TRANSCUTANEOUS RENAL-FUNCTION MONITOR - PRECISION DURING UNSTEADY HEMODYNAMICS

Objective. Hospital acquired renal dysfunction, most commonly caused b y renal hypoperfusion, dramatically increases mortality in intensive c are patients. Glomerular filtration rate (GFR) is rapidly altered duri ng renal hypoperfusion, and a more rapid means of GFR measurement map prompt institution of renal-specific therapy. We hypothesized that a t ranscutaneous renal function monitor can rapidly and accurately assess acute changes in GFR within a time frame much shorter than the 2-4 ho urs currently available. Methods. The study design was a prospective d etermination of the capability to measure GFR transcutaneously. In thr ee different studies, concurrent transcutaneous measurement of GFR, us ing the rate of disappearance of Tc-99m-diethylenetriaminepentaacetic acid (DTPA), was compared by correlation and standard deviation (SD) t o reference standards of DTPA plasma clearance, serum inulin clearance , or serum creatinine. Results. Continuous transcutaneous clearance (T C) measurement correlated with standard DTPA plasma clearance techniqu es (r = 0.93). Acute pharmacologically induced changes in GFR are dete ctable by TC measurement within 12-20 min, a time interval significant ly affected by the data acquisition interval. Excess patient movement in the ICU patients created clearance artifacts in 50% of clearance tr aces. Retrospective analysis of ICU patient data reveal TC measurement s are 93% specific and 92% sensitive for serum creatinine levels in cr itically ill patients. Conclusions. TC monitoring provides prompt indi cation of directional changes in GFR and may provide the clinician war ning of inadequate resuscitation. Prospective analysis of the specific ity, sensitivity, and TC guided renal-specific resuscitation is needed .