Can we predict who will develop postoperative hyperkalaemia after parathyroidectomy in dialysis patients with secondary hyperparathyroidism?

BACKGROUND: Hyperkalaemia occurs frequently in many maintenance haemodialysis (MHD) patients after parathyroidectomy (PTX) with secondary hyperparathyroidism (SHPT). However, the clinical risk factors that predict postoperative hyperkalaemia are uncertain. METHODS: This retrospective cohort study included 90 maintenance haemodialysis patients aged ≥18 years who underwent PTX between April 2011 and April 2016 at Aerospace Center Hospital (Peking University Aerospace School of Clinical Medicine). Pre- and post-PTX surgery venous samples were measured in quadruplicate. We examined univariate associations with demographics, dialysis characteristics, laboratory values and medications. Hyperkalaemia was defined as serum potassium >5.3 mmol/L. RESULTS: Out of nighty patients, twenty-two (24.4%) developed postoperative hyperkalaemia, of whom sixteen (18.1%) developed hyperkalaemia on postoperative day 3. The univariate analysis showed that weight, dialysis duration, preoperative serum potassium, alkaline phosphate, triglyceride, and postoperative alkaline phosphate were independently associated with hyperkalaemia after parathyroidectomy. The univariate logistic regression model showed that preoperative serum potassium was the only independent factor that could predict hyperkalaemia after parathyroidectomy (odds ratio, 1.59; 95% confidence interval, 1.24-2.05). The optimal cut-off for pre-operative K was 3.9 mmol/L according to the receiver operating characteristic (ROC) curve. A higher incidence of postoperative hyperkalaemia was found in male and younger patients, but the difference was not statistically significant (p>0.05). CONCLUSIONS: Pre-operative serum potassium less than 3.9 mmol/L was associated with less hyperkalaemia post-operatively in end-stage renal disease (ESRD) patients undergoing PTX.