Why she developed hypocalcemia?
25 years old lady presented in OPD with the chief complaints of fever, cough, cold and chest pain since 3 days during physical examination there was presents of crackles in the right middle lobe of the lung .X-ray was done x-ray shows consolidation on right middle lobe of the lung. She was diagnosed as lobar pneumonia and discharge with giving antibiotic. After 1 hour she again presented in Emergency with hyperventilation and carpopedal spasm, on physical examination chvostek sign and Trousseau sign is positive she was managed under hypocalcaemia with giving calcium gluconate. Lab test shows decrease free calcium .she doesn’t have any past history of hypocalcaemia. So my question is why she developed hypocalcaemia?
No related posts.
Filed Under: Discussion
this can be due to the clinical phenomenon called syndrome of inappropriate antidiuretic hormane(SIADH). which is most commonly assiciated with the lobar pneumonia. this can occour because the body may retain more water to plasma solutes.
thanks drcook for your reply
could you explain , how SIADH decrease calcium level.
The normal function of ADH on the kidneys is to control the amount of water reabsorbed by kidney nephrons. ADH acts in the distal portion of the renal tubule (Distal Convoluted Tubule) as well as on the collecting duct and causes the retention of water, but not solute. Hence, ADH activity effectively dilutes the blood (decreasing the concentrations of solutes such as sodium).
ADH is secreted to prevent water loss in the kidneys. When water is ingested, it is taken up into the circulation and results in a dilution of the plasma. This dilution, otherwise described as a reduction in plasma osmolality, is detected by osmoreceptors in the hypothalamus of the brain and these then switch off the release of ADH. The decreasing concentration of ADH effectively inhibits the aquaporins in the collecting ducts and distal convoluted tubules in the nephrons of the kidney. Hence, less water is reabsorbed, thereby increasing urine output, decreasing urine osmolality, and normalizing blood osmolality.
In SIADH the release of ADH is not inhibited by a reduction in plasma osmolality when the individual ingests water and the osmolality of the plasma drops. As the main solute of plasma is sodium, this hypoosmolar state is usually detected as a low sodium level on laboratory testing. SIADH is therefore primarily a condition that results in the abnormal handling of water loading and not a problem with excessive solute loss. This is why it is usually treated with fluid (in particular water) restriction. Diuretics may also be given to decrease reabsorption of water, but care must be taken not to correct water imbalances too rapidly
This causes the decrease calcium leavel ..
thanks again drcook
but i think your explanation told us , how there is a hyponateremia in SIADH .
tht might be due to hyperventilation…….coz due to hyperventilation there is hypocarbia…which cause decrease level of ionised calcium n phosphate…so there is decrease in calcium level due to hypocarbia n c develop carpopedal spasm…further cld b better…
thanx dr
Well I agree with Dr Manik… Hyperventilation is the thing here which is causing hypocalcaemia… Hyperventilation leads to respiratory alkalosis which decrease the ionized calcium (normal total calcium level) causing symptoms of hypocalcaemia…
thanks dr makin and drraddr….
i agreed …but i want to add i little
as you guys said that alkalosis decrease the free calcium buz alkalosis increases the binding capacity betn albumin and free calcium.so why there is decrease free calcium but normal total calcium…..
as u knw calcium exist in 2 frm bound n free n there is equilibrium
Total calcium=albumin bound +free form
so by this means free frm is just bind with albumin n decrease free frm but total calcium remains same…isnt it?????
yes absolutely…..there is only decrease in free calcium level but total calcium level remains normal
problem solved…case is closed
i fully agree with you guys,but i want to know why there is hyperventilation in lobar pneumonia and why respiratory alkalosis increases the binding capacity between albumin and free calcium?
in lobar pneumonia, part of the lung is not working so there is tachypnea in order to compensate the loss….and the binding capacity of the albumin and calcium is ph dependent. as pH increases, the binding capacity increases which is seen in respiratory alkalosis…i think..
in lobar pneumonia there is shunting of blood through the affected lobe without any effective ventilation; so,hypoxia develops. this hypoxia gives rise to stimulation of central and peripheral chemoreceptors and thus hyperventilation develops. hyperventilation again causes washing out of CO2-this leads to respiratory alkalosis. Alkalosis causes ionized calcium to become non-ionized, which results in relative deficiency of calcium and associated symptoms and signs.
thanks saurabh .very good explanation 。
i think its good information for me..
i recently became restless had shortnes o breath palpitation,ihad da feeling dat id faint nytime n die, n went to emrgncy n on reaching there i felt my palpitation geting worse n my arm strtd tightning n then my chest my head face till my stomach n den my fist strtd twisting like her. Dr said i had carpopaedal spasm n said they admnstrd calcum inj. With iv n it slowly became ok. I was well bfore da restlessnes n was lying in bed i prespired abit n then strtd bcoming restless. Aftr abt a month i again had da same feeling s i was coming home. Took calcum tblet n propfanolol tblet restd in bed bt it did nt help so i wnt to emrgncy agn, on reaching it got worse agn, i was gvn iv n was feeling week didnt feel like talking too. Few min ltr my arm strtd tightning agn n i told da dr abt it n wt follows aftr it n they hv me calmpose n it subsided, dis time i did nt haf da spasm xcpt my arm strtd to tighten, i guess withot da inj i would hafhad da spasm. Doc said i had swollen intestine n infection in it. Bt did nt prescrbe any further imvestigation xcept for blood test. Can any one advice me wt my problem may be? I take alcohol. They told me i was allergic to it bt i haf taken it for years n neve had any problem wtsoever. Please advise
Mr.tyke .
u had the recurrent carpopaedel spasm that mean u have hypocalcemia（ Low serum calcium level in the body) which indicate that u have some problem of your parathyroid gland, so i advice to consult the endocrinologist. Some time infection of the body also cause the hypocalcemia. .Alcohol didn’t cause swollen intestine but make your symptoms worse . Ultrasound or CT scan is needed to detect the swollen intestine only blood test cant detect the swollen stomach , blood test only confirm the infection …I think CT scan or Ultrasound may be needed for u to confirm the diagnosis . I think u get the answer any question dont hesitate to write