Hypertonic saline solution: a safe alternative to mannitol 18% in neurosurgery.

BACKGROUND

To evaluate the usefulness of hypertonic saline solutions (HTS) as an alternative to mannitol in neurosurgery.

METHODS

Thirty patients subjected to craniotomy for supratentorial cerebral tumors were randomly divided in to three Groups: M: had mannitol 0.5 g.kg-1 as bolus at the start of skin incision, and postoperatively 0.5 g.kg-1 daily three times a day for 3 days (72 hrs); HM: had mannitol 0.25 g.kg-1 as bolus at the start of skin incision plus 3% HTS, 20 ml.h-1 intraoperatively and mannitol 0.25 g.kg-1 daily three times a day for 3 days plus HTS in the concentration of 3% in the first day and 2% and 1% the second and the third day after surgery; H: had 3% HTS 3.5 ml kg-1 as bolus at the start of skin incision plus 3% HTS, 20 ml hr-1 intraoperatively and 3% HTS, 20 ml h-1 on the first day and 2% and 1% the second and the third day after surgery. FR, MAP, ICP, CVP and diuresis were continuously monitored intraoperatively and postoperatively for 72 hrs. ICP was monitored intraoperatively until dural opening and in the postoperative period for 72 hrs at least.

RESULTS

Diuresis was increased in the first and second Group (M and HM) more than in the H Group especially in the postoperative period, but this change was not a significative one (35.31 ml.kg-1.h-1+/-4.57 and 36.56+/-3.92 vs 3.23 ml.kg-1.h-1). Mean serum Na+ values declined in the postoperative period, in Groups M and MH and remained stable in the postoperative period in the Group H (137.6+/-7 mEq.l-1 and 136.5+/-6.5 mEq.l-1 vs 139.2+/-5 mEq.l-1). Serum osmolality increased significantly in the postoperative period in group H and remained unchanged in the same period in Group M and MH. Potassium values declined significantly during the whole period in all groups but remained in a normal clinical range. CVP values decreased in Groups M and MH in the postoperative period, and increased although not significantly in the postoperative period in the Group H patients. Ht values declined significantly in all groups without differences among the groups although the reduction was greater in group H.

CONCLUSIONS

HTS can safely be used in humans they obtain a reduction of ICP without reducing CVP, serum osmolality and Na+ serum values. Our data underline the possibility of their use as an alternative to mannitol in the treatment of patients scheduled for intracranial surgery, especially when multiple doses are needed.