Effect of goal-directed crystalloid- versus colloid-based fluid strategy on tissue oxygen tension: a randomised controlled trial

Background: Sufficient tissue oxygen tension may reduce the risk of postoperative wound infections. Supplemental administration of crystalloids increases subcutaneous oxygen tension (P_sqo₂). Colloids remain longer in the intravascular system and might therefore increase P_sqo₂ even more than crystalloids. Therefore, we tested the hypothesis that goal-directed colloid administration increases the perioperative P_sqo₂ more compared with crystalloid administration.

Methods: We randomly assigned 80 patients undergoing elective open abdominal surgery to receive fluid boluses of hydroxyethyl starch (HES) or lactated Ringer's (LR) solution guided by oesophageal Doppler. Intraoperative P_sqo₂ was measured in the upper arm. After operation, we measured the P_sqo₂ in the upper arm and in the surgical wound.

Results: Forty patients were enrolled in each group. Patients in the colloid group received HES solution 750 ml (500; 1000) and LR solution 1500 ml (1000; 2000). Patients in the crystalloid group received LR solution 2825 ml (2000; 3960). The goal-directed administration of colloids did not improve intraoperative P_sqo₂ in the arm compared with crystalloid administration (11.4 kPa [9.0; 16.6] vs 11.2 kPa [8.6; 15.1], respectively; P=0.58). Postoperative arm P_sqo₂ was 8.1 kPa (6.5; 9.6) in the colloid group and 7.3 kPa (5.7; 9.1) in the crystalloid group (P=0.11). Postoperative surgical wound P_sqo₂ was 10.7 kPa (8.6; 13.4) in the colloid group and 10.1 kPa (8.1; 12.7) in the crystalloid group (P=0.68).

Conclusions: Goal-directed colloid administration did not increase P_sqo₂ compared with goal-directed crystalloid administration in patients undergoing open abdominal surgery.

Clinical trial registration: NCT00517127.