Endocrine Abstracts

Introduction: Fluid and sodium disorders are a relatively frequent occurrence after sellar/supra-sellar surgeries. National Hospital of Sri Lanka (NHSL) is the main tertiary care centre in Sri Lanka, conducting regular pituitary surgeries.

Methods: A prospective cross-sectional study was conducted in all adults (above 15-years) undergoing pituitary-related surgeries in NHSL over 18 months from September 2019. The relationship between demographic factors, clinical, biochemical & tumour characteristics, diagnosis and indication for surgery, type and attempt of surgery with the post-operative fluid and sodium outcomes [syndrome-of-inappropriate-anti-diuretic-hormone (SIADH), polyuria, Cranial Diabetes Insipidus (CDI)] were analysed.

Results: There were 139 patients with a mean age of 44 years (+/- 15), 60% females, undergoing Trans-sphenoidal-surgery(TSS) or craniotomy for varying indications related to sellar/supra-sellar pathologies. Mean baseline pre-operative sodium was 138.9 (+/-3.2). Post-operatively, 76(54.6%) developed polyuria (>3l/24-h) with peak median urine output on day 2. Out of them, 52 (68.5%) were diagnosed with CDI (80.7% having only transient CDI) and the rest had transient polyuria without confirmed Cranial-Diabetes-Insipidus (TPWCDI). Out of all polyuric patients, 71 received at least a single dose of Desmopressin at some point. Twenty-eight (20.1%) developed post-operative hyponatremia (sodium<135), with only 12(8.6%) having confirmed SIADH. All SIADH patients were managed with fluid restriction, with only 2 requiring hypertonic saline. Five demonstrated triple phase response. Patients undergoing re-operation had a significant association with confirmed CDI & TPWCDI, compared to first surgery (P<0.0001 & P=0.03 respectively). However, none developed SIADH. Risk of CDI was higher in patients with a tumour size of >2 cm (OR-1.37;95%CI-1.08-1.726; P=0.018). Craniopharyngioma demonstrated a higher risk of post-operative CDI compared to other diagnoses (OR-6.8;95%CI 2.7-17;P<0.0001).

Acromegaly patients had a higher risk of post-operative TPWCDI (OR-1.46; 95%CI 1.04-2.06; P<0.0001) and none developed CDI. Post-operative SIADH was more likely in patients undergoing craniotomy, than TSS (P=0.001). Patients with tumour size>3 cm (OR1.6; 95%CI 1.2-2;P<0.0001), and craniopharyngioma (OR 2.9; 95%CI 1.1- 7.2; P=0.02) were more at risk of SIADH. SIADH was not seen with acromegaly or Cushing’s.

Conclusions: Transient fluid & sodium disorders occurred in majority of the patients undergoing pituitary-related surgeries. Polyuria & CDI were more common than SIADH. Re-operation, tumour size and the type of tumour could be predictors of post-operative fluid and sodium disorders. The findings of this real-world study add to the existing global literature and is the first such study conducted in Sri Lanka.