Mr. Jessup, a 55-year-old man, is operated on for a cerebral t...

Question

Mr. Jessup, a 55-year-old man, is operated on for a cerebral tumor. About a month later, he appears at his physician's office complaining of excessive thirst. He claims to have been drinking about 20 liters of water daily for the past week and says he has been voiding nearly continuously. A urine sample is collected and its specific gravity is reported as 1.001.
What is your diagnosis of Mr. Jessup's problem?
What connection might exist between his previous surgery and his present problem?

What is your diagnosis of Mr. Jessup's problem?

What connection might exist between his previous surgery and his present problem?

Accepted Answer

Hi, everybody. Let's look at our next problem. It says Mr Harley, a 68 year old Jeep Driver had an accident and underwent cranial surgery a few months after the surgery, he developed symptoms of extreme thirst with increased urination and presented to the Annie Department with dehydration. The on duty doctor gave him oral desmopressin and his condition improved miraculously within a few hours. What do you think Mr Harley is suffering from a central diabetes, citu B, nephrogenic diabetes, incipit C diabetes, meleis or D Addison's disease. Well, first of all, we can just rule out right away to the Addison's disease. A disease is a cortisol deficiency. Cortisol is produced by the adrenal glands and it does not produce symptoms of increased urination and thirst. But all three forms of diabetes do. So, we want to rule out uh the ones or, or choose the one that he is suffering from based on what's the information presented to us. So, one crucial thing to know to solve this problem is what is Desmon Presson. Well, de repression is a synthetic form of vasopressin, otherwise known as a DH or antidiuretic hormone. So this starts to make sense given that the antidiuretic hormone causes increased reabsorption of water. So it would cause less urine to be excreted or less water to be excreted in urine. And we see that he had extreme thirst and increased urination. So his symptoms tell us that too much water is being excreted in his urine. And we know that when he was given a DH, he improved miraculously. So that would indicate that his body is not producing enough or any A BH. And now the key is we see in his personal history that he had cranial surgery. So that indicates that there might have been damage to his hypothalamus or pituitary gland, which are responsible for re secreting A DH that leads us to choice. A central diabetes citi and in central diabetes inhibit in there is a deficiency or lack of production of a DH. And because that uh prevents the kidneys from having better reabsorption of water, it means that too much water may be being excreted in urine causing symptoms of increased urination, extreme thirst. And in the worst case scenario, dehydration. When we look at our other answer choices, choice B is another form of diabetes, Ettus, nephrogenic diabetes, Ettus, but in that case, the kidneys fail to respond. So kidneys don't respond two A H. So you have the same symptoms since the kidneys aren't responding to that signal to reabsorb more water. So too much water gets excreted, but there's plenty of a DH around the kidneys just aren't responding to it. So in that case, the distinguishing factor between being able to tell which this is is the fact that the administration of oral desmopressin caused such improvement. If it were nephrogenic diabetes inhibits adding, throwing an extra A BH by administering this medication wouldn't make any difference because there already is plenty of a bh, the kidneys just aren't responding to it. Finally choice C diabetes meleis is a lack or deficiency of insulin leading to high blood sugar. So that also wouldn't respond to the administration of desmopressin. So that's why that's not a correct answer. Why does the difficulty or deficiency in insulin that causes high blood sugar cause the same symptoms of increased thirst and increased urination? That's because when you have those high glucose levels, some of the glucose is excreted in the urine and the kidneys excrete extra water to dilute the urine. So totally different cause of those symptoms, even though it presents with the same symptoms. So again, we've got our patient who's had prior cranial surgery, symptoms of extreme thirst, increased urination and presenting with dehydration. And he has this rapid improvement when given oral desmopressin. And that would lead us to believe that Mr Harley is suffering from choice, a central diabetes Ettus see you in the next video.

Key Concepts

Diabetes Insipidus

Role of the Hypothalamus and Pituitary Gland in Water Balance

Urine Specific Gravity and Its Clinical Significance

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