Definition
A.Term designated for those patients with nonthyroid illnesses who have abnormal thyroid tests and can be classified into the following categories.
1.Low T3 syndrome (most common).
2.Low T3 and low T4 syndrome.
3.High T4 syndrome.
4.Mixed form in which a combination of abnormalities may be found.
Incidence
A.Euthyroid sick syndrome can affect people of all races.
B.It affects both sexes equally.
C.It occurs in people of any age.
Pathogenesis
A.Almost 90% of the hormones secreted by the thyroid gland are T4 and approximately 10% are T3. Most of T4 is converted into T3 in the peripheral tissues, accounting for 90% of the production of T3. The more physiologically active hormone is T3, which is four times more potent than T4.
B.The most common factor in these conditions is reduced extrathyroidal conversion of T4 to T3.
C.With low T3 syndrome, the FT3 is low and the FT4 is normal.
D.The patient is clinically euthyroid and the leading cause in many circumstances is from systemic illness.
E.The low T3 resolves when the underlying illness clears.
F.The low T3 and low T4 syndrome is usually identified in severely ill patients.
G.The TSH early in the illness may be low or normal.
1.As the illness progresses and recovery ensues, the thyroid-stimulating hormone (TSH) is often above normal.
2.Patients who have severely low T3 and T4 levels generally do not do well; mortality approaches 84%.
3.High T4 syndrome is caused by increased concentrations of thyroid-binding globulin produced in certain liver diseases causing high T4 levels. T4 usually returns to normal within 6 to 8 weeks as the disease stabilizes.
Predisposing Factors
A.Acute or chronic illness.
B.Medications.
C.Other endocrine disorders.
D.Burns.
E.Extreme heat or cold.
F.Starvation.
Subjective Data
A.Common complaints/symptoms.
1.Most often, there are no associated symptoms. Careful history and physical examination will not reveal the typical features of hypothyroidism. Lab values will be abnormal.
2.If there are symptoms, they are specific to each case.
B.Common/typical scenario.
1.Patients are usually symptomatic. The condition is found typically during routine screening for thyroid disease.
C.Family and social history.
1.No relevant family or social history.
D.Review of systems.
1.Negative review of systems.
Physical Examination
A.There are no particular findings for patients with nonthyroidal illness.
B.The examination findings in each patient reflect the characteristics of the nonthyroidal disease.
Diagnostic Tests
A.Total T4.
B.Total T3.
C.TSH.
D.Free T4.
E.Reverse T3.
F.Free T3.
Differential Diagnosis
A.Hashimoto’s thyroiditis.
B.Hyperthyroidism.
C.Hypopituitarism.
D.Hypothyroidism.
E.Thyroid dysfunction induced by amiodarone.
Evaluation and Management Plan
A.General plan.
1.Monitor thyroid levels as needed if patient becomes symptomatic. Refer to healthcare provider.
B.Patient and family teaching.
1.If symptoms of hypothyroidism or hyperthyroidism occur, call your healthcare provider.
C.Pharmacology.
1.There is no evidence to date demonstrating the benefit of thyroid replacement in nonthyroidal illness.
D.Discharge instructions.
1.No clear agreement on treatment exists. Hormone replacement with levothyroxine may not help these patients. Allowing for recovery time of the illness and checking thyroid function weeks after the illness resolves are the best treatment for euthyroid sick patients.
Follow-Up
A.Follow-up with primary care provider after release from the hospital.
B.Refer to endocrinology.
Consultation/Referral
A.Referral to an endocrinologist is recommended for monitoring of thyroid function tests both during and after recovery from nonthyroidal illness.
Bibliography
American Association of Clinical Endocrinologists. (2016). Hyperthyroidism: Information for patients. Retrieved from http://thyroidawareness.com/sites/all/files/hyperthyroidism.pdf
Brenner, Z., & Porsche, R. (2006). Amiodarone-induced thyroid dysfunction. Critical Care Nurse, 26(3), 34–41.
Burch, W. (1994). Endocrinology (3rd ed.). Baltimore, MD: Williams & Wilkins.
Burman, K., Ellahham, S., Fadel, B., Lindsay, J., Ringel, M., & Wartofsky, L. (2000). Hyperthyroid heart disease. Clinical Cardiology, 23(26), 402–408. doi:10.1002/clc.4960230605
Carroll, R., & Matfin, G. (2010). Endocrine and metabolic emergencies: Thyroid storm. Therapeutic Advances in Endocrinology and Metabolism, 1(3), 139–145. doi:10.1177/2042018810382481
Chowdhury, S., Ghosh, S., Mathew, V., Misgar, R., Mukhopadhyay, P., Mukhopadhyay, S., … Roychowdhury, P. (2011). Myxedema coma: A new look into an old crisis. Journal of Thyroid Research, 2011, 1–7. doi:10.4061/2011/493462
Dahlen, R., & Kumrow, D. (2002). Thyroidectomy: Understanding the potential for complications. MEDSURG Nursing, 11(5), 228–235.
Francis, J., & Jayaprasad, N. (2005). Atrial fibrillation and hyperthyroidism. Indian Pacing and Electrophysiology Journal, 5(4), 305–311.
Holcomb, S. (2002). Thyroid diseases: A primer for the critical care nurse. Dimensions of Critical Care Nursing, 21(4), 127–133. doi:10.1097/00003465-200207000-00003
Lee, S. (2018, March 15). Hyperthyroidism and thyrotoxicosis. In R. Khardori (Ed.), Medscape. Retrieved from http://emedicine.medscape.com/article/121865-overview
Manzullo, E. F., & Ross, D. S. (2019, February 26). Nonthyroid surgery in the patient with thyroid disease. In J. E. Mulder (Ed.), UpToDate. Retrieved from https://www.uptodate.com/contents/nonthyroid-surgery-in-the-patient-with-thyroid-disease
Merrill, E. (2013). A devastating storm. The Medicine Forum, 14(12), 24–25. doi:10.29046/TMF.014.1.012
The Nurse Practitioner: The American Journal of Primary Healthcare. (2005). Thyroid Disorders, 30(6), 51–52.
Roman, S. (2017). Current best practices in the management of thyroid nodules and cancer. (PowerPoint slides). Retrieved from https://reachmd.com/programs/cme/current-best-practices-in-the-management-of-thyroid-nodules-and-cancer/8470/transcript/16717/
Ross, D. (2018, September 27). Thyroid function in nonthyroidal illness. In J. E. Mulder (Ed.), UpToDate. Retrieved from https://www.uptodate.com/contents/thyroid-function-in-nonthyroidal-illness
Ross, D., & Sugg, S. (2018, September 25). Surgical management of hyperthyroidism. In J. E. Mulder (Ed.), UpToDate. Retrieved from https://www.uptodate.com/contents/surgical-management-of-hyperthyroidism
Tuttle, R. (2018, January 17). Differentiated thyroid cancer: Clinicopathologic staging. In J. E. Mulder (Ed.), UpToDate. Retrieved from https://www.uptodate.com/contents/differentiated-thyroid-cancer-clinicopathologic-staging/print
Umpierrez, G. (2002). Euthyroid sick syndrome. Southern Medical Journal, 95(5), 506–513. doi:10.1097/00007611-200295050-00007