Intraoperative hypotension and flap loss in free tissue transfer surgery of the head and neck

Background: In free flap head and neck reconstructions, hemodynamic management is complicated by the deleterious effects of excessive crystalloid administration. Patients may undergo periods of hypotension or excess fluid administration. The purpose of this study was to present our examination of the hypotheses that intraoperative hypotension and blood pressure lability are associated with increased fluid administration and flap failure. Methods: We reviewed the records of 445 patients undergoing head and neck surgery involving free tissue transfer. We used multivariate logistic regression to examine the relationship between hemodynamic variables and flap loss (primary outcome) and other complications. Results: On multivariate analysis, intraoperative hypotension and large-volume fluid administration were associated with flap loss. Neither blood pressure lability nor vasopressor administration was significantly associated to our primary outcome. Conclusions: Intraoperative hypotension is associated to flap failure in head and neck free tissue transfer surgeries, as is large-volume fluid administration.