Creatinine Clearance Ratio

CCR: It may be defined as virtual volume of plasma. That is completely clear of ceratinine due to excretion through both the kidney in each minute.
Normal range:
1. Serum creatinine 0.6-1.4 mg/dl
2. Urine creatinine .06-1.4 gm/24 hours.
Indication:
1. Early detection of renal damage
2. Neprotoxic drugs.
Specimen:
1. 24 hours unine creatinine
2. Blood serum creatinine
Preservative:   Concentration HCL 5-10 ml for urine
Method:     Jaffe kinetic method
Reagent name:   Alkaline pick red
Prohibition:    Do not taken extra water
Calculation
                    CCR= UxV ml/min                        SC
U= urine creatinine 
                                                  V= 24 hours urine volume
                                                   SC= Serum creatinine
                       Ux5000/24 hour’s  ml/min
                                 S C
                     =  Ux 5000 mimin                   SC         {24 = hours
   60=min                                                                         24×60=1440 min}
Normal range:
Male:    90-140 ml/min
Female: 70-120 ml/min
Advantage :
1. It does not very day to day.
2. It does not depend up diet.
3. It does not absorb by renal tubeles.
Disadvantage:
1. Method not specific
2. Small amount is secreted by renal tubelas(10%)