What is the workup for an inpatient with elevated Thyroid-Stimulating Hormone (TSH) level of 8?

From the Guidelines

For an inpatient with a TSH of 8, the initial workup should include ordering additional thyroid function tests, such as free T4, to evaluate the severity of hypothyroidism, as recommended by the 2021 ASCO guideline update 1.

Initial Evaluation

The patient's TSH level of 8 falls into the category of grade 1 hypothyroidism, as defined by the ASCO guideline, where TSH is between 4.5 and 10 mIU/L and the patient is asymptomatic 1.

• Check TSH and free T4 levels to confirm the diagnosis and assess the severity of hypothyroidism.
• Evaluate for symptoms of hypothyroidism, such as fatigue, cold intolerance, and constipation.
• Consider ordering anti-thyroid peroxidase (anti-TPO) antibodies to evaluate for autoimmune thyroiditis.

Management

According to the ASCO guideline, for grade 1 hypothyroidism, the patient should continue to be monitored with TSH checks every 4-6 weeks, with the option to include free T4 levels 1.

• The patient can continue with routine care and monitoring, without immediate initiation of levothyroxine therapy, unless symptoms worsen or TSH levels increase above 10 mIU/L.
• If symptoms develop or TSH levels increase, consider initiating levothyroxine therapy, with a starting dose of 1.6 mcg/kg/day, typically 75-100 mcg daily for most adults, and adjust based on age, weight, and comorbidities.
• Monitor TSH levels every 4-6 weeks initially, adjusting the dose as needed, and target a TSH within the normal range, typically between 0.4-4.0 mIU/L.

Follow-up

Upon discharge, ensure the patient has a follow-up appointment with an endocrinologist or primary care physician within 4-6 weeks for repeat thyroid function tests and dose adjustment if necessary.

• Educate the patient about the importance of consistent medication adherence and regular follow-ups for optimal thyroid management.
• Consider ordering a lipid panel and basic metabolic panel, as hypothyroidism can affect these parameters, as noted in the 2004 JAMA study 1.

From the FDA Drug Label

The general aim of therapy is to normalize the serum TSH level In adult patients with primary hypothyroidism, monitor serum TSH levels after an interval of 6 to 8 weeks after any change in dosage.

The workup for an inpatient with an elevated Thyroid-Stimulating Hormone (TSH) level of 8 includes:

• Monitoring serum TSH levels after an interval of 6 to 8 weeks after any change in dosage
• Evaluating clinical and biochemical response every 6 to 12 months and whenever there is a change in the patient’s clinical status
• Normalizing the serum TSH level is the general aim of therapy 2 2 2

From the Research

Workup for Elevated TSH Level

The workup for an inpatient with an elevated Thyroid-Stimulating Hormone (TSH) level of 8 involves several steps:

• Checking the patient's medical history and current medications to identify any potential causes of the elevated TSH level 3, 4
• Ordering laboratory tests to confirm the diagnosis of hypothyroidism and to rule out other potential causes of the elevated TSH level 5, 6
• Assessing the patient's symptoms and physical examination findings to determine the severity of the hypothyroidism 4, 7

Treatment of Hypothyroidism

The treatment of hypothyroidism typically involves thyroid hormone replacement therapy with levothyroxine (LT4) 3, 4, 5:

• The initial dose of LT4 is typically low, especially in elderly patients or those with a history of coronary artery disease (CAD) 3, 4, 7
• The dose of LT4 is gradually increased until the patient's TSH level is within the normal range 3, 4, 5
• The patient's TSH level is monitored regularly to ensure that it remains within the normal range 4, 5, 6

Special Considerations

There are several special considerations in the treatment of hypothyroidism:

• Elderly patients may require lower doses of LT4 due to decreased thyroid hormone requirements 7
• Patients with a history of CAD may require careful monitoring of their TSH level and LT4 dose to avoid cardiac complications 3, 4
• Patients with subclinical hypothyroidism (elevated TSH level with normal free T4 and T3 levels) may not require treatment, but should be monitored regularly for signs of hypothyroidism 4