SERIOUS RENAL IMPAIRMENT IS ASSOCIATED WITH LONG-TERM PARENTERAL-NUTRITION

Thirty-three current long-term total parenteral nutrition (TPN) patien ts (13 men, 20 women) aged 21 to 79 years were prospectively studied t o evaluate their change in glomerular filtration rate since beginning TPN. Creatinine clearance (CrCl) from the subject's initial home TPN c linic visit and at present were estimated from standard formulas and c ompared. The CrCl in 12 patients who had received home TPN for > 10 ye ars was estimated retrospectively on a yearly basis. The estimated CrC l as an accurate measure of glomerular filtration rate was confirmed b y measuring plasma indium-111 diethylenetriamine pentaacetic acid clea rance. The mean daily intravenous protein intake and days during which nephrotoxic medications were used and number of bacteremic/fungemic e pisodes were determined for each subject. CrCl declined by 3.5 +/- 6.3 % per year (p = .004). Twenty-nine of 33 patients had decreases of 0.6 % to 15.4% per year. Tubular function, as determined by the tubular re absorption of phosphate, was impaired in 52% of the subjects. The intr avenous protein load averaged 1.28 +/- 0.32 g/kg per day, nephrotoxic drug use averaged 3.4 +/- 4.0% of all days on home TPN, and each patie nt averaged 2.3 episodes of bacteremia or fungemia since home TPN was started (0.5 +/- 0.5 episodes per year). When all factors were assesse d simultaneously, nephrotoxic drug use, episodes of bacteremia/fungemi a, and age accounted for approximately 46% of the variability in CrCl. When bacteremia/fungemia was expressed as a yearly rate, nephrotoxic drug use assumed no role in the glomerular filtration rate determinati on; infection rate and age alone accounted for 53% of the CrCl variabi lity. We describe a profound decrease in renal function associated wit h long-term TPN, most of which is largely unexplained.