Disclaimer to the On-line Edition
This Manual has been designed for use in the NICU at London Health Sciences Centre (LHSC), London, Ontario, Canada, and represents clinical practice at this institution. The information contained within the Manual may not be applicable to other centres. If users of this Manual are not familiar with a drug, it is recommended that the official monograph be consulted before it is prescribed and administered. Any user of this information is advised that the contributors, Editor and LHSC are not responsible for any errors or omissions, and / or any consequences arising from the use of the information in this Manual.
Last Uploaded: Thursday, 26-May-2011 00:53:30 EDT
- treatment of symptomatic hypocalcemia (symptoms of hypocalcemia include jitteriness, irritability, convulsions)
- improvement of myocardial contractions
- most of the body's calcium (99%) is in the skeleton. In the blood calcium is present in 3 different forms:
- ~ 40% is bound to albumin
- ~ 10% is complexed with citrate and phosphate
- ~ 50% is ionized calcium (Ca +2)
- ionized calcium (Ca +2) is the physiologically active species.
Parathyroid hormone (PTH) stimulates calcium reabsorption in the distal tubule of the kidney; active
- vitamin D metabolites stimulate calcium reabsorption in the proximal tubule.
- calcitonin inhibits proximal tubular reabsorption of calcium
- calcium contributes to maintaining normal myocardial contractility and normal vascular tone.
- calcium is also involved in the metabolic processes in cells outside the cardiovascular system including the adrenal medulla (release of catecholamines), the neuromuscular system and the CNS
- early hypocalcemia may be seen in infants with true hypoparathyroidism (Di George's syndrome)
- during cardiac resuscitation calcium may be beneficial in restoring normal sinus rhythm and enhancing the efficacy of cardiac electrical defibrillation
- bradycardia can occur if injected too rapidly, overdose can cause cardiac arrest; also shown to cause hypotension and dysrhythmias
- incompatible with many drugs but especially sodium bicarbonate (because of precipitation); consult Pharmacy for compatibility with other drugs
- Avoid extravasation: for calcium burns consider using hyaluronidase
- normal serum calcium (total calcium) values are as follows:
- normal serum calcium (ionized) value for newborns is 1.00 - 1.18 mmol/L
- CONTINUOUS INFUSION MAINTENANCE THERAPY:
|Dose: 0.025 to 0.045 mmol Ca/kg/h|
(Increase dose in refractory hypocalcemia)
The following is a new, simplified method to prepare a calcium supplementation. Instead of preparing a separate infusion, Ca gluconate is added to the maintenance infusion. Generally only two concentrations are necessary: one for maintenance and the other for replacement. The resulting solution is run at the rate necessary to maintain the ordered TFI.
|Add 5mL of 10% calcium gluconate to 95mL of IV solution||= 0.012 mmol Ca / mL|
| ||= 12 mmol Ca / L|
(This concentration is the same as that currently supplied in most TPN solutions.)
|This solution replaces the maintenance solution and is run at the rate necessary to maintain the TFI at the desired amount.|
|At 50 mL/kg/day the amount infused||=||0.025 mmol Ca/kg/h|
|At 100 mL/kg/day the amount infused||=||0.050 mmol Ca/kg/h|
The ordered TFI may be higher. Some of the TFI may be supplied by other infusions (eg. arterial line, inotropes, antibiotics, etc.)
In refractory cases hypocalcemia, or where the maintenance solution is running at a very low rate, the amount of calcium gluconate added to the solution may be higher. The absence of phosphate in the solution allows for higher concentrations of Ca without precipitation occurring.
|Add 10mL of 10% calcium gluconate to 90mL of IV solution||=||0.024 mmol Ca/mL|
| ||=||24 mmol Ca/L|
- CARDIAC ARREST, HYPERKALEMIA, ARRHYTHMIA:
- IV push by a physician or CNS (may be given by a certified RN under a physician's supervision)
- Dilute 10% solution with equal parts of sterile water to make a 5% solution
- 0.6 mL/kg of a 5% solution every 10 to 15 minutes
|10% calcium gluconate (each mL provides 0.48 mEq=0.24 mmol=9.6 mg Ca)
- Roberts, RJ: Drug Therapy in Infants, W.B. Saunders, Toronto, 1984.
- Pagliaro LA and Pagliaro AM (ed): Problems in Pediatric Drug Therapy, 1987, Drug Intelligence Publ Inc, Hamilton, Illinois.
- Parenteral Drug Administration Guidelines, St. Joseph's Health Centre, London, Ontario.
- Gomella TL (Ed): Neonatology - Management, Procedures, On-Call Problems, Diseases, Drugs, 1992, Appleton and Lange, Norwalk, Connecticut.
- Green MG(ed): The Harriet Lane Handbook, 12th edition, 1991 Mosby Year Book, St. Lois, MO.
Updated: 26 February 2001