Affiliation: | aDepartment of Otolaryngology-Head and Neck Surgery, Boston University Medical Center, Boston, MA bSection of Endocrinology, Diabetes and Nutrition, Boston University Medical Center, Boston, MA cDepartment of Endocrinology, Walter Reed Army Medical Center, Washington, DC dDepartment of Otolaryngology-Head and Neck Surgery, Walter Reed Army Medical Center, Washington, DC eDepartment of Otolaryngology-Head and Neck Surgery, Jewish General Hospital, McGill University, Montreal, Canada fDivision of Otolaryngology-Head and Neck Surgery, Duke University, Durham, NC gDepartment of Otolaryngology, University of Manitoba, Winnipeg, Manitoba, Canada hDepartment of Surgery, Mayo Clinic, Rochester, MN iDepartment of Surgery, University of Hong Kong Medical Centre, Queen Mary Hospital, Hong Kong, China jDivision of Endocrine Surgery, Department of Surgery, Università Cattolica del Sacro Cuore, Rome, Italy kDepartment of Otolaryngology/Head and Neck Surgery, Oregon Health Sciences University, Portland, OR lSchools of Nursing and Medicine, Vanderbilt University, Nashville, TN. |
Abstract: | BACKGROUND: Monitoring for hypocalcemia after thyroidectomy, using only symptoms and serum calcium levels, can delay the discharge of patients who will remain normocalcemic and can delay the treatment of hypocalcemic patients. STUDY DESIGN: We conducted a systematic search for articles describing use of parathyroid hormone (PTH) assay, checked within hours of completing thyroidectomy, to predict postoperative symptomatic hypocalcemia. Studies were excluded if all patients were treated with postoperative calcium, or if early PTH values were used to alter management of the patient. Individual patient data (perioperative PTH and calcium levels, development of hypocalcemia) were obtained for 457 patients from the corresponding authors of 9 studies and pooled to yield the following results. RESULTS: PTH, checked at three time periods after removal of the thyroid gland (0 to 20 minutes, 1 to 2 hours, and 6 hours), was substantially lower in patients who became hypocalcemic compared with those who remained normocalcemic. The accuracy of PTH in determining hypocalcemia increased with time and was excellent when checked 1 to 6 hours postoperatively. A single PTH threshold (65% decrease compared with preoperative level), checked 6 hours after completing thyroidectomy, had a sensitivity of 96.4% and specificity of 91.4% in detecting postoperative hypocalcemia. CONCLUSIONS: PTH assay, when checked 1 to 6 hours after thyroidectomy, has excellent accuracy in determining which patients will become symptomatically hypocalcemic. Routine use of this assay should be considered because it may allow earlier discharge of the normocalcemic patient and earlier identification of patients requiring treatment of postthyroidectomy hypocalcemia. |