Effect of 0.45% saline and plasmalyte A used during intraoperative and post-operative period on serum osmolality in patients undergoing craniopharyngioma surgery

Background: Electrolyte imbalance and acute diabetes insipidus (DI) are the most common complications in patients undergoing craniopharyngioma surgery. Data are sparse regarding the choice of fluid in patients undergoing craniopharyngioma excision. We compared the effects of iso-osmolar plasmalyte A and hypo-osmolar 0.45% saline infused perioperatively on perioperative serum osmolality, serum sodium level and incidence of DI. Methodology: A prospective randomised double-blind study was conducted in 28 patients undergoing transcranial excision of craniopharyngioma. The patients received either plasmalyte A or 0.45% normal salineintraoperatively and till 7^th post-operative day. Serum and urine osmolality, serum and urine sodium, urine specific gravity, Glasgow coma scale and total dose of desmopressin required were measured in the perioperative period and for up to 7 days post-operatively. Results: Demographic data were comparable. A statistically significant difference was found between the two groups in serum osmolality at 2 h (P = 0.033), 3 h (P = 0.009) after the start of surgery, at the end of surgery (P = 0.013) and on post-operative day 0 (P = 0.015) with 0.45% saline group having serum osmolality <300 mosm/kg as compared to plasmalyte group. The urine osmolality at 2 h (P = 0.03), at post- operative day 0 (P = 0.015) and post-operative day 1 (P = 0.010) was more than 300 mosm/kg in 0.45% saline group as compared to plasmalyte A group. Plasmalyte A group had hypernatremia (P = 0.015) as compared to 0.45% saline group on post-operative day 1. Discussion: 0.45% saline has better effect than plasmalyte A on serum osmolality in patients undergoing transcranial resection of craniopharyngioma.

No conflict of interest has been declared by the author(s).