DrAlex_76
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A 55 yo man homeless, come to Er with c/c of muscle cramps and perioral numbing. Pt looks malnourished, drinks a lot of alcohol. PE shows T = 36.7 , BP = 110/65, Hb = 7.2, MCV = 105, Ca = 6.8 mg/dl What is the most probable cause of hypocalcemia in this pt ?
A. Renal failure
B. Primary hypoparathyroid
C. Pseudohypoparathyroid
D. Hypoalbuminemia
E. Malabsorption
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| kpmle2
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D. Hypoalbuminemia
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| DrAlex_76
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why not E ? this pt has hypocalcemia symptom, means that her ionized Ca is low
Low protein causes low Ca bound protein which does not cause the symptoms.
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| Eagle_303
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It seems to be a case of primary hypoparathyroid.
Alcohol very common cause of Hypomagnesemia --------------> Functional hypoparathyroid ----------> Hypocalcemia --------------> tetany
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| nightflight1945
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E. Malabsorption
Alcohol can cause chronic pancreatitis and this can account for pancreatic enzyme deficiency and fat malabsorption which binds Ca and cause calcium malabsorption.
hypoalbuminemia cannot be the cause , because as Dr.Alex mentioned first it doesnot cause symptoms and also even if he has Albumin of 2 that will correct Ca for 6.8+2*0.8=8.4 that is still low.(Alb =2 is very low and belongs to nephrotic patients or cirrhotic)
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| Eagle_303
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nightflight1945 wrote:
E. Malabsorption
Alcohol can cause chronic pancreatitis and this can account for pancreatic enzyme deficiency and fat malabsorption which binds Ca and cause calcium malabsorption.
hypoalbuminemia cannot be the cause , because as Dr.Alex mentioned first it doesnot cause symptoms and also even if he has Albumin of 2 that will correct Ca for 6.8+2*0.8=8.4 that is still low.(Alb =2 is very low and belongs to nephrotic patients or cirrhotic)
My dear friend from where you are getting serum albumin of this patient? The stem question in front of me does not show it .
Secondly Serum Albumin 2 without generalized edema ,looks very strange.
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| nightflight1945
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Eagle_303 wrote:nightflight1945 wrote:
E. Malabsorption
Alcohol can cause chronic pancreatitis and this can account for pancreatic enzyme deficiency and fat malabsorption which binds Ca and cause calcium malabsorption.
hypoalbuminemia cannot be the cause , because as Dr.Alex mentioned first it doesnot cause symptoms and also even if he has Albumin of 2 that will correct Ca for 6.8+2*0.8=8.4 that is still low.(Alb =2 is very low and belongs to nephrotic patients or cirrhotic)
My dear friend from where you are getting serum albumin of this patient? The stem question in front of me does not show it . Secondly Serum Albumin 2 without generalized edema ,looks very strange.
So , it was just an example to rule out low albumin as the cause.You accept that his albumin is higher than 2 , (I proved even with alb=2 it cannot be the cause).
the reason is malabsorption.
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| DrAlex_76
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good discussion ! 
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| Eagle_303
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As long as Ca in the bone (storage house) is available and Parathyroid gland is working normally ,Hypocalemia (ionized form) should not occur because of malnutrition albeit at the cost of bone health.
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| nightflight1945
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Eagle_303 wrote:
As long as Ca in the bone (storage house) is available and Parathyroid gland is working normally ,Hypocalemia (ionized form) should not occur because of malnutrition albeit at the cost of bone health.
So now I'v learned sth really new.So the only cause of hypocalcemia is hypoparathyroidism and we don't have any other cause. I'm really disappointed now , because in med-school it took me a lot of time to study the reasons for hypocalcemia,
Have you ever heard about tetany or seizure in a child with rickets/osteomalacia and normal hypothyroid function???
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| Eagle_303
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Rickets ,osteomalacia and malnutritions can cause tetany as the body Ca store is inadequate.
Analogy is with Glycogen .As long as glycogen store is there and its breakdown mechanism is intact ,No hypoglycemia.But once glycogen is depleted then hypoglcemia causing factors are apparent.
Same is the case with Ca store.
Most common cause of hypocalemia are two
1 ecrease mobilization of Ca from bone
2:Excessive loss of Ca from the kidney
All rest of other causes come later.
Pt is chronic alcoholic having malnutrition. Mg is very commonly deficient in alcoholics. Hypomagnesemia is must or ;
- Synthesis of PTH
- Release of PTH
- Action of PTH
So Hypomagnesemia ---------------> Functional Hypoparathyroidism ---------------> resistant type of tetany
Just a view ,you may disagree with it.
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| DrAlex_76
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http://www.clevelandclinicmeded.com/medicalpubs/d...
just for fun ...
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| nightflight1945
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When hypopara is causued by Mg deficiency , it is no more called Primary hypoparathyroid.
And how do you know that the patient's Ca storage is adequate?
There is no need to make things complicated , medicine is not that much difficult or confusing that u think.
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| nightflight1945
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Pancreatitis can be associated with tetany and hypocalcemia. It is caused primarily by precipitation of calcium soaps in the abdominal cavity, but glucagon-stimulated calcitonin release and decreased PTH secretion may play a role. When the pancreas is damaged, free fatty acids are generated by the action of pancreatic lipase. Insoluble calcium salts are present in the pancreas, and the free fatty acids avidly chelate the salts, resulting in calcium deposition in the retroperitoneum. In addition, hypoalbuminemia may be a part of the clinical picture, resulting in a reduction in total serum calcium. In patients with concomitant alcohol abuse, a poor nutritional intake of calcium and vitamin D, as well as accompanying hypomagnesemia, may predispose these patients to hypocalcemia.
www.emedicine.com/med/topic1118.htm
Although hypomagnesemia can be the cause , the main cause is malnutrition and also the reason for hypomagnesemia is also malnutrition , and as I said before functional hypopara is different from primary hypopara,
Take it or not , option is yours!
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| ngaybinhyen
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Low magnesium levels from malnutrition of alcoholism prevent the release of parathyroid hormone from the parathyroid glands --> Symptomatic hypocalcemia
Malnutrition
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