Preoperative calcitriol reduces postoperative intravenous calcium requirements and length of stay in parathyroidectomy for renal-origin hyperparathyroidism.

Background: Patients undergoing subtotal parathyroidectomy for renal-origin hyperparathyroidism often develop postoperative hypocalcemia, requiring calcitriol and intravenous calcium (Postop-IVCa). We hypothesized that in subtotal parathyroidectomy for renal-origin hyperparathyroidism, preoperative calcitriol treatment reduces the use of postoperative administration of intravenous calcium.

Methods: A retrospective chart review compared subtotal parathyroidectomy for renal-origin hyperparathyroidism patients who received preoperative calcitriol treatment with those patietns who did not receive preoperative calcitriol treatment at one institution. Preoperative calcitriol treatment loading doses were 0.5 mcg twice daily for 5 days. All patients received postoperative calcitriol and oral calcium carbonate. Postoperative administration of intravenous calcium was given for symptoms, calcium <7.0 mg/dL, or surgeon preference. The Fisher exact test was used to compare proportions. The Wilcoxon test was used to compare continuous data. Multivariable logistic regression adjusted for confounders.

Results: Included were 81 patients who received subtotal parathyroidectomy for renal-origin hyperparathyroidism (41 patients who received preoperative calcitriol treatment, 40 patients who did not receive preoperative calcitriol treatment). Preoperative calcitriol treatment use increased over time (0% 2004-2010, 69% 2011-2016). Groups who received preoperative calcitriol treatment and groups who did not receive preoperative calcitriol treatment were similar in preoperative serum calcium, vitamin D, parathyroid hormone, and median age (P > .05 for all). Patients who received preoperative calcitriol treatment less often required postoperative administration of intravenous calcium (34% vs 90% of patients who did not receive preoperative calcitriol treatment, P < .001). Median length of stay was 2.0 days shorter for patients who received preoperative calcitriol treatment versus patients who did not receive preoperative calcitriol treatment patients (P < .001). Factors associated with postoperative administration of intravenous calcium included not receiving preoperative calcitriol treatment, low preoperative calcium, and high preoperative parathyroid hormone. After multivariable adjustment, preoperative calcitriol treatment remained independently associated with reduced postoperative administration of intravenous calcium (OR 0.02, P < .001).

Conclusion: Preoperative calcitriol therapy lowered use of postoperative administration of intravenous calcium by 56% and length of stay by 50% in subtotal parathyroidectomy for renal-origin hyperparathyroidism patients. We believe preoperative calcitriol treatment should become standard of care for subtotal parathyroidectomy for renal-origin hyperparathyroidism.