WBR0213

Author	PageAuthor::Vendhan Ramanujam
Exam Type	ExamType::USMLE Step 2 CK
Main Category	MainCategory::Internal medicine
Sub Category	SubCategory::Endocrine, SubCategory::Endocrine
Prompt	[[Prompt::A 56 year old diabetic male is admitted to the coronary care unit with acute myocardial infarction complicated by cardiogenic shock. His hospital course was complicated by acute renal failure. His thyroid study came out as abnormal. He does not have any previous history of thyroid disease. Physical examination of the thyroid gland is found to be normal. Lab result of the thyroid study is as follows: Serum T3: 1.1 nmol/L (Normal 1.8 to 2.9 nmol/L) Serum T4: 8 microg/dL (Normal 5 to 12 microg/dL) The most likely diagnosis is]]
Answer A	AnswerA::Primary hypothyroidism
Answer A Explanation	[[AnswerAExp::Incorrect-Decreased total and free T4 with increased TSH level is seen in primary hypothyroidism.]]
Answer B	AnswerB::Central hypothyroidism
Answer B Explanation	AnswerBExp::'''Incorrect'''-Low T4 with normal TSH level can be seen in central hypothyroidism.
Answer C	AnswerC::Subclinical hypothyroidism
Answer C Explanation	AnswerCExp::'''Incorrect'''-Normal T3 and T4 with increased TSH level is seen in subclinical hypothyroidism.
Answer D	AnswerD::Sick euthyroid syndrome
Answer D Explanation	[[AnswerDExp::Correct-Any patient with acute and severe illness may have an abnormal thyroid function test. This is sick euthyroid syndrome (low T3 syndrome), which is due to the caloric deprivation and increased cytokine levels during the period of illness. The abnormality pattern is usually a low total or free T3 level with normal T4 and TSH levels, due to decrease in the peripheral conversion of T4 to T3. Longer the duration of illness, T3 fall might be followed by fall in T4 and TSH levels. On recovery from illness there might be a transient increase in TSH levels. For this reason, a thyroid test is usually not performed in severely ill patients unless there is a strong indication, since these abnormalities can be misleading.]]
Answer E	AnswerE::Reidels thyroiditis
Answer E Explanation	AnswerEExp::'''Incorrect'''-Reidels thyroiditis presents as primary hypothyroidism.
Right Answer	RightAnswer::D
Explanation	[[Explanation::Any patient with acute and severe illness may have an abnormal thyroid function test. This is sick-euthyroid syndrome (low T3 syndrome), which is due to the caloric deprivation and increased cytokine levels during the period of illness. The abnormality pattern is usually a low total or free T3 level with normal T4 and TSH levels, due to decrease in the peripheral conversion of T4 to T3. Longer the duration of illness, T3 fall might be followed by fall in T4 and TSH levels. On recovery from illness there might be a transient increase in TSH levels. For this reason, a thyroid test is usually not performed in severely ill patients unless there is a strong indication, since these abnormalities can be misleading. Educational objective: Any acute and severely ill patient might have an abnormal thyroid function test. This is called sick euthyroid syndrome (low T3 syndrome) with a low T3 and normal T4, TSH levels, the most common abnormal pattern. Educational Objective: References: ]]
Approved	Approved::Yes
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