[Analysis of indocyanine green plasma disappearance rate in clinical practice].

Objective: To justify the optimal method for determining indocyanine green plasma disappearance rate (PDR_ICG).

Material and methods: We analyzed PDR_ICG in intensive care units. Indocyanine green was administered intravenously at a dose of 0.25 mg/kg. PDR_ICG was analyzed simultaneously by using of three methods: 1) PDD (PiCCO2 LiMON device), 2) SBS with analysis of plasma samples on precise spectrophotometer, 3) SBS with analysis of plasma samples on simple experimental photometer.

Results: PDD method was used for 346 PDR_ICG tests in 256 patients. Of these, 14.3% of measurements were erroneous. Paired tests using PDD and SBS methods were performed in 299 cases. SBS method resulted erroneous data in 0.6% of cases. Certain correlation (r=0.79, p<0.001) was found between the reference method (SBS with spectrophotometry) and the PDD method. Bland-Altman plot for these two methods showed that proportional bias of mean difference was caused by extremely high PDR_ICG of the PDD method (for example, more than 30%/min). Comparison of two SBS variants (spectrophotometer and experimental photometer) revealed good correlation (r=0.91, p<0.001).

Conclusion: SBS method for measuring PDR_ICG ensures accurate results under mechanical interferences in patients with impaired capillary blood flow. This eliminates the need for redo measurement. Duplication of the PDD and SBS methods is recommended when repeating the test is not possible (organ donors).