[The effects of hypertonic lactated Ringer's solution during transurethral surgery]

We studied the plasma sodium level and osmolarity when hypertonic lactated Ringer's solution (HLS) with sodium of 213 mEq.l-1 was infused as intraoperative fluid in patients (n = 7) undergoing transurethral resection of the prostate (TUR-P). Regular lactated Ringer's solution was infused in other patients (n = 7) as the control drug. Plasma sodium level and plasma osmolarity decreased significantly in the patients with regular lactated Ringer's solution group. On the other hand, these changes were not observed in the patients of HLS groups. However, three hours after the administration, serum ADH level increased significantly in HLS group while it remained unchanged in control group. It was suspected that the increase in serum sodium concentration might have stimulated secretion of ADH after TUR-P. Our study suggests that the administration of HLS prevents the hyponatremia and hypoosmolarity in patients undergoing TUR-P and that the HLS could be used routinely during this procedure as the essential fluid therapy.