Preoperative mineralocorticoid receptor antagonist reduces postoperative hyperkalaemia in patients with Conn syndrome.

BACKGROUND: The preoperative use of mineralocorticoid receptor antagonists (MRA) in patients with unilateral forms of primary aldosteronism (PA) is not standardized. The current Endocrine Society Guidelines do not specifically recommend MRA treatment before surgery. It is unclear whether preoperative MRA can optimize perioperative blood pressure and potassium control, and reduce the incidence of postoperative hyperkalaemia. OBJECTIVE: This study aimed to investigate the effect of MRA on the incidence of postoperative hyperkalaemia in addition to perioperative blood pressure and potassium concentration in patients undergoing unilateral adrenalectomy for the treatment of PA. DESIGN: Retrospective cohort study. SETTING: Tertiary referral centres, Victoria, Australia. PATIENTS: A total of 96 patients who were diagnosed with unilateral forms of PA: 73 patients ('MRA' group) received preoperative MRA while 23 patients ('No-MRA' group) did not. RESULTS: The prevalence of postoperative hyperkalaemia was significantly higher in the 'No-MRA' group at 2-4 weeks after surgery, compared to the 'MRA' group (35% vs. 11%, p = .014). In a logistic regression, the use of MRA significantly predicted a lower incidence of postoperative hyperkalaemia after adjusting for age, sex, baseline aldosterone-to-renin ratio, potassium and preoperative eGFR. Before surgery, patients in the 'MRA' group had normalized blood pressure and potassium concentration requiring fewer antihypertensive medications and no potassium supplements. CONCLUSION: Preoperative MRA use was associated with optimal perioperative blood pressure and normalized serum potassium in addition to a lower incidence of postoperative hyperkalaemia. MRA should be considered standard treatment for patients awaiting surgery for PA.

Temporal analysis of thyroid cancer management in a Melbourne tertiary centre.

BACKGROUND: The American Thyroid Association (ATA) management guidelines for thyroid cancer were revised in 2009. The aim of this study was to determine if management of thyroid cancer in our institution has changed in accordance with the introduction of the revised ATA guidelines (ATA2009 ), and to compare the characteristics and management of thyroid cancer in a Melbourne endocrine surgery unit over a 7-year period. METHODS: All patients treated by the Monash University Endocrine Surgery Unit for thyroid cancer between 2007 and 2013 were divided into two groups - the pre-ATA2009 group (2007-2010) and the post-ATA2009 group (2011-2013). Comparisons were made of the demographics, cytology, pathology, surgical outcome and adjuvant therapy using t-test and chi-squared tests. RESULTS: There were 333 patients in the pre-ATA2009 group and 342 patients in the post-ATA2009 group. Fewer non-diagnostic fine-needle aspiration cytology results were identified in the post-ATA2009 group (4% versus 0.9%; P = 0.01), while the rates of other fine-needle aspiration cytology categories were similar. There was a reduction in the use of radioactive iodine ablation in the post-ATA2009 group, both in the proportion of patients being treated (66% versus 48%; P < 0.001) and the dosages used (mean 96 mCi versus 80 mCi; P < 0.01), despite similar tumour size in both groups. CONCLUSION: The key changes in practice thought to be attributable to the 2009 revised ATA guidelines were the reduction in the use and dosage of radioactive iodine in the management of differentiated thyroid cancer.

Evidence for the role of perioperative PTH measurement after total thyroidectomy as a predictor of hypocalcemia.

BACKGROUND: Total thyroidectomy is now accepted worldwide as the standard surgical procedure for the management of benign bilateral nodular thyroid disease. Hypocalcemia is the most common complication of that procedure and a variety of strategies for diagnosing and managing post-thyroidectomy hypocalcemia have been advocated. Increasingly, the use of intact parathyroid hormone (PTH) has been utilized to try to predict those patients at risk of developing post-thyroidectomy hypocalcemia. METHODS: A Medline search of English language literature was performed and we reviewed the evidence in relation to the following three issues: the accuracy of PTH in predicting hypocalcemia, the optimal timing for measuring PTH, and the routine use of oral calcium supplements. RESULTS: Post-thyroidectomy PTH levels accurately predict hypocalcemia but lack 100% accuracy. Progressive and severe hypocalcemia is unlikely in the setting of a normal PTH level and hence PTH can be cautiously used to facilitate discharge within 24 h for many patients. In addition, PTH levels can be used to implement early treatment with calcium and/or vitamin D supplements to reduce the incidence and severity of hypocalcemia. A single PTH measurement taken any time from 10 min to several hours postoperative will provide equally accurate results for predicting post-thyroidectomy hypocalcemia. Routine use of oral calcium supplements may reduce the incidence and severity of post-thyroidectomy hypocalcemia. CONCLUSION: Postoperative PTH can be used to stratify the risk of patients developing hypocalcemia after thyroidectomy. In addition, the routine use of oral calcium supplements can lead to decreased incidence and severity of post-thyroidectomy hypocalcemia. Protocols based on PTH and the routine use of oral calcium supplements can lead to improved patient outcomes after thyroidectomy.