Hypocalcemia

Definition/Description[1][2]

Hypocalcemia, a low bood calcium level, occurs when the concentration of free calcium ions in the blood falls below 4.4 mg/dL. The normal concentration of free calcium ions in the blood serum is 4.4-5.4 mg/dL.

Prevalence [3]

Incidence and prevalence are difficult to estimate because hypocalcemia is a multifactorial diagnosis. Postsurgical hypoparathyroidism is decreasing as thyroid and parathyroid surgery techniques improve. 

Decreases in total serum calcium are quite common in ill patients, but ionized calcium typically remains normal.

Characteristics/Clinical Presentation[2]

In neonates, hypocalcemia is more likely to occur in infants born of diabetic or preeclamptic mothers. Hypocalcemia also may occur in infants born to mothers with hyperparathyroidism.  Clinically evident hypocalcemia generally presents in milder forms and is usually the result of a chronic disease state. In emergency department patients, chronic or subacute complaints secondary to mild or moderate hypocalcemia are more likely to be a chief complaint than severe symptomatic hypocalcemia.  In an elderly patient, a nutritional deficiency may be associated with a low intake of vitamin D. A history of alcoholism can help diagnose hypocalcemia due to magnesium deficiency, malabsorption, or chronic pancreatitis.  Acute hypocalcemia may lead to syncope, congestive heart failure, and angina due to the multiple cardiovascular effects.  Neuromuscular and neurologic symptoms may also occur.
Neuromuscular symptoms include the following:

  • Numbness and tingling sensations in the perioral area or in the fingers and toes
  • Muscle cramps, particularly in the back and lower extremities; may progress to carpopedal spasm (ie, tetany)
  • Wheezing; may develop from bronchospasm
  • Dysphagia
  • Voice changes (due to laryngospasm)

Neurologic symptoms of hypocalcemia include the following:

  • Irritability, impaired intellectual capacity, depression, and personality changes
  • Fatigue
  • Seizures (eg, grand mal, petit mal, focal)
  • Other uncontrolled movements

Chronic hypocalcemia may produce the following dermatologic manifestations:

  • Coarse hair
  • Brittle nails
  • Psoriasis
  • Dry skin
  • Chronic pruritus
  • Poor dentition
  • Cataracts

Associated Co-morbidities [3]

  • Epilepsy (in adults or in children): hypocalcemia secondary to anticonvulsant therapy
  • HIV: hypocalcemia due to calcium chelation in foscarnet therapy
  • Chronic liver disease: defective hydroxylation of vitamin D
  • Intestinal malabsorption
  • Tuberculosis: isoniazid therapy

Medications [2]

  • Calcium chloride
  • Calcium Gluconate
  • Calcium carbonate
  • Calcium citrate
  • Calcitrol
  • Vitamin D

Diagnostic Tests/Lab Tests/Lab Values [2][3]

Acute hypocalcemia causes prolongation of the QT interval, which may lead to ventricular dysrhythmias (see the image below). [2]

EKG.jpg
                                                                                                                                [2]

Hypocalcemia needs confirmation, if there is any doubt, by measurement of the serum ionized calcium level. When the diagnosis is confirmed by the finding of a serum calcium level lower than 8.2 mg/dL (2.05 mmol/L) or an ionized calcium level lower than 4.4 mg/dL (1.1 mmol/L), attention should turn toward seeking the cause.[3]


  • Serum calcium levels less than 8.2 mg/dL or ionized calcium levels less than 4.4 mg/dL.*

Etiology/Causes [2]

The causes of hypocalcemia include the following:

  • Hypoalbuminemia
  • Hypomagnesemia
  • Hyperphosphatemia
  • Multifactorial enhanced protein binding and anion chelation
  • Medication effects
  • Surgical effects
  • PTH deficiency or resistance
  • Vitamin D deficiency or resistance


Patients with burns & renal dysfunction may be at risk for this disorder

Systemic Involvement [2]

Acute hypocalcemia may lead to syncope, congestive heart failure (CHF), and angina due to the multiple cardiovascular effects. Neuromuscular and neurologic symptoms may also occur.

Neuromuscular symptoms include the following:

Numbness and tingling sensations in the perioral area or in the fingers and toes
Muscle cramps, particularly in the back and lower extremities; may progress to carpopedal spasm (ie, tetany)
Wheezing; may develop from bronchospasm
Dysphagia
Voice changes (due to laryngospasm)

Neurologic symptoms of hypocalcemia include the following:

Irritability, impaired intellectual capacity, depression, and personality changes
Fatigue
Seizures (eg, grand mal, petit mal, focal)
Other uncontrolled movements

Chronic hypocalcemia may produce the following dermatologic manifestations:

Coarse hair
Brittle nails
Psoriasis
Dry skin
Chronic pruritus
Poor dentition
Cataracts

Medical Management (current best evidence) [2]

Most hypocalcemic emergencies are mild and require only supportive treatment and further laboratory evaluation. On occasion, severe hypocalcemia may result in seizures, tetany, refractory hypotension, or arrhythmias that require a more aggressive approach.
In the emergency department, magnesium and calcium (in their many different forms) are the only medications necessary to treat hypocalcemic emergencies. The consulting endocrinologist may choose to prescribe any of the various vitamin D supplements depending on laboratory workup findings, and oral calcium supplementation for outpatient therapy.

Physical Therapy Management (current best evidence)

Due to the nature of hypocalcemia being secondary to a primary disease state, physical therapy management includes recognition of the signs and symptoms thereof. Appropriate action taken and appropriate referral.

Differential Diagnosis [2]

  • Acute Renal Failure
  • Hydrofluoric Acid Burns
  • Hyperparathyroidism
  • Hyperphosphatemia
  • Hypoalbuminemia
  • Hypomagnesemia
  • Hypoparathyroidism
  • Metabolic Alkalosis
  • Pancreatitis, Acute

Case Reports/ Case Studies

  1. Shulman R, O'gorman CS, Sochett EB. Case 1: Neonate with seizures and hypocalcemia. Paediatr Child Health. 2008;13(3):197-200. www.ncbi.nlm.nih.gov/pmc/articles/PMC2529411/
  2. Dawrant J, Pacaud D. Pediatric hypocalcemia: making the diagnosis. CMAJ. 2007;177(12):1494-7. www.ncbi.nlm.nih.gov/pmc/articles/PMC2096479/
  3. Fong J, Khan A. Hypocalcemia: updates in diagnosis and management for primary care. Can Fam Physician. 2012;58(2):158-62. www.cfp.ca/content/58/2/158.full


Resources

http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/endocrinology/hypocalcemia/

https://www.clinicalkey.com/topics/endocrinology/hypocalcemia.html

http://emedicine.medscape.com/article/241893-overview

http://www.healthaliciousness.com

http://www.webmd.com/diet/vitamin-d-deficiency

Recent Related Research (from Pubmed)



References

  1. The Medical Dictionary. Available at http://medical-dictionary.thefreedictionary.com/hypocalcemia. Accessed on 2013 April 7
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 Medscape Reference. Hypocalcemia. Available at http://emedicine.medscape.com/article/241893-overview. Accessed 2013 April 7.
  3. 3.0 3.1 3.2 3.3 ClinicalKey. Hypocalcemia. Available at https://www.clinicalkey.com/topics/endocrinology/hypocalcemia.html. Accessed 2013 April 7

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