PAH clearance
| Parameter | Value |
|---|---|
| renal blood flow | RBF=1000 ml/min |
| hematocrit | HCT=40% |
| renal plasma flow | RPF=600 ml/min |
| filtration fraction | FF=20% |
| glomerular filtration rate | GFR=120 ml/min |
| urine flow rate | V=1 mL/min |
| Sodium | Inulin | Creatinine | PAH |
|---|---|---|---|
| SNa=150 mEq/L | SIn=1 mg/mL | SCr=0.01 mg/ml | SPAH= |
| UNa=710 mEq/L | UIn=150 mg/mL | UCr=1.25 mg/mL | UPAH= |
| CNa=5 mL/min | CIn=150 ml/min | CCr=125 mL/min | CPAH=420 ml/min |
| ER=90% | |||
| ERPF=540 ml/min |
Para-aminohippurate (PAH) clearance is a method used in renal physiology to measure renal plasma flow, which is a measure of renal function.
The concentration of PAH is measured in one arterial blood sample (PPAH) and one urine sample(UPAH). The urine flow (V) is also measured. Renal perfusion flow is then calculated by:
What is calculated is the effective renal plasma flow (eRPF). However, since the renal extraction ratio of PAH almost equals 1, then eRPF almost equals RPF.
Precision
The renal extraction ratio of PAH in a normal individual is approximately 0.92,[1] and thus not exactly 1.0. Thus, this method usually underestimates RPF by approximately 10%. This margin of error is generally acceptable considering the ease with which eRPF is measured.
See also
References
- ↑ Reubi FC (September 1953). "Glomerular filtration rate, renal blood flow and blood viscosity during and after diabetic coma" (PDF). Circulation Res. 1 (5): 410–3. PMID 13082682.
External links
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