BACKGROUND: Delayed symptomatic hyponatremia (DSH) is among the most common reasons for readmission following transsphenoidal surgery. Patients can present with a large range of symptoms, requiring immediate attention and prolonging hospital stay. In rare and severe cases, DSH can result in death. While various risk factors for DSH have been investigated, there is still a need for better understanding in order to identify patients who are at risk. Clinicians can then take preventative measures to improve patient outcomes. A systematic review was performed to determine both predictors and rates of DSH after both endoscopic (eTSS) and microscopic transsphenoidal surgery (mTSS).
METHODS: We conducted a systematic search through databases MEDLINE/PUBMED, MEBASE, and The Cochrane Library. Included studies were selected with the following criteria: (i) case series with at least 10 cases reported, (ii) adult patients who underwent eTSS or mTSS for pituitary adenomas, and (iii) reported occurrence of DSH (hyponatremia defined as blood sodium level <135 mEq/L) three days post-operatively. Data were analyzed using CMA V.3 Statistical Software (2014).
RESULTS: We identified 10 case series that satisfied the inclusion criteria consisting of 2,947 patients with pituitary adenomas. The following were investigated as potential predictors of DSH: age, CSF leak, gender, and tumor size. Rates of DSH were found to be between 4 and 12 percent for both mTSS and eTSS.
CONCLUSIONS: Age, gender, tumor size, rate of blood sodium level decline between post-operative day (POD) 4 and 7, and Cushing’s disease are potential predictors of DSH. A better understanding of these predictors can help clinicians identify patients at risk for DSH so preventative measures can be taken to reduce the deleterious effects of hyponatremia after transsphenoidal surgery
