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.

Influence of Different Methods of Intrapartum Analgesia on the Progress of Labour and on Perinatal Outcome.

Background Various methods of intrapartum analgesia are available these days. Pethidine, meptazinol and epidural analgesia are among the most commonly used techniques. A relatively new one is patient-controlled intravenous analgesia with remifentanil, although the experiences published so far in Germany are limited. Our goal was to study the influence of these analgesic techniques (opioids vs. patient-controlled intravenous analgesia with remifentanil vs. epidural analgesia) on the second stage of labour and on perinatal outcome. Material and Methods We conducted a retrospective study with 254 parturients. The women were divided into 4 groups based on the analgesic technique and matched for parity, maternal age and gestational age (opioids n = 64, patient-controlled intravenous analgesia with remifentanil n = 60, epidural analgesia n = 64, controls without the medicinal products mentioned n = 66). Maternal, fetal and neonatal data were analysed. Results The expulsive stage was prolonged among both primiparas and multiparas with patient-controlled intravenous analgesia with remifentanil (79 [74] vs. 44 [55] min, p = 0.016, and 28 [68] vs. 10 [11] min, p < 0.001, respectively) and epidural analgesia (90 [92] vs. 44 [55] min, p = 0.004, and 22.5 [73] vs. 10 [11] min, p = 0.003, respectively) compared with the controls. The length of the pushing stage was similar among primiparas in all groups but prolonged compared with the controls in multiparas with patient-controlled intravenous analgesia with remifentanil (15 [17] vs. 5 [7] min, p = 0.001) and epidural analgesia (10 [15] vs. 5 [7] min, p = 0.006). The Apgar, umbilical arterial pH and base excess values were similar between the groups, as were the rates of acidosis and neonatal intensive care unit admission. Conclusion Parturients with patient-controlled intravenous analgesia with remifentanil and epidural analgesia showed a prolonged expulsive stage compared with the opioid group and controls. The short-term neonatal outcome was not influenced by the three methods examined.