title: Correlations between physiological parameters related with kidney function and minute-by-minute urine output.
abstract: OBJECTIVE
  Recently, devices capable of measuring minute-by-minute urine output (UOm) have become available. It is not known how UOm correlates with physiological parameters in normal conditions and in disease states characterized by vascular dysfunction. This paper analyzes correlations between UOm and physiological parameters related to kidney perfusion to provide some insight about UOm pathophysiological interpretation and its relationship with renal blood flow.
  
  
  METHODS
  We studied 14 male pigs were anesthetized, tracheostomized, and mechanically ventilated. Mean systemic blood pressure (PART), mean pulmonary artery blood pressure (PPA), carotid artery blood flow (QCA), as well as total (QREN), cortical (QCOR) and medullary (QMED) renal blood flows, and the renal resistive index (RRI) were measured or calculated. Animals received an intravenous dose of live E. coli for the induction of sepsis (septic group), or an equivalent amount of normal saline (nonseptic group). Three groups were studied: nonseptic (n = 6) and septic (n = 4), both receiving for resuscitation NaCl 0.9% at 4 mL/kg per h; and septic (n = 4), receiving for resuscitation NaCl 0.9% at 17 mL/kg per h. Animals were monitored for 5 h after the induction of sepsis.
  
  
  RESULTS
  In septic animals, UOm was strongly positively correlated with QREN(Kendall's τ = 0.770, P < 0.05), QCOR(τ = -0.566, P < 0.05) and QMED(τ = 0.632, P < 0.05); and negatively correlated with PPA(τ = -0.524, P < 0.05) and RRI (τ = -0.672, P < 0.05). Control animals exhibited weaker correlations.
  
  
  CONCLUSIONS
  UOm is a good physiological surrogate marker of total and regional renal blood flows and vascular resistance, particularly under septic conditions, probably reflecting glomerulo-tubular dysfunction in sepsis.
authors.affiliation: Department of Information Systems Engineering, University San Pablo CEU, Madrid, Spain.
authors.forename: Abraham
authors.initials: A
authors.lastname: Otero
authors.affiliation: University Hospital of Getafe, Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Cardinal-Fernández
authors.affiliation: University Hospital of Getafe, Madrid, Spain.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Nin
authors.affiliation: University Hospital of Getafe, Madrid, Spain.
authors.forename: Yeny
authors.initials: Y
authors.lastname: Rojas
authors.affiliation: University Hospital of Getafe, Madrid, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Oteiza
authors.affiliation: European University, Madrid, Spain.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Garcia-Carmona
authors.affiliation: Department of Information Systems Engineering, University San Pablo CEU, Madrid, Spain.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Caffarena
authors.affiliation: University Hospital of Getafe, Madrid, Spain.|CIBER of respiratory diseases, Madrid, Spain.|European University, Madrid, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Lorente
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004926:Escherichia coli; D004927:Escherichia coli Infections / Q000175:diagnosis* / Q000382:microbiology / Q000503:physiopathology; D007668:Kidney / Q000098:blood supply / Q000503:physiopathology*; D007677:Kidney Function Tests; D008297:Male; D008954:Models, Biological; D011237:Predictive Value of Tests; D012079:Renal Circulation; D018805:Sepsis / Q000175:diagnosis* / Q000382:microbiology / Q000503:physiopathology; D034421:Sus scrofa; D013997:Time Factors; D014554:Urination; D014655:Vascular Resistance
keywords: acute kidney injury; automatic measurement; minute-by-minute urine output; monitoring; renal blood flow; sepsis