Urine Electrolytes, Osmolality

2nd AM sample is preferred (more reflective of 24 hour collection) but often use random convenience sample

Normal values:

• • Prem 95%ile <2.4

  • 0-7 months <0.7

  • 8-18 months<0.5

  • <6 years <0.28

  • >6 years <0.2

  • black are a little lower

(Source: Alon Ped Neph 2001;16:133)

References ranges for urine calcium/creatinine ratio:

<6 months of age: <0.8 mg/mg (2.25 mmol/mmol)

6-12 months of age: <0.6 mg/mg (1.7 mmol/mmol)

Children two years of age or older – <0.2 mg calcium/mg creatinine (0.6 mmol/mmol)