Effects of hypertonic saline - hydroxyethyl starch and mannitol on serum osmolality, dural tension and hemodynamics in patients undergoing elective neurosurgical procedures

Abstract

Objective: To investigate effect of equal volumes (250 ml) of 7.2% hypertonic saline - 6% hydroxyethyl starch (HS-HES) and 20% mannitol (M) on dural tension, serum osmolality and hemodynamics in patients during elective neurosurgical procedures.

Material and methods: Forty ASA I-II patients scheduled for elective neurosurgical supratentorial procedures were randomly assigned to two groups. About 30 min before skull opening, patients received either HS-HES or M at infusion rate 750 ml/h. Dural tension score was used to evaluate the dural tension by neurosurgeons. Serum osmolality was tested at following time points: before, 125 ml infused, 250 ml infused, 30 min and 60 min after infusion. Hemodynamic variables were measured by FloTrac.

Results: Patients who received HS-HES had a significant decrease in dural tension scores (P < 0.05) and obtained more satisfactory brain relaxation for neurosurgeon (95% vs. 75%). In HS-HES group, the peak of serum osmolality occurred earlier and hyperosmolality lasted for longer time. Transient decrease in mean arterial pressure was observed in M group at 10 min after the start infusion (P < 0.01). Heart rate significantly decreased after HS-HES infusion, whereas no significant changes were observed in M group. In HS-HES group, stroke volume variation significantly decreased from 9.7 ± 3.5 at the initiation of infusion to 6.7 ± 2.4 at 30 min after the infusion and remained decreased more than 60 min while it decreased from 6.8 ± 3.1 to 5.3 ± 1.5 in M group. Moreover, urine output in HS-HES group from initiation to 60 min after the infusion was significantly less than those in M group.

Conclusion: HS-HES might be an alternative to mannitol in treatment of intracranial hypertension.

Keywords: Hypertonic saline; dural tension; hydroxyethyl starch; mannitol; neurosurgery anesthesia.