Hungry bone syndrome as a cause of recurrent laryngospasm after parathyroidectomy:

Factors influencing the development of bone starvation syndrome after total parathyroidectomy in patients with renal hyperparathyroidism

Purpose

To investigate the factors affecting the development of bone starvation syndrome (HBS) after total parathyroidectomy in patients with renal hyperparathyroidism (SHPT).

Patients and methods

The clinical data and perioperative indices of 141 patients who underwent PTX for SHPT were retrospectively analyzed. The patients were divided into HBS and non-HBS groups based on postoperative minimum blood calcium <1.87 mmol/L. The differences in general clinical data and perioperative related indices between the two groups were compared; logistic regression analysis was performed to analyze the risk factors influencing HBS occurrence after surgery. Multiple linear regression method was used to analyze the factors influencing the maintenance time of intravenous calcium supplementation and total amount of calcium supplementation during intravenous calcium supplementation. The threshold value for the diagnosis of HBS was analyzed using the ROC subjects' working curve.

Results

HBS occurred in 46 (32.6%) patients. Univariate analysis showed statistically significant differences in dialysis age, preoperative calcitonin, preoperative parathyroid hormone, preoperative blood phosphorus, and preoperative alkaline phosphatase between both groups (P < 0.05). Logistic regression analysis using stepwise entry method concluded that preoperative alkaline phosphatase was an independent factor for the development of HBS after surgery. Preoperative parathyroid hormone was an independent factor for the duration of intravenous calcium supplementation and total calcium supplementation during intravenous calcium supplementation in the HBS group. Based on the ROC curve, for postoperative HBS, the cut-off ALP value was 199.5 U/L, with a sensitivity of 80.85% and specificity of 82.61%.

Conclusion

Preoperative serum ALP may be an independent factor for HBS occurrence after surgery. When preoperative ALP > 199.5 U/L, patients with SHPT are prone to HBS after surgery, and the higher the preoperative ALP, the higher the incidence of HBS, and vice versa. In addition, preoperative PTH may be the factor in the timing of postoperative intravenous calcium supplementation and the total amount of calcium supplementation during intravenous calcium supplementation in patients with HBS.

Perioperative hyperkalemia in hemodialysis patients undergoing parathyroidectomy for renal hyperparathyroidism

The present study investigates the incidence of perioperative hyperkalemia and the influence factors of serum potassium levels during and after parathyroidectomy (PTX) in hemodialysis patients with renal hyperparathyroidism (rHPT). A total of 204 hemodialysis patients with refractory rHPT undergoing successful total parathyroidectomy with autotransplantation (tPTX + AT) were analyzed retrospectively. Hyperkalemia was defined as serum potassium levels ≥ 5.5 mmol/L. The preoperative baseline level of serum potassium (K _base⁺ ) was defined as a mean of the three preoperative prehemodialysis serum potassium levels. The higher levels of serum potassium during and immediately after surgery were recorded as K _d0⁺ and the peak prehemodialysis serum potassium levels 3 days after surgery as K _d3⁺ . 136/204 (66.7%) patients suffered from hyperkalemia during or immediately after surgery and 65/204 (31.9%) patients were affected with prehemodialysis hyperkalemia 3 days after surgery. K _base⁺ was the only influencing factor for K _d0⁺ . Serum K _base⁺ , preoperative serum alkaline phosphatase, and total calcium supplement dosage during intravenous calcium supplement were the influencing factors for K _d3⁺ . In the case of PTX, the serum potassium levels of patients with higher serum K _base⁺ and severe postoperative hypocalcemia need to be monitored with extended attention perioperatively.

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.

Hungry bone syndrome

PURPOSE OF REVIEW

In the United States, the number of parathyroidectomies among patients with chronic dialysis has remained stable in the last decade. A fall in serum calcium concentration is common postparathyroidectomy in patients with hyperparathyroidism, which usually resolves in 2-4 days. A severe drop in serum total calcium concentration less than 2.1 mmol/L and/or prolonged hypocalcemia for more than 4 days postparathyroidectomy is called hungry bone syndrome (HBS). Concomitant hypophosphatemia, hypomagnesemia, and hyperkalemia can be seen. Hypocalcemia and hypophosphatemia can persist for months to years. In contemporary clinical practice, HBS may be more commonly seen in patients with secondary compared to primary hyperparathyroidism. Preoperative radiological changes in bone, elevated serum alkaline phosphatase and parathyroid hormone (PTH) levels, and high numbers of osteoclasts on bone biopsy may identify patients at risk. Treatment consists of high-dose oral calcium and calcitriol supplementation. A low-dose pamidronate infusion 1-2 days prior to surgery may prevent HBS.

RECENT FINDINGS

Recent in-vitro studies reported net calcium movement into bone because of a sudden fall in serum PTH level after a prolonged period of elevation. This supports a previous hypothesis that a sudden drop in serum PTH level after surgery results in the unopposed action of osteoblasts and influx of calcium into bone.

SUMMARY

Incidence of HBS and its association with morbidity and mortality remains unclear in contemporary clinical practice. It is more common to encounter HBS in chronic dialysis patients with secondary hyperparathyroidism than those with primary hyperparathyroidism that undergo parathyroidectomies. Use of bisphosphonates to prevent HBS should be explored in future studies.

Intraoperative Hyperkalemia and Ventricular Arrhythmia During Parathyroidectomy: A Case Report

We present a case of acute hyperkalemia and ventricular arrhythmia during parathyroidectomy in a patient with end-stage renal disease. This case highlights the under-recognized alterations in potassium homeostasis associated with parathyroidectomy and underscores the importance of preoperative optimization.