title: Renal perfusion assessment by renal Doppler during fluid challenge in sepsis.
abstract: OBJECTIVE
  To assess renal resistive index variations in response to fluid challenge.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Three ICUs in French teaching hospitals.
  
  
  METHODS
  Consecutive patients receiving mechanical ventilation and requiring a fluid challenge.
  
  
  METHODS
  Resistive index measurement before and after fluid challenge.
  
  
  RESULTS
  Renal Doppler was used to measure resistive index and esophageal Doppler to monitor aortic blood flow. Of the 35 included patients, 17 (49%) met our definition for fluid challenge responsiveness, that is, had at least a 10% increase in aortic blood flow. After fluid challenge, mean arterial pressure increased from 73 mm Hg (interquartile range 68-79) to 80 mm Hg (75-86; p < 0.0001) and stroke volume from 50 mL (30-77) to 55 mL (39-84; p < 0.0001). Stroke volume changes after fluid challenge were +28.6% (+18.8% to +38.8%) in fluid challenge responders and +3.1% (-1.6% to 7.4%) in fluid challenge nonresponders. Renal resistive index was unchanged after fluid challenge in both nonresponders (0.72 [0.67-0.75] before and 0.71 [0.67-0.75] after fluid challenge; p = 0.62) and responders (0.70 [0.65-0.75] before and 0.72 [0.68-0.74] after fluid challenge; p = 0.11). Stroke volume showed no correlations with resistive index changes after fluid challenge in the overall population (r² = 0.04, p = 0.25), in fluid challenge responders (r² = -0.02, p = 0.61), or in fluid challenge nonresponders (r² = 0.08, p = 0.27). Stroke volume did not correlate with resistive index changes after fluid challenge in the subgroups without acute kidney injury (AKIN definition), with transient acute kidney injury, or with persistent acute kidney injury.
  
  
  CONCLUSIONS
  Systemic hemodynamic changes induced by fluid challenge do not translate into resistive index variations in patients without acute kidney injury, with transient acute kidney injury, or with persistent acute kidney injury.
authors.affiliation: Réanimation médicale, Hôpital Saint Louis, Assistance Publique Hôpitaux de Paris, Paris, France.
authors.forename: David
authors.initials: D
authors.lastname: Schnell
authors.forename: Laurent
authors.initials: L
authors.lastname: Camous
authors.forename: Stéphane
authors.initials: S
authors.lastname: Guyomarc'h
authors.forename: Jacques
authors.initials: J
authors.lastname: Duranteau
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Canet
authors.forename: Pierre
authors.initials: P
authors.lastname: Gery
authors.forename: Anne-Sylvie
authors.initials: AS
authors.lastname: Dumenil
authors.forename: Fabrice
authors.initials: F
authors.lastname: Zeni
authors.forename: Elie
authors.initials: E
authors.lastname: Azoulay
authors.forename: Michael
authors.initials: M
authors.lastname: Darmon
mesh_terms: D058186:Acute Kidney Injury / Q000000981:diagnostic imaging* / Q000209:etiology; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D016638:Critical Illness / Q000628:therapy; D005260:Female; D005440:Fluid Therapy / Q000379:methods; D005602:France; D006439:Hemodynamics / Q000502:physiology*; D006784:Hospitals, Teaching; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D011379:Prognosis; D011446:Prospective Studies; D012079:Renal Circulation / Q000502:physiology; D012121:Respiration, Artificial; D018805:Sepsis / Q000150:complications* / Q000175:diagnosis / Q000628:therapy*; D012772:Shock, Septic / Q000150:complications / Q000175:diagnosis / Q000628:therapy; D013318:Stroke Volume / Q000502:physiology; D018608:Ultrasonography, Doppler / Q000379:methods; D014655:Vascular Resistance / Q000502:physiology*