Case Study, Chapter 41, Disorders of Endocrine Control of Growth and Metabolism
Bertha is a 71-year-old woman who takes daily medication for Hashimoto thyroiditis. Last winter, she developed pneumonia. Although she did her best to run errands for her husband, she got tired easily and needed to rest frequently. One day, after shoveling the snow outside, her husband came inside to find Bertha lying on the sofa covered in blankets. Her face appeared puffy and her eyelids hung. When he spoke to her, Berthas voice was hoarse and her words did not make sense to him. Her respirations were also shallow and slow. Suspecting low thyroid hormone levels were causing the signs, her husband called for an ambulance (Learning Objectives 6 and 7).
1. When testing for hypothyroidism, why is the free T4 level an important measurement? What would the TSH and T4 test results indicate in someone with primary hypothyroidism?
2. Using your knowledge of the function of thyroid hormone in the body, explain why Berthas respiratory rate was decreased? Why might pleural effusion be present in someone with hypothyroidism?
3. What factors in Berthas history leave her susceptible to myxedematous coma? What are the physiologic aspects involved in myxedematous coma?