Chapter 8 use of colloid did not affect the total intravenous fluid volume used. Flap‐related complications such as TFL/PFL/FN were not affected by the volume of fluid therapy. In 14 patients, vasoactive medication (ephedrine) was used in a variable dosage 5–40 mg IV to maintain adequate perfusion pressure. The use of ephedrine was associated (not significant) with a lower intravenous fluid therapy volume, and its use was not related to any complications. Anastomosis revision was significantly increased in case of high fluid therapy. Free tissue transfer is complex, and success is dependent on various factors. The aim of anesthesia is to maintain intravascular fluid volume for optimal tissue perfusion and oxygenation, which includes the free flap. There are many factors that influence flap perfusion. Decreased tissue perfusion can be caused by hypothermia, hypovolemia, catecholamine response to pain, surgical manipulation of the pedicle, anesthetic‐ induced decrease of myocardial contractility, reduced cardiac output, and hypotension. General anesthesia induces hypotension, especially during induction. Anesthesiologists treat hypotension by decreasing the amount of anesthetic, by increasing intravascular volume, and by administering systemic vasopressors. There is debate regarding which vasoactive medications are safe in microsurgical reconstructive surgery, and microsurgeons are reluctant to the use of vasopressors because of possible pedicle and/or acceptor vessel vasospasm. Anesthesia‐induced hypotension can be treated by optimizing intravascular fluid volume. However, fluid overload should be avoided, because it has deleterious effects on anastomosis patency. It has been found that aggressive fluid therapy is a predictor of medical and surgical complications in head and neck free flap reconstruction.2 This finding was confirmed by Clark et al., who demonstrated that high crystalloid volume was associated with increased patient morbidity in head and neck patients.3 Excessive fluid administration was also associated with increased flap revision and failure rate in head and neck patients and is confirmed in our study.4 Compared with head and neck patients, breast reconstruction patients are in relative good health, and our study was the first to report that excessive fluid therapy increases the anastomosis revision rate. Our findings have been supported by a recent publication by Zhong et al., which demonstrated that a high crystalloid infusion rate is a predictor of flap‐related complications.5 The anesthetic technique used also has an effect on hypotension. Total intravenous anesthesia has a greater decrease in arterial pressure compared with inhalation anesthesia.6 After completing the anastomosis in free flap breast reconstruction, patients are placed in a Fowler position to facilitate the closure of the donor site and the shaping of the reconstructed breast. This patient position change has been shown to decrease hemodynamic function. These changes were greater with total intravenous anesthesia compared with inhalation anesthesia.7 The impact of vasoactive medication in reconstructive microsurgery is a subject of debate. In our study, vasoactive medication (mainly ephedrine) was not associated with 114
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