[Renal function monitoring using an ambulatory renal monitor]

Diethylenetriamine penta acetic acid (99mTc-DTPA), a substance which indicates glomerular filtration, is distributed equally in blood and tissue after a bolus intravenously injection. Ambulatory Renal Monitor (ARM) is a portable and non invasive device which monitors extracorporeally the clearance of intravenously injected 99mTc-DTPA. We examined correlation between half-time of clearance estimated by ARM and glomerular filtration rare, and clinical usefulness of ARM for a renal function monitoring.

The purposes of this paper are to describe the results obtained through basic analysis experiments and reproducibility in normal control, and its clinical application for 9 renal transplant patients, three drug-induced renal damage, one acute renal failure, one hemolytic uremic syndrome (HUS), two chronic nephritis, one donor of renal transplantation, one ureteral tumor, three renal tumors, two ureteral stones, one bilateral hydronephrosis and two normal controls. The half time of clearance of the tracer measured by an ARM. (ARM-HTC) is compared with the half time of clearance of the tracer measured by repeated blood sampling (Sampling-HTC) as a golden standard, serum creatinine and creatinine clearance.

A significant correlation (linear) was detected when ARM-HTC was compared with Sampling-HTC (r = 0.91), 1/serum creatinine (r = 0.85) or creatinine clearance (r = 0.82), although ARM-HTC showed a delay compared with Sampling-HTC.

The reason of this delay may be due to a difference in half-time when the tracer distributed in the blood and tissue. The results indicate that the estimation of 99mTc-DTPA clearance by ARM is valuable for renal function evaluation in wide ranges of renal function and in different origins of renal dysfunction such as in renal transplantation.