The brain relaxation and cerebral metabolism in stroke volume variation-directed fluid therapy during supratentorial...

Compared with goal-directed crystalloid therapy, goal-directed colloid therapy during high-risk surgery may improve postoperative outcome. Whether intraoperative fluid therapy based on goal-directed protocol with different types of fluid has distinctive effects on brain relaxation and cerebral metabolism during craniotomy remains unclear.

Forty patients with supratentorial brain tumors undergoing craniotomy were randomly assigned to either a Ringer's Lactate-based goal-directed group (LR group, n=20) or a 6% hydroxyethyl starch-based goal-directed group (HES group, n=20). The goal was achieved by maintaining a target stroke volume variation (SVV<13%) by volume loading with LR or HES throughout the procedure. The primary outcome is brain relaxation scales, an indirect evaluation of ICP; secondary endpoints include cerebral metabolism variables (jugular venous oxygen saturation [SjvO(2)], arterial-jugular venous differences in oxygen [CajvO(2)], glucose [A-JvGD], lactate [A-JvLD], and cerebral extraction ratio for oxygen [CERO(2)]) and fluid volumes.

There is no significant difference between the LR and HES groups on brain relaxation scales (P=0.845), or measures of cerebral oxygenation and metabolism. Intragroup comparisons showed that CERO(2) increased by 14.3% (P=0.009, LR group) and 13.2% (P=0.032, HES group), respectively, and SjvO(2) was decreased by 8.8% (P=0.016, LR group) and 8.1% (P=0.026, HES group), respectively, after tumor removal, compared with baseline. During surgery, the LR group (3070±1138 mL) received more fluid than the HES group (2041±758 mL, P=0.002).

In patients undergoing supratentorial tumor resection, goal-directed HES therapy was not superior to goal-directed LR therapy for brain relaxation or cerebral metabolism, although less fluid was needed to maintain the target SVV in the HES-based group than in the LR-based group.