Measuring total body water in peritoneal dialysis patients using an ethanol dilution technique

Kidney Int. 1999 Dec;56(6):2297-303. doi: 10.1038/sj.ki.4491173.

Abstract

Measuring total body water in peritoneal dialysis patients using an ethanol dilution technique.

Background: The accuracy with which total body water (TBW) is estimated is a direct determinant of the reliability of Kt/V urea measurements in peritoneal dialysis (PD) patients. Ethanol dilution has been previously shown to be a reliable measure of TBW. Advances in breath alcohol technology make this a feasible clinical tool.

Methods: We gave 19 fasting chronic PD patients 0.3 g/kg of ethanol (EtOH) orally on two separate occasions. Breath alcohol concentrations (BrACs), determined by dual-beam infrared analysis, were recorded at baseline and periodically thereafter until BrACs were less than 0.01%. The TBW was then determined by standard pharmacokinetic techniques.

Results: TBW measurements were reproducible, with a mean between-run difference of -0.004 liter/kg (95% limits of agreement -0.040 to 0. 032 by Bland-Altman). The Watson equations tended to underestimate TBW, with a mean difference (EtOH - Watson) of +3.0 liters (SD 4.0 liters, P = 0.004) and a mean absolute difference of 4.1 liters (SD 2.7 liters, range -4.4 to 9.5 liters). Kt/V was calculated from dialysate and urine collection, using V as determined from TBW estimates from EtOH and Watson. The mean Kt/V(EtOH) was 2.31 (SD 0. 50) compared with 2.46 (SD 0.52) using Watson. The mean absolute difference between the two Kt/V estimates was 0.26 (SD 0.20, range -0.87 to 0.57), with Kt/V overestimated by Watson in 14 patients. EtOH was well tolerated, and the procedure was completed in about four hours.

Conclusions: Measuring V by the BrAC technique does not require blood sampling, is reliable, and is reproducible. It is a potentially useful method for a periodic determination of volume that may allow for more accurate Kt/V measurement in PD patients.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't
  • Technical Report

MeSH terms

  • Administration, Oral
  • Adult
  • Aged
  • Body Water*
  • Breath Tests / methods
  • Ethanol*
  • Female
  • Humans
  • Indicator Dilution Techniques / standards
  • Kidney Failure, Chronic / diagnosis
  • Kidney Failure, Chronic / metabolism
  • Kidney Failure, Chronic / therapy*
  • Kinetics
  • Male
  • Middle Aged
  • Peritoneal Dialysis / standards*
  • Predictive Value of Tests
  • Prospective Studies
  • Reproducibility of Results
  • Solvents*
  • Urea / analysis
  • Water-Electrolyte Balance

Substances

  • Solvents
  • Ethanol
  • Urea