undergoing emergency surgery; and,
* Women who are pregnant and/or nursing will be excluded.

Participant flow

Outcome results

• Number of ICU Stays Greater Than 1.5 Days (Primary), Number, Number of ICU Stays greater that 1.5 Day: Goal Directed Therapy 13 (7 to 19); Control Group 20 (14 to 26)
• Creatinine Change (Secondary), Mean, mg/dL: Goal Directed Therapy -0.04 +/- 0.25; Control Group -0.13 +/- 0.16
• Pulmonary Status as Measured by the Number of Participants Who Require Supplemental Oxygen (Other pre specified), Count of participants, Participants: Goal Directed Therapy 17; Control Group 25
• Organ Oxygenation as Measured by Serum Lactate (Other pre specified), Mean, mmol/L: Goal Directed Therapy 2.0 +/- 1.15; Control Group 1.75 +/- 1.04
• Organ Oxygenation as Measured by Arterial Blood Gas Values (Other pre specified), Mean, mEq/L: Goal Directed Therapy 3.55 +/- 3.96; Control Group 4.75 +/- 4.45
• Fluid Balance Measured by Inputs and Outputs (I/Os) of All Measurable Fluid in Peri-operative Period (Other pre specified), Mean, ml/kg: Goal Directed Therapy NA +/- NA; Control Group NA +/- NA
• Patients Requiring Fluid Bolus for Management (Other pre specified), Count of participants, Participants: Goal Directed Therapy 7; Control Group 6
• Number of Patients Treated for Hypotension With Phenylephrine Drip (Other pre specified), Count of participants, Participants: Goal Directed Therapy 0; Control Group 4
• Area Under Curve of MAP Below 65 (Other pre specified), Mean, mmHG x minutes: Goal Directed Therapy -65.06 +/- 63.89; Control Group -61.88 +/- 64.23

Adverse events

• Marc Bloom, MD, Principal investigator, New York University Medical School