Comparison of normal saline and balanced crystalloid (plasmalyte) in patients undergoing elective craniotomy for supratentorial brain tumors: A randomized controlled trial.

Background: The choice of fluid is important in neurosurgical patients, who may be dehydrated due to the administration of diuretics in order to reduce cerebral edema. Normal saline, the infused fluid routinely used in neurosurgical patients, can cause hyperchloremic metabolic acidosis. A balanced crystalloid (BC) may help to maintain the metabolic status more favorably in these patients, without adversely affecting brain relaxation.

Methods: We conducted a prospective, randomized controlled trial on patients undergoing elective craniotomy for supratentorial tumor resection under general anesthesia. 44 patients were randomly allocated into two groups of 22 each to receive either normal saline or BC (Plasmalyte) as the maintenance fluid, intra-operatively. The metabolic parameters and osmolality were measured at regular intervals. Brain relaxation score was assessed by the operating surgeon. The patients were monitored with serum neutrophil gelatinase-associated lipocalin (NGAL), blood urea and serum creatinine for assessing the degree of acute kidney injury.

Results: The metabolic profile was better maintained with the BC. The brain relaxation score was comparable between the two groups. The postoperative NGAL, urea and creatinine values were significantly higher in the normal saline group compared to the BC group.

Conclusion: The balanced crystalloid maintains metabolic status more favorably than normal saline in neurosurgical patients. Hyperchloremic metabolic acidosis, and the other problems which occur as a consequence of normal saline infusion may be circumvented by choosing a balanced crystalloid electrolyte solution. Neither of the crystalloids appeared to have any adverse effect on brain relaxation.