Identifying perioperative volume-related risk factors in head and neck surgeries with free flap reconstructions - An investigation with focus on the influence of red blood cell concentrates and noradrenaline use.

INTRODUCTION:The amount of fluids administered intraoperatively seems to influence the postoperative outcome, and especially the transfusion of red blood cell concentrates (RBC) are known to have an increased risk of postoperative complications. This prospective study focuses on patients planned with microvascular free flap reconstruction and investigates the effect of various types and amounts of volumes given intraoperatively and on the intensive care unit with regard to overall postoperative complications. MATERIAL AND METHODS:In this prospective study, 52 consecutive patients planned for reconstruction with microvascular free flaps were included. Intraoperatively administered volumes including blood products were documented by the anesthesiologists as well as volumes given during the intensive care unit stay. Postoperative complications were registered for the entire hospital stay. Statistical analysis was carried out correlating the amount and type of volumes with the incidence of postoperative complications. RESULTS:The intraoperative use of RBC showed a close to statistically significant increased risk of postoperative complications (mean/SD concentrates: 0.5/1.1 [no complications] vs. 1.0/1.4 [complications], p = 0.058). In a multivariate analysis with stepwise selection the use of human albumin, gelatin, or Ringer's acetate showed no correlation with complications. The overall blood loss, however, had no significant influence on the incidence of complications (mean/SD ml: 1187/761 [no complications] vs. 1004/600 [complications], p = 0.37). The use of noradrenalin during reconstructive surgeries with microvascular flaps bears statistically no increased risk of failure (mean/SD μg/kg/min: 36/23 [no flap loss] vs. 22/15 [flap loss], p = 0.289) or complications (mean/SD μg/kg/min: 34/22 [no complications] vs. 35/23 [complications], p = 0.807). CONCLUSION:In our investigation, the use of crystalloids and colloids seems to have no influence on the postoperative outcome, but the use of RBC may have an increased overall incidence of postoperative complications. A careful hemostasis to limit the use of RBC remains essential despite available options of substitutions. The use of infusion-pump-administered noradrenaline seems valuable to sustain a stable circulation during surgeries with microvascular free flaps and may have no negative impact on postoperative complications.