title: Resistive Index or color-Doppler semi-quantitative evaluation of renal perfusion by inexperienced physicians: results of a pilot study.
abstract: BACKGROUND
  Doppler-based renal resistive index (RI) calculation may help in the early detection of acute kidney injury (AKI). Its feasibility and reproducibility by inexperienced operators remain unknown. The main objective of this study was to compare performances of junior and senior operators in assessing renal perfusion using both the semiquantitative color-Doppler scale and RI calculation.
  
  
  METHODS
  Prospective cohort study performed in 3 ICUs. Inexperienced juniors physicians attended a half-day course on renal perfusion assessment using RI calculation and color-Doppler (from 0, absence of renal perfusion; to 3, renal vessels identifiable in the entire field of view). Junior and senior operators used both methods in 69 mechanically ventilated patients, in blind fashion.
  
  
  RESULTS
  Failure to obtain RI occurred for a junior operator in a single patient. RI and color-Doppler semi-quantitative values obtained by operators were correlated (r²=0.64 and r²=0.61, respectively). Systematic bias across operators as assessed using Bland-Altman plots was negligible (-0.001 and -0.29, respectively), although precision was limited (95% confidence intervals, +0.105 to -0.107 and +0.98 to -1.04, respectively). RI calculation and semi-quantitative assessment performed well for diagnosing persistent AKI (area under the receiver-operating characteristic curve, 0.84 [95% confidence interval, 0.73-0.97] and 0.87 [0.77-0.97], respectively).
  
  
  CONCLUSIONS
  A brief course on renal Doppler allowed inexperienced operators to assess effectively renal perfusion with a good reliability when compared to senior operators. In addition, our results suggest the good diagnostic performance of both Doppler-based RI and semi-quantitative renal perfusion assessment in predicting short-term renal dysfunction reversibility.
authors.affiliation: Réanimation médicale, Hôpital Saint Louis, Assistance Publique Hôpitaux de Paris, Paris, France, Paris-7 University, Paris, France - michael.darmon@chu-st-etienne.fr.
authors.forename: D
authors.initials: D
authors.lastname: Schnell
authors.forename: M
authors.initials: M
authors.lastname: Reynaud
authors.forename: M
authors.initials: M
authors.lastname: Venot
authors.forename: A L
authors.initials: AL
authors.lastname: Le Maho
authors.forename: M
authors.initials: M
authors.lastname: Dinic
authors.forename: M
authors.initials: M
authors.lastname: Baulieu
authors.forename: G
authors.initials: G
authors.lastname: Ducos
authors.forename: J
authors.initials: J
authors.lastname: Terreaux
authors.forename: F
authors.initials: F
authors.lastname: Zeni
authors.forename: E
authors.initials: E
authors.lastname: Azoulay
authors.forename: F
authors.initials: F
authors.lastname: Meziani
authors.forename: J
authors.initials: J
authors.lastname: Duranteau
authors.forename: M
authors.initials: M
authors.lastname: Darmon
mesh_terms: D058186:Acute Kidney Injury / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D000328:Adult; D000368:Aged; D002983:Clinical Competence; D003422:Critical Care; D006801:Humans; D008875:Middle Aged; D010865:Pilot Projects; D012079:Renal Circulation; D015203:Reproducibility of Results; D012121:Respiration, Artificial; D018615:Ultrasonography, Doppler, Color; D014655:Vascular Resistance