Samples collected in a GTT or RTT must be removed from cells within one hour for storage or transport. Samples collected in gel barrier tubes must be removed from the primary tube prior to transporting to Marshfield. Do not send the primary collection tube.
i-Stat: Sample must be tested within 10 minutes of collection.
Estimated glomerular filtration rate in mL/min/1.73m² is based on age, gender, and creatinine for patients in age range from 18-80 years. Formula assumes Caucasian ethnicity. For Afro-Americans, manually multiply result by 1.21. Formula used is the Simplified MDRD (Modification of Diet in Renal Disease) 4 parameter IDMS equation for Adults, recommended by the NKDEP. GFR = 175 x (creat^ -1.154) x (Age ^ -0.203) x 0.742 (if female)
Hydroxyurea (Hydrea®, Droxia®) may cause significant errors in the measurement of creatinine with the i-STAT System. For every 100 µmol/L hydroxyurea in the whole blood sample, creatinine will be increased by approximately 1.85 mg/dL. Recommended to use an alternative method (e.g the modified jaffe reaction in the main laboratory) to measure creatinine in patients on hydroxyurea.
0 - 3 yrs.: 0.3 - 0.6 mg/dL4 - 13 yrs.: 0.4 - 0.8 mg/dL Male >=14 yrs.: 0.6 - 1.3 mg/dL Female >=14 yrs.: 0.5 - 1.1 mg/dLCalculated GFR (eGFR): >60 mL/min