Professor of Neurosurgery Cedars-Sinai Medical Center Los Angeles, California, United States
Introduction: Symptomatic delayed hyponatremia is a major cause of morbidity and hospital readmission after transsphenoidal pituitary surgery (TSS). Prophylactic fluid restriction (FR) protocols after surgery may reduce rates of symptomatic hyponatremia and readmissions.
Methods: Patients who underwent TSS were discharged with a one-liter fluid restriction protocol. Serum sodium levels were measured on post-operative day (POD) 7 with telephone follow-up. Rates of hyponatremia and readmissions were compared to a cohort of 316 patients treated prior to the protocol. Numerical variables were summarized as mean ± SD and significance testing calculated by Chi-square and t-test.
Results: Ninety-three patients were included in the analysis, of whom 74.3% had pituitary adenomas. Hyponatremia occurred in 13/93 (14%) patients. Mean POD 7 sodium was 137.9 mmol/L. Two patients (2.1%) were readmitted for hyponatremia, and 3 re-admitted for other causes. 88/93 (94.6%) of patients complied with the FR protocol. Of 5 non-compliant patients, 2 developed hyponatremias (40%) compared to 3/88 (3.4%) in those who complied (p=0.008). Mean POD7 sodium was 138 (+/-4.5) mmol/L in those that complied and 135 (+/- 4.7) mmol/L in those who did not. Overall readmission rate for those with postoperative hyponatremia was 23% compared to 2.5% for those with normal sodium levels (p=0.0023). In 316 patients treated prior to the FR protocol, 78 (24.7%) developed delayed hyponatremia with 6% readmitted for hyponatremia. Compared to patients not on FR, patients on the FR protocol had 50% reduced risk of hyponatremia (OR=0.49 (95% CI 0.26-0.94, p=0.03), and a 3-fold reduced risk of overall readmissions (OR=0.31; 95% CI 0.12-0.81, p=0.0157) and readmission for hyponatremia (OR= 0.34 ;95% CI 0.08-1.5, p=0.16).
Conclusion : Instituting a one-liter daily FR protocol in patients after TSS results in significantly reduced rates of hyponatremia, overall readmissions, and readmission for hyponatremia. A post-operative FR protocol should become routine practice for patients undergoing pituitary surgery
