Prevention and Management of Hypocalcemia After Thyroidectomy

Educational Objectives

The goal of this program is to improve management of patients undergoing thyroidectomy,. After hearing and assimilating this program, the clinician will be better able to:

1. Utilize pre-, intra-, and postoperative strategies to minimize risk for hypoparathyroidism after thyroidectomy.

Summary

Preoperative considerations: ensure patients do not have gross abnormality in calcium homeostasis; 2014 article recommended assessment of vitamin D, nutritional status, and diabetic ketoacidosis; if level of vitamin D is <20 ng/mL, aggressive management before surgery is recommended, with oral supplementation of 50,000 IU of vitamin D per day

Intraoperative considerations

Preservation of blood supply: branch of inferior thyroid artery is susceptible to deformation; capsular dissection of thyroid enables preservation and identification of parathyroid glands; autotransplantation should be used judiciously because reimplantation may impair parathyroid function; color is insufficient for identifying condition of parathyroid gland; inspection of thyroid gland after removal is recommended to identify presence of any parathyroid tissue on outside

Considerations with Graves disease: thyroid glands are often inflamed and have dense fibrosis, which can cause the parathyroid glands to adhere to the thyroid; high vascularity can increase difficulty of preserving polar vessel of parathyroid

Postoperative considerations

Risk factors for hypoparathyroidism: publication from the American Association of Clinical Endocrinologists- American College of Endocrinology (AACE-ACE) states that risk factors include bilateral central neck dissection, surgery for thyroid malignancy, surgery for parathyroid hyperplasia, female sex, vitamin D deficiency, pregnancy and lactation, autoimmune thyroid disease, and gastric bypass surgery

Reoperative or completion surgery: status of parathyroid glands on the ipsilateral side is unclear (unless specified on pathology report); careful preservation of parathyroid glands on previously unoperated side is recommended

Subnumerary and supranumerary parathyroid glands: postmortem study from Sweden showed that ≈20% of individuals have 2, 3, 5, or 6 glands

Measuring parathyroid hormone (PTH): AACE-ACE publication states that protocols vary widely for intra- or postoperative measurement of PTH; measurement after completion of surgery indicates the amount of functional parathyroid tissue

Readings

Bai B et al: Risk factors and outcomes of incidental parathyroidectomy in thyroidectomy: a systematic review and meta-analysis. PLoS One. 2018 Nov 9;13(11):e0207088; Dedivitis RA et al: Hypoparathyroidism after thyroidectomy: prevention, assessment and management. Curr Opin Otolaryngol Head Neck Surg. 2017 Apr;25(2):142-146; Lawson BR et al: Relationship of vitamin D deficiency and intraoperative parathyroid hormone elevation in completion and total thyroidectomy. Otolaryngol Head Neck Surg. 2019 Apr;160(4):612-615.

Disclosures

For this program, members of the faculty and planning committees reported nothing to disclose.

Acknowledgements

Dr. Cottrill was recorded at Jefferson Thyroid Cancer and Parathyroid Disease: Updates in Diagnosis and Treatment, held on October 9, 2019, in Philadelphia, PA, and presented by Sidney Kimmel Medical College at Thomas Jefferson University, Department of Continuing Medical Education. For information on future CME activities from this sponsor, please visit cme.jefferson.edu. The Audio Digest thanks the speakers and Sidney Kimmel Medical College at Thomas Jefferson University, Department of Continuing Medical Education for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

ON111702

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.