Physical compatibility of neonatal total parenteral nutrition admixtures containing organic calcium and inorganic phosphate salts in a simulated infusion at 37 degrees C.
OBJECTIVE
Within an incubator environment at 37 degrees C, we evaluated the physical compatibility of calcium (Ca) and phosphate (P) in simulated neonatal total parenteral nutrition (TPN) infusions.


METHODS
Representative neonatal TPN formulas containing four concentrations of amino acids [AA] (1-4 g/dL) and two levels of dextrose [D] (5 and 10 g/dL) were monitored for calcium-phosphate precipitate formation over 24 hours using a laser-based particle counting technique.


METHODS
Research Laboratory.


METHODS
None.


RESULTS
Of the eight AA-D combinations studied, two formulas containing 1 g/dL AA with either 5 g/dL or 10 g/dL of D and high amounts of Ca and P resulted in significant increases in particle counts and visibly evident precipitation during the 24-hour infusion. Precipitation was noted only after the infusion passed through the incubator, but not in the TPN bags, demonstrating the heightened risk of calcium-phosphate incompatibility with increased temperatures.


CONCLUSIONS
Low AA concentrations and high temperatures are significant risk factors for the precipitation of the insoluble dibasic calcium phosphate that may be fatal upon intravenous infusion. When thermoregulation is required, the AA concentration of the TPN formula should not be less than 1.5 g/dL (and ideally > or =3 g/dL) when high intakes of calcium (60 mg/dL) and phosphate (46.5 mg/dL) are prescribed.
Singh
Hardeep
H
Massachusetts College of Pharmacy and Health Sciences, Boston, MA, USA.
Dumas
Gregory J
GJ
Silvestri
Anthony P
AP
Young
Susan
S
Martin
Camilia R
CR
Bistrian
Bruce R
BR
Driscoll
David F
DF
D000596:Amino Acids / Q000032:analysis / Q000737:chemistry; D002118:Calcium / Q000032:analysis* / Q000737:chemistry; D011232:Chemical Precipitation; D006801:Humans; D007231:Infant, Newborn; D010289:Parenteral Nutrition, Total; D010316:Particle Size; D010710:Phosphates / Q000032:analysis* / Q000737:chemistry; D013696:Temperature
D000596:Amino Acids; D010710:Phosphates; D002118:Calcium