#june2020amc1
A 60-year-old man with acromegaly undergoes a trans-sphenoidal procedure to resect a pituitary adenoma. 48 hours post-operatively he develops severe thirst, and passes volumes of urine exceeding 5 litres/24h. His sodium level is 166 mmol/l. What is the most likely explanation for these symptoms?
A. Cerebral salt wasting syndrome
B. Diabetes insipidus
C. Hypoadrenalism
D. Overload of intravenous fluids in the peri-operative period
E. Syndrome of inappropriate antidiuretic hormone secretion
Explanatory Notes:
Loss of vasopressin is the cause. Desmopressin is the pharmacological structural analogue. All other distractors are involved in sodium homeostasis. Demeclocycline is used in treatment of SIADH - not in DI.
There are 2 types of diabetes insipidus: cranial diabetes insipidus (CDI) and nephrogenic diabetes insipidus (NDI). CDI is caused by a lack of ADH, which means that the kidneys cannot retain water, resulting in extreme thirst.
NDI is a condition in which the kidneys do not respond to normal levels of ADH.The primary symptoms of NDI are polyuria and polydipsia.
In this case, surgery to remove the tumour has caused a dramatic acute reduction in ADH.
A 60-year-old man with acromegaly undergoes a trans-sphenoidal procedure to resect a pituitary adenoma. 48 hours post-operatively he develops severe thirst, and passes volumes of urine exceeding 5 litres/24h. His sodium level is 166 mmol/l. What is the most likely explanation for these symptoms?
A. Cerebral salt wasting syndrome
B. Diabetes insipidus
C. Hypoadrenalism
D. Overload of intravenous fluids in the peri-operative period
E. Syndrome of inappropriate antidiuretic hormone secretion
Explanatory Notes:
Loss of vasopressin is the cause. Desmopressin is the pharmacological structural analogue. All other distractors are involved in sodium homeostasis. Demeclocycline is used in treatment of SIADH - not in DI.
There are 2 types of diabetes insipidus: cranial diabetes insipidus (CDI) and nephrogenic diabetes insipidus (NDI). CDI is caused by a lack of ADH, which means that the kidneys cannot retain water, resulting in extreme thirst.
NDI is a condition in which the kidneys do not respond to normal levels of ADH.The primary symptoms of NDI are polyuria and polydipsia.
In this case, surgery to remove the tumour has caused a dramatic acute reduction in ADH.
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