Conditions: Intracranial Aneurysm Brain Edema Scoliosis Surgery
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 66
Healthy volunteers: no

Brief summary:
This is a prospective, randomized controlled trial to determine if using FloTrac/EV1000 system in neurosurgical patients undergoing craniotomies for aneurysm repair or tumor resection complicated by cerebral edema, or complex spinal surgery including multi-level scoliosis correction, is a more effective way of monitoring fluid.

Detailed description:
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

Arms:
arm 1: Flotrack monitor is connected and based on what anesthesiologist sees and following study algorithm, anesthesiologist chooses: Phenylephrine, Epinephrine , volume resuscitation (fluids, including normal saline, albumin, voluven and packed red blood cells) and no intervention. arm 2: FloTrac monitor is connected, but he anesthesiologist will not be able to see the monitor although the data will be collected and stored for analysis. Anesthesiologist will be given a study algorithm to follow for the duration of the surgery, and based on it will choose: Phenylephrine, Epinephrine , volume resuscitation (fluids, including normal saline, albumin, voluven and packed red blood cells) and no intervention.

Interventions: intervention 1: Phenylephrine intervention 2: Epinephrine intervention 3: Albumin intervention 4: Voluven intervention 5: Normal Saline intervention 6: Packed Red Blood Cells intervention 7: FloTrac Monitor
Intervention descriptions: intervention 1: if Mean arterial pressure (MAP) is \< = 65, Stroke volume variation (SVV) \< 13 and Cardiac Index is \>=2.2 Phenylephrine is administered intervention 2: if Mean arterial pressure (MAP) is \< = 65, Stroke volume variation (SVV) \< 13 and Cardiac Index is \< 2.2 Epinephrine is administered intervention 3: 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. intervention 4: 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. intervention 5: 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. intervention 6: 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. intervention 7: 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.

Protocol document: