Goal Directed Fluid Therapy in Free Flap Patients

This study has been completed.
Sponsor:
Information provided by:
University of Manitoba
ClinicalTrials.gov Identifier:
NCT00869297
First received: March 24, 2009
Last updated: April 18, 2011
Last verified: April 2011
  Purpose

Fluid management of surgical patients has changed dramatically in recent years. Recent studies have shown that so called 'restrictive' fluid strategies can improve outcomes such as length of stay and time to fitness for discharge. Furthermore, new monitoring technologies have been developed that allow the clinician to better monitor the effects of intravenous fluid therapy.

The fluid management of free flap reconstruction surgery is controversial. As vasoactive agent use during the anesthetic is not the preferred intervention for the treatment of hypotension, fluid therapy is often administered to correct hemodynamic instability. A liberal fluid strategy may predispose the flap to edema, venous congestion and ultimately flap failure. A restrictive fluid strategy however has (at this institution) anecdotally been reported to lead to a higher incidence of deep venous thrombosis (DVT) and pulmonary embolus (PE). Thus, there is clinical equipoise as to the optimal fluid management for these patients.

Non-invasive cardiac output (CO) monitoring based on the arterial pulse contour is a nascent technological advance that has been widely validated in the operating theatre. The calculation of CO is based on the assumption that stroke volume is proportional to the integral of the area under the arterial pressure versus time curve. With these monitors, the variation in stroke volume during mechanical ventilation is also calculated and this can be utilized as an estimate of the patient's volume status. A stroke volume variation (SVV) of less than 15% has been shown to be indicative that a patient is no longer volume responsive.

In our study, we plan to recruit patients undergoing microvascular free flap reconstruction. Patients will be randomized to either standard care, or goal directed fluid therapy.

All patients will receive a pre-operative 5 ml kg-1 bolus of normal saline. Subsequently, all patients will then receive lactated ringers at a rate of 5 ml kg-1 hr-1. Patients in the intervention group will have their CO and SVV monitored by a Flo-Trac pulse contour monitor (Edwards Life Sciences, Irvine, CA). Patients in the intervention group will receive 6% tetrastarch boluses (Voluven, Fresenius Kabi, Hamburg, Germany) if their SVV exceeds 15%. Patients in the control arm will receive fluid at a rate and type at the discretion of the attending anesthesiologist to maintain hemodynamic stability and a urine output of 0.5 ml kg-1 hr-1.

Intra-operative variables studied will include total fluid administered (colloid and crystalloid), urine output, SVV and CO (both at the start and end of surgery). Postoperative variables examined will be urine output, daily fluid balance (days 0-3), incidence of DVT, PE, pulmonary edema, rate of re-operation, daily serum creatinine, chloride and bicarbonate concentration, and incidence of flap failure.

Measurements of flap oxygenation and water content will be made with near infrared spectroscopy at baseline, and during the immediate post-operative period (days 1-7).

We hypothesize that the goal directed group would have more intra-operative colloid given with a reduced incidence of adverse outcomes.


Condition Intervention
Free Flap Post Mastectomy
Other: Goal Directed Fluid Administration
Other: Control

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Single Blind
Primary Purpose: Treatment
Official Title: Goal Directed Fluid Therapy for Microvascular Free Flap Reconstruction Following Mastectomy: A Pilot Study

Resource links provided by NLM:


Further study details as provided by University of Manitoba:

Primary Outcome Measures:
  • Flap Oxygenation and Tissue Water [ Time Frame: 3 days ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:
  • Total IV fluid administered during the first 24 hours [ Time Frame: 24 hrs ] [ Designated as safety issue: Yes ]

Enrollment: 20
Study Start Date: March 2009
Study Completion Date: October 2010
Primary Completion Date: October 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Control Other: Control
Fluids titrated at discretion of anesthesiologist.
Experimental: Intervention
These patients receive fluid boluses based on measurements from the FloTrac
Other: Goal Directed Fluid Administration
Intravenous Fluid will be given if SVV exceeds 13%

  Eligibility

Ages Eligible for Study:   18 Years to 80 Years
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Female patients aged 18-80 undergoing primary microvascular free flap reconstruction after mastectomy.

Exclusion Criteria:

  • Weight >120kg Known or Suspected Aortic Insufficiency Renal Dysfunction (serum creatinine >150 μmol/l)
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00869297

Locations
Canada, Manitoba
University of Manitoba
Winnipeg, Manitoba, Canada, R3T4P6
Sponsors and Collaborators
University of Manitoba
  More Information

No publications provided

Responsible Party: Duane Funk, Assistant Professor of Medicine, Department of Anesthesia, University of Manitoba
ClinicalTrials.gov Identifier: NCT00869297     History of Changes
Other Study ID Numbers: B2008:135
Study First Received: March 24, 2009
Last Updated: April 18, 2011
Health Authority: Canada: Health Canada

ClinicalTrials.gov processed this record on September 15, 2014