Predictors and Rates of Delayed Symptomatic Hyponatremia after Transsphenoidal Surgery: A Systemastic Review

Abstract

Background Delayed symptomatic hyponatremia (DSH) is a known complication of transsphenoidal surgery that can lead to prolonged hospital stay, readmission, and in rare cases, death. Many potential predictors for development of DSH have been investigated. A better understanding of DSH risk can lead to better patient outcomes. We performed a systematic review to determine the rates and predictors of DSH after both endoscopic transsphenoidal surgery and microscopic transsphenoidal surgery. Methods A systematic search of the literature was conducted using MEDLINE/PUBMED, EMBASE, and Cochrane databases. Inclusion criteria were 1) case series with at least 10 cases reported, 2) adult patients who underwent eTSS or mTSS for pituitary tumors, and 3) reported occurrence of DSH (defined as serum sodium level <135 mEq/L with associated symptoms) after postoperative day 3. Data were analyzed using CMA V.3 Statistical Software (2014). Results Ten case series satisfied the inclusion criteria for a total of 2947 patients. Various factors including age, gender, cerebrospinal fluid leak, and tumor size were investigated as potential predictors of DSH. DSH event rates for both mTSS and eTSS fell between around 4 and 12 percent and included a variety of proposed predictors. Conclusions Age, gender, tumor size, rate of decline of blood sodium, and Cushing disease are potential predictors of DSH. By identifying patients at high risk for DSH, preventative efforts can be implemented in the perioperative setting to reduce the incidence of potentially catastrophic hyponatremia following transsphenoidal surgery.