Abstract

Traditionally, vasopressors are avoided in microvascular surgery. This tradition is largely based on animal studies, which demonstrated that ephedrine and phenylephrine may lead to decreased graft perfusion and pedicle thrombosis. Modern clinical evidence is largely unable to replicate these results, as no consistent correlation is observed between flap compromise and vasopressor use. Although some isolated studies show potential flap compromise with vasopressor exposure, the vast majority of modern clinical evidence suggests that vasopressor exposure poses no increased risk to flap compromise.

Liberal fluid administration is the traditional approach to hemodynamic management during microvascular surgery, however, modern clinical evidence suggests that high fluid volume increases the risk of free-flap complications. Significant risks of volume overload include cardiopulmonary compromise, poor wound healing, dehiscence, infection, and increased interstitial edema which may result in poor anastomosis and ultimately flap failure. In fact, fluid volume overload has been found to increase reoperation rates by up to 400% in some notable studies. Even in analyses that control for vasopressor use, total fluid volume remains a consistent independent risk factor for major free-flap complications. To minimize the risk of fluid volume overload, evidence-based fluid guidelines include low-volume, goal-directed fluid therapy, in alignment with Enhanced Recovery After Surgery (ERAS) protocols. For free-flap surgeries, most clinical evidence suggests <5 L total fluid volume administration, as > 7 L total perioperative fluid volume is associated with significantly increased flap complications.

Author Details

Merry K Otte, DNP(c), BSN, RN since 2020, which includes 3 years of cardiothoracic ICU experience. Current SRNA; Lauren Barnes, DNP, CRNA

Sigma Membership

Non-member

Type

DNP Capstone Project

Format Type

Text-based Document

Study Design/Type

Case Study/Series

Research Approach

Translational Research/Evidence-based Practice

Keywords:

Free Flaps, Maxillofacial Surgery, Perioperative Care, Vasoconstrictors, Vasopressors, Fluid Volume, Fluid Therapy

Advisor

Terri M. Cahoon

Degree

DNP

Degree Grantor

Samford University

Degree Year

2026

Rights Holder

All rights reserved by the author(s) and/or publisher(s) listed in this item record unless relinquished in whole or part by a rights notation or a Creative Commons License present in this item record. All permission requests should be directed accordingly and not to the Sigma Repository. All submitting authors or publishers have affirmed that when using material in their work where they do not own copyright, they have obtained permission of the copyright holder prior to submission and the rights holder has been acknowledged as necessary.

Review Type

None: Degree-based Submission

Acquisition

Proxy-submission

Date of Issue

2026-03-18

Full Text of Presentation

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Additional Files

Abstract.pdf (119 kB)

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