Specific Aim I: Determine absorption of iodine after oropharyngeal application of povidone-iodine 10% solution when used in head and neck surgery involving the upper aero-digestive tract.

Specific Aim II: Measurement of iodine induced changes in thyroid function.

Serial blood draws will be obtained from approximately 10 men and women age 18 and over who have been exposed to intraoperative oropharyngeal application with povidone-iodine 10%. Baseline serum and 24-hour urine iodine levels will be measured preoperatively. Serum iodine levels will be drawn at 1 hour, 2 hours, 4 hours, 6 hours, 24 hours, 1 week, and 1 month after exposure. A postoperative 24-hour urine iodine level will also be obtained. With the above measurements, the amount of iodine absorption as well as the time period of peak absorption and duration of elevated iodine levels will be elucidated.

Thyroid hormone metabolism is highly dependent on serum levels of iodine. Thyroid function will be assessed by measuring serum levels of free thyroxine, free triiodothyronine, and thyroid stimulating hormone also at 1 hour, 2 hours, 4 hours, 6 hours, 24 hours, 1 week, and 1 month after exposure. Measuring thyroid function is important since hypothyroidism has been known to have a major impact on postoperative wound healing.

Inclusion Criteria:

• Patients undergoing any head and neck surgery requiring entry into the upper aerodigestive tract and thus necessitating the oral administration of the antimicrobial agent povidone-iodine 10%.

Exclusion Criteria:

• Patients with history of hypothyroidism currently taking thyroid hormone medications (i.e. Synthroid, Levothyroxine, Thyroxine) and women who are pregnant.

Primary Care Clinic