Fluid Restriction After Transsphenoidal Surgery for the Prevention of Delayed Hyponatremia: A Systematic Review and...

Delayed hyponatremia is the primary cause of readmission after transsphenoidal surgery, with a reported incidence of 9% to 30.7%. Studies have failed to identify consistent predictive factors for postoperative hyponatremia; thus, it is difficult to determine patients that are at a high risk. Fluid restriction is one approach for the prevention of hyponatremia. We have performed a meta-analysis and systematic review of the literature to evaluate the impact of fluid restriction on hyponatremia and hospital readmissions.

Ovid EMBASE, PubMed, Scopus, and Cochrane were searched from inception to May 2021, using the Population, Intervention, Comparison, Outcome, and Study question format: Do patients who underwent transsphenoidal surgery and followed a postoperative fluid restriction regimen differ in terms of hyponatremia and readmission rates? Studies that implemented fluid restriction and reported hyponatremia and/or readmission rates were included for analysis. Data were pooled by meta-analysis and analyzed using fixed effect and random effect models.

A total of 143 manuscripts representing 103 unique studies were identified, with 5 studies included for analysis, yielding a pooled cohort of 1586 patients: 594 on fluid restriction protocols and 992 control patients. Fluid restriction protocols ranged from 1.0 to 2.5 L and varied in the length time between postoperative days 1 to 15. Patients on fluid restriction had a decreased risk of hyponatremia (risk ratio: 0.34; 95% CI, 0.21-0.57; P < .00001) and readmission due to hyponatremia (risk ratio: 0.24; 95% CI, 0.09-0.63; P = .0038).

Postoperative fluid restriction after transsphenoidal surgery represents an effective method for the prevention of hyponatremia and hospital readmission and has the potential to decrease health care costs.