A Practical Protocol: Identifying Thyroidectomy Patients at Low Risk for Significant Hypocalcemia

CHICAGO, ILL. – Researchers from Johns Hopkins School of Medicine have identified a means of detecting thyroidectomy patients who can safely be discharged early after surgery, with little risk of developing significant hypocalcemia.

The research was sparked because there are an increased number of thyroid operations in the U.S. and around the world, began Tarik Y. Farrag, MD, Department of Otolaryngology-Head & Neck Surgery, Division of Endocrinology and Metabolism, Johns Hopkins School of Medicine, Baltimore, Md. We thought it was important to develop a protocol to help identify those patients who are at risk for developing significant hypocalcemia. This protocol could then be used to shorten length of stay for hospitalized patients at low risk, thus saving costs. Dr. Farrag outlined the protocol and the research that led to it in his Triological Society presentation at the Combined Otolaryngological Spring Meetings (COSM), A Safe and Cost Effective Short Hospital Stay Protocol to Identify Patients at Low Risk for the Development of Significant Hypocalcemia following Total Thyroidectomy.

Hypocalcemia is considered the most common complication following bilateral thyroidectomy, reported Dr. Farrag. Significant hypocalcemia can be life-threatening and may not manifest until after the patient is discharged from the hospital. The literature says two things, said Dr. Farrag, to monitor all patients for 48 hours before discharge, and to discharge patients after 24 hours, and send them home with calcium and vitamin D supplements. There is no consensus agreement on identifying the risk of hypocalcemia.

Therefore, Dr. Farrag and his colleagues set out to develop an algorithm that could identify patients at low risk for hypocalcemia, who can be considered suitable for earlier discharge.

Calculating the Risk of Hypocalcemia

We performed a retrospective chart review of 135 patients, explained Dr. Farrag. All charts were from 2001 to 2005, and included 45 males and 90 females. Researchers examined clinical notes and compared serum calcium (Ca) levels for each patient at 6 hours and at 12 hours after surgery.

Patients were divided into two groups: those with positive calcium slope and those with non-positive, said Dr. Farrag. Positive slope refers to an increased rate of change of serum Ca levels between the two time periods; non-positive describes no change or a decreased rate of change over the same period.

The number of patients in each group (positive slope and non-positive slope) who experienced significant hypocalcemia was then compared in order to assess whether the rate of change in the serum Ca level over time could predict significant hypocalcemia.