title: Microcirculatory alterations during continuous renal replacement therapy in ICU: A novel view on the 'dialysis trauma' concept.
abstract: OBJECTIVE
  The purpose of this study was to evaluate microcirculation over 24 h renal replacement therapy (CRRT) in critically ill patients.
  
  
  METHODS
  We conducted a single-center, prospective, observational study, measuring microcirculation parameters, monitored by near infrared spectroscopy (NIRS) before hemodiafiltration onset (H0), and at six (H6) and 24 h (H24) during CRRT in critically ill patients. Serum Cystatin C (sCysC) and soluble (s)E-selectin levels were measured at the same time points. Twenty-eight patients [19 men (68%)] were included in the study.
  
  
  RESULTS
  Tissue oxygen saturation (StO2, %) [76.5 ± 12.5 (H0) vs 75 ± 11 (H6) vs 70 ± 16 (H24), p = 0.04], reperfusion rate, indicating endothelial function (EF, %/sec) [2.25 ± 1.44 (H0) vs 2.1 ± 1.8 (H6) vs 1.6 ± 1.4 (H24), p = 0.02] and sCysC (mg/L) [2.7 ± 0.8 (H0) vs 2.2 ± 0.6 (H6) vs 1.8 ± 0.8 (H24), p < 0.0001] significantly decreased within the 24 h CRRT. Change of EF positively correlated with changes of sCysC within 24 h CRRT (r = 0.464, p = 0.013) while in patients with diabetes the change of StO2 correlated with dose (r = − 0.8, p = 0.01). No correlation existed between hemoglobin and temperature changes with the deteriorated microcirculation indices. sE-Selectin levels in serum were elevated; no difference was established over the 24 h CRRT period. A strong correlation existed between the sE-Selectin concentration change at H6 and H24 and the mean arterial pressure change in the same period (r = 0.77, p < 0.001).
  
  
  CONCLUSIONS
  During the first 24 h of CRRT implementation in critically ill patients, deterioration of microcirculation parameters was noted. Microcirculatory alterations correlated with sCysC changes and with dose in patients with diabetes.
authors.affiliation: First Critical Care Department, 'Evangelismos' General Hospital, National and Kapodistrian University of Athens, Greece.
authors.forename: Chrysoula
authors.initials: C
authors.lastname: Pipili
authors.affiliation: First Critical Care Department, 'Evangelismos' General Hospital, National and Kapodistrian University of Athens, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Vasileiadis
authors.affiliation: First Critical Care Department, 'Evangelismos' General Hospital, National and Kapodistrian University of Athens, Greece.
authors.forename: Eirini
authors.initials: E
authors.lastname: Grapsa
authors.affiliation: First Critical Care Department, 'Evangelismos' General Hospital, National and Kapodistrian University of Athens, Greece.
authors.forename: Elli-Sophia
authors.initials: ES
authors.lastname: Tripodaki
authors.affiliation: Laboratory of Biochemistry, 'Evangelismos' Hospital, Athens, Greece.
authors.forename: Sophia
authors.initials: S
authors.lastname: Ioannidou
authors.affiliation: First Critical Care Department, 'Evangelismos' General Hospital, National and Kapodistrian University of Athens, Greece.
authors.forename: Adroula
authors.initials: A
authors.lastname: Papastylianou
authors.affiliation: First Critical Care Department, 'Evangelismos' General Hospital, National and Kapodistrian University of Athens, Greece.
authors.forename: Stelios
authors.initials: S
authors.lastname: Kokkoris
authors.affiliation: First Critical Care Department, 'Evangelismos' General Hospital, National and Kapodistrian University of Athens, Greece.
authors.forename: Christina
authors.initials: C
authors.lastname: Routsi
authors.affiliation: Blood Transfusion Department, Aretaieion Hospital, Athens University Medical School, Athens, Greece.
authors.forename: Marianna
authors.initials: M
authors.lastname: Politou
authors.affiliation: First Critical Care Department, 'Evangelismos' General Hospital, National and Kapodistrian University of Athens, Greece. Electronic address: a.icusn@gmail.com.
authors.forename: Serafeim
authors.initials: S
authors.lastname: Nanas
mesh_terms: D000368:Aged; D062186:Arterial Pressure; D015415:Biomarkers / Q000097:blood; D001783:Blood Flow Velocity; D016638:Critical Illness; D055316:Cystatin C / Q000097:blood; D019040:E-Selectin / Q000097:blood; D005260:Female; D006115:Greece; D006225:Hand; D017583:Hemodiafiltration / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007362:Intensive Care Units; D007674:Kidney Diseases / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply*; D010100:Oxygen / Q000097:blood; D010865:Pilot Projects; D011446:Prospective Studies; D012039:Regional Blood Flow; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D019040:E-Selectin; C546936:SELE protein, human; D010100:Oxygen
keywords: Continuous renal replacement therapy; Cystatin C; Dialytrauma; Near infrared spectroscopy; Tissue oxygenation