Hypocalcemia
General
Send child to Emergency Room if total calcium <1.8 mmol/L or > 1.8 and <2.0 with seizures
For most clinical situations, use the total calcium as the true calcium and the ionized for backup purposes. However, if there is an expectation that the albumin level may be low or if there are acid base abnormalities, rely more on the ionized calcium
Whom and when to refer to SickKids Hospital- see below
Definitions:
Our working definition of hypocalcemia is a total calcium less than 2.2mmol/L.. Please note: normal ranges may vary depending on the assay, the laboratory and age of the patient
Severe
Total Calcium level < or equal to 1.8mmol/L and/or Ionized calcium < 0.8mmol/L
Recommendations
Treatment
IV calcium infusion (see Sick Kids Handbook) is often required
Calcitriol 0.1 mcg/kg/day by mouth until calcium returns to normal range then reduce to 0.04mcg/kg/day
Calcium requirement by mouth based on age
Investigations
Blood: serum calcium (total and ionized), phosphate, alkaline phosphatase, creatinine, 25 (OH) Vitamin D, 1, 25 (OH)2 Vitamin D, PTH
Urine (random); calcium/creatinine ratio
X ray L hand
Consultation
Contact endocrine doctor or alternate on call to review treatment and investigations
Referral to Calcium Bone Clinic- see details below
Moderately Severe
Total serum calcium between 1.8mmol/L and 2.0mmol/L
Recommendations
As for Severe Hypocalcemia above
Borderline
Total Calcium between 2.0mmol/L and 2.2mmmol
Recommendation
Confirm with serum and urine investigations above (severe hypocalcemia)
Common causes of Hypocalcemia :
Vitamin D disorders
Hypoparathyroidism (Di George/Q 22 Deletion Syndrome)