title: Circulating blood volume measured by pulse dye-densitometry: comparison with (131)I-HSA analysis.
abstract: BACKGROUND
  Pulse dye-densitometry (PDD) is a newly developed technique for monitoring the arterial concentration of indocyanine green. Using this method, circulating blood volume (CBV) can be calculated without using radioisotopes. In this study, the CBV value obtained by PDD was validated by comparison using the human serum albumin ((131)I-HSA) dilution method.
  
  
  METHODS
  Eleven healthy volunteers underwent placement of cannulae into the radial artery and antecubital vein for withdrawal of blood samples and injection of indicator. Probes for PDD were attached to the right nostril and the right index finger. Indocyanine green (20 mg), dissolved in 4 ml water, and 25 microCi (131)I-HSA in 1 ml distilled water were injected simultaneously into the left antecubital vein. Blood samples were withdrawn 3, 6, 10, 20, 30, and 45 min after injection, then processed for spectrophotometric measurement of indocyanine green and scintillation counting.
  
  
  RESULTS
  The blood dye concentration correlated well with the values obtained by PDD (r=0.986, imprecision 0.04+/-0.11 mg/l, 10.0+/-31%. The imprecision of the CBV value obtained by PDD (nose probe) and by the (131)I-HSA dilution method was 3.99+/-10.54%, 0.259+/-0.593 l. The imprecision of the CBV obtained by in vitro spectrophotometry compared with PDD was 2.47+/-9.00%, 0.100+/-0.446 l.
  
  
  CONCLUSIONS
  This newly developed, less invasive method can measure CBV with an imprecision of 3.99+/-10.54%, 0.259+/-0.593 l (nose probe), and thus is also as accurate as the conventional radioisotope method.
authors.affiliation: Department of Anesthesiology, Kyorin University School of Medicine, Mitaka-City, Tokyo, Japan. dy8t-iijm@asahi-net.or.jp
authors.forename: T
authors.initials: T
authors.lastname: Iijima
authors.forename: Y
authors.initials: Y
authors.lastname: Iwao
authors.forename: H
authors.initials: H
authors.lastname: Sankawa
mesh_terms: D000328:Adult; D001811:Blood Volume Determination / Q000379:methods*; D004396:Coloring Agents; D003720:Densitometry; D005260:Female; D006801:Humans; D007208:Indocyanine Green; D008297:Male; D011865:Radioisotope Dilution Technique; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012711:Serum Albumin, Radio-Iodinated
chemical_list: D004396:Coloring Agents; D019275:Radiopharmaceuticals; D012711:Serum Albumin, Radio-Iodinated; D007208:Indocyanine Green