LOINC display name : Hydroxyapatite (24H U) [Energy diff];
LOINC long common name : Hydroxyapatite [Energy Difference] in 24 hour Urine;
LOINC short name : Hydroxyapatite 24h EngDiff Ur;
LOINC description : Supersaturation of urine correlates with stone type. Measurement of supersaturated
urine can be used for the diagnosis and management of patients with renal lithiasis,
in patients who have a radiopaque stone, or when stone analysis is not possible. The
supersaturation can be used to predict the likely composition. Urine supersaturation
changes can also be used to monitor the effectiveness of therapy by confirming that
the crystallization potential is been decreased. The differential Gibbs free energy
is a measure of the thermodynamic pressure for crystals to form. For this term, a
software program, EQUIL [PMID: 3840540] was used to calculate the urinary supersaturation
for the common kidney stone components expressed as the Gibbs free energy of transfer
from a supersaturated to a saturated solution. The delta G (DG) will equal zero for
solutions at saturation, will be greater than zero for super-saturated solutions,
and less than zero for under-saturated solutions. Positive values above the reference
mean are associated with increased risk for that type of crystal formation.;
Has component