By Jill Stein
CHICAGO -- October 15, 2009 -- Researchers have developed a protocol for use of oral calcium that thwarts the development of symptomatic hypocalcaemia in most patients who have undergone outpatient parathyroidectomy.
Marie Vasher, MD, University of South Florida, Tampa, Florida, reported the data on October 14 in a poster session at the American College of Surgeons (ACS) 95th Annual Clinical Congress.
Dr. Vasher and colleagues conducted a study to determine the amount and duration of supplemental oral calcium in 6,000 patients who were undergoing parathyroidectomy for primary hyperparathyroidism. All patients were discharged within 2.5 hours of their procedure.
Dr. Vasher described the protocol for postoperative calcium supplementation after parathyroidectomy as follows: "The number of calcium tablets [315 mg calcium citrate each tablet] prescribed to individual patients varies according to their preoperative calcium levels and findings at surgery [adenoma versus hyperplasia]."
"Tablets are spaced evenly throughout the day," she said. "The maintenance dose is anticipated to last 2 years or longer based upon bone densitometry results and is supplemented with calcium supplied by a multivitamin and increased as needed for significant osteoporosis. Patients with an adenoma who are undergoing a biopsy of all 4 parathyroid glands during surgery, patients who have had more than 1 parathyroid gland removed, and patients who are morbidly obese are given 1 extra pill per day for the first 2 weeks. Postmenopausal women with T-scores <2.5 are given 1 extra pill per day starting on week 1. All patients are started on a multivitamin containing 500 mg calcium carbonate daily at the beginning of week 2."
Overall, 7 parameters had a significant impact on the amount of calcium needed to prevent symptomatic hypocalcaemia (P < .05). These included a preoperative serum calcium >12, >13, or 14 mg/dL; bone density T-score <=3; morbid obesity; the removal of >1 parathyroid gland; and manipulation/biopsy of all remaining glands.
Each independent variable increased the daily calcium requirement by 315 mg/day.
Using the protocol, fewer than 8% of patients manifested symptoms of hypocalcaemia. Most patients who did show hypocalcaemia symptoms successfully "self-treated" with additional oral calcium.
Overall, 7 patients (0.1%) presented to the emergency room for intravenous calcium on the third postoperative day or later.
Dr. Vasher said that patients undergoing a successful parathyroid operation for primary hyperparathyroidism could be discharged immediately without the need for hospital monitoring and added that all patients should be started on supplemental oral calcium within 3 hours of surgery in an amount that decreases over several weeks.
She emphasised that verbal and written patient education as well as the provision of calcium pills directly to the patient are essential for compliance.
[Presentation title: Postoperative Calcium Requirements in 6,000 Patients Undergoing Outpatient Parathyroidectomy: Easily Avoiding Symptomatic Hypocalcemia. Abstract SE109-W]
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