A PROTOCOL-BASED INTRAVENOUS CALCIUM GLUCONATE THERAPY IN AN OUTPATIENT ENVIRONMENT FOR CHRONIC HYPOCALCAEMIA ASSOCIATED WITH PARATHYROIDECTOMY IN PATIENTS UNDERGOING HEMODIALYSIS

Hyperparathyroidism is frequently observed in patients undergoing hemodialysis. A significant number of these patients ultimately require parathyroidectomy. Following parathyroidectomy, patients commonly face hypocalcemia, which is characterised by adjusted calcium (adjCa) levels below 2.2 mmol/L. To mitigate the consequences of chronic hypocalcaemia, various established guidelines recommend maintaining adjCa levels within the range of 2.2 to 2.6 mmol/L. Should levels persist below this threshold, patients are generally transitioned to a high calcium dialysate of 1.75 mmol/L, in conjunction with vitamin D and oral calcium supplements. Nevertheless, the considerable pill burden experienced by hemodialysis patients often leads to non-compliance, which in turn results in chronic persistent hypocalcaemia. At present, there are no effective strategies to address non-compliance and rectify persistent hypocalcemia in this patient cohort, thereby preventing recurrent hospitalisations for intravenous (IV) calcium therapy. As an innovative approach, we initiated administering IV calcium gluconate intradialytic within the outpatient dialysis unit. This study aims to evaluate the safety and efficacy of intradialytic IV calcium gluconate therapy for these patients to reduce the need for recurrent hospitalisation.

This is a retrospective observational audit focused on adult hemodialysis patients aged over 18 years who underwent parathyroidectomy within the last 12 months and still demonstrated pre-dialysis adjusted calcium (adjCa) levels consistently below 2.2 mmol/L for a minimum of three consecutive months, despite being already on the maximum standard treatment regimen, which included a high calcium dialysate concentration of 1.75 mmol/L, intravenous vitamin D supplements, and oral calcium tablets as required, to keep adjCa levels within the desired range of 2.2 to 2.6 mmol/L. In the following six months, each participant was administered a maintenance dose of 10 mL of 10% intravenous calcium gluconate after every dialysis session, three times weekly. Adjusted calcium levels were assessed in the middle of each month.

A total of nine patients satisfied the inclusion criteria. All participants receiving intravenous calcium-gluconate supplementation three times a week successfully maintained their pre-dialysis adjCalcium levels above 2.2 mmol/L throughout the 6-month follow-up period, with no incidence of hypercalcemia. None of the patients needed hospital admissions due to hypocalcemia. The graph below depicts the median adjusted calcium levels prior to and following the intervention.

The short term outcome of our intervention demonstrated effectiveness and were reassuringly safe. This suggests that alternative approaches, like intradialytic IV calcium gluconate, are suitable for outpatient settings and merit further exploration within the hemodialysis population that struggles with compliance to oral therapies. This technique may also help prevent hospitalizations for intravenous calcium treatment. However, we recommend additional validation before drawing more conclusive insights about this approach. It is important to recognize that the study has specific limitations, being a retrospective analysis with a relatively small sample size.