Hypocalcemia: Difference between revisions
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==Background== | ==Background== | ||
===Serum Levels=== | ===Serum Levels=== | ||
''Normal value ranges may vary among different laboratories | ''Normal value ranges may vary slightly among different laboratories'' | ||
* | *Low: <8.9 mg/dL<ref>Harbor-UCLA computer system accessed 08/15/2019</ref> (Ionized: <4.8 mg/dL or <1.20 millimol/L<ref>https://www.ucsfhealth.org/tests/003486.html</ref>) | ||
*Critical low: <6.6 mg/dL<ref>Harbor-UCLA computer system accessed 08/15/2019</ref> (Ionized: <3.5 mg/dL<ref>http://www.clinlabnavigator.com/calcium-ionized.html</ref>) | |||
*Critical low: <6.6 (< | |||
*Correct for hypoalbumimia | *Correct for hypoalbumimia | ||
| Line 38: | Line 38: | ||
**[[Norepinephrine]] | **[[Norepinephrine]] | ||
**[[Glucagon]] | **[[Glucagon]] | ||
**Glucocorticoids | **[[Glucocorticoids]] | ||
**Magnesium sulfate | **[[Magnesium sulfate]] | ||
**[[Nitroprusside]] | **[[Nitroprusside]] | ||
==Clinical Features== | ==Clinical Features== | ||
*Paresthesias (mouth, fingertips) | *[[Paresthesias]] (mouth, fingertips) | ||
*↑ DTRs | *↑ DTRs | ||
*Cramps | *Cramps | ||
| Line 53: | Line 53: | ||
*Laryngospasm | *Laryngospasm | ||
*Bronchospasm | *Bronchospasm | ||
*Cardiac dysrhythmias | *Cardiac [[dysrhythmias]] | ||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
| Line 76: | Line 76: | ||
==Management== | ==Management== | ||
''Avoid empiric treatment in patients taking digoxin due to risk for [[Stone Heart]]'' | ''Avoid empiric treatment in patients taking [[digoxin]] due to risk for [[Stone Heart]]'' | ||
*Asymptomatic | *Asymptomatic | ||
**Calcium gluconate 1 gm PO Q6hrs | **[[Calcium gluconate]] 1 gm PO Q6hrs | ||
**Vitamin D (calcitriol) 0.2 mcg BID | **Vitamin D (calcitriol) 0.2 mcg BID | ||
*Symptomatic | *Symptomatic | ||
**Calcium gluconate/chloride 10mL of 10% soln IV over 10min | **[[Calcium gluconate]]/[[calcium chloride|chloride]] 10mL of 10% soln IV over 10min | ||
*Correct [[hypomag]] at same time (otherwise PTH is inhibited) | *Correct [[hypomag]] at same time (otherwise PTH is inhibited) | ||
*Avoid phenothiazine [[antipsychotics]] (may precipitate extrapyramidal symptoms) | *Avoid phenothiazine [[antipsychotics]] (may precipitate extrapyramidal symptoms) | ||
Revision as of 16:06, 29 September 2019
Background
Serum Levels
Normal value ranges may vary slightly among different laboratories
- Low: <8.9 mg/dL[1] (Ionized: <4.8 mg/dL or <1.20 millimol/L[2])
- Critical low: <6.6 mg/dL[3] (Ionized: <3.5 mg/dL[4])
- Correct for hypoalbumimia
- Corrected Ca = (0.8 *(Normal Alb - Patient's Alb)) + Serum Ca
Fraction[5]
- 15% bound to anions (phosphate, lactate, citrate)
- 40% bound to albumin
- 45% free (regulated by PTH, Vit-D)
Causes
- Misc
- Shock
- Sepsis
- Pancreatitis
- Hypomag
- Rhabdo (phosphate overload)
- Massive transfusion
- Systemic Hydrofluoric Acid toxicity
- DiGeorge syndrome
- Decreased absorption
- Increased excretion
- Endocrine
- Drugs
- Cimetidine
- Phenytoin
- Lasix, loop diuretics
- Norepinephrine
- Glucagon
- Glucocorticoids
- Magnesium sulfate
- Nitroprusside
Clinical Features
- Paresthesias (mouth, fingertips)
- ↑ DTRs
- Cramps
- Weakness
- Confusion
- Seizures
- Chvostek/Trousseau signs, Tetany
- Hallucinations
- Laryngospasm
- Bronchospasm
- Cardiac dysrhythmias
Differential Diagnosis
Jaw Spasms
- Acute tetanus
- Akathisia
- Conversion disorder
- Drug toxicity (anticholinergic, phenytoin, valproate, carbamazepine)
- Dystonic reaction
- Electrolyte abnormality
- Hypocalcemic tetany
- Magnesium
- Mandible dislocation
- Meningitis
- Peritonsillar abscess
- Rabies
- Seizure
- Strychnine poisoning
- Stroke
- Temporomandibular disorder
- Torticollis
Evaluation
ECG
- QT Prolongation via increasing the ST length
- Only hypothermia and hypocalcemia prolong QT this way
Trousseau's Sign (Mod to high SN and SP)
- Inflate BP cuff for 2-3 mins
- Positive = Muscle contractions of the hand and wrist
Chvostek's Sign (Low SN and SP)
- Tapping on the face just anterior to the ear and just below the zygomatic bone
- Positive = Ipsilateral facial twitching
Labs
- BMP
- Mag, Phos
- PTH (secondary hyperparathyroidism)
Management
Avoid empiric treatment in patients taking digoxin due to risk for Stone Heart
- Asymptomatic
- Calcium gluconate 1 gm PO Q6hrs
- Vitamin D (calcitriol) 0.2 mcg BID
- Symptomatic
- Calcium gluconate/chloride 10mL of 10% soln IV over 10min
- Correct hypomag at same time (otherwise PTH is inhibited)
- Avoid phenothiazine antipsychotics (may precipitate extrapyramidal symptoms)
- Avoid furosemide (may worsen hypocalcemia)
Disposition
- Admit all symptomatic patients
See Also
References
- ↑ Harbor-UCLA computer system accessed 08/15/2019
- ↑ https://www.ucsfhealth.org/tests/003486.html
- ↑ Harbor-UCLA computer system accessed 08/15/2019
- ↑ http://www.clinlabnavigator.com/calcium-ionized.html
- ↑ Yu, AS. Relation between total and ionized serum calcium concentrations. In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA. (Accessed on October 6th, 2016.)
Video
{{#widget:YouTube|id=6QrzmVYMkWc}}