title: Replacement of 24-h creatinine clearance by 2-h creatinine clearance in intensive care unit patients: a single-center study.
abstract: OBJECTIVE
  To estimate the usefulness of 2-h creatinine clearance (CrCl) in the ICU and define variables that may reduce agreement.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Polyvalent ICU of a university hospital.
  
  
  METHODS
  359 patients.
  
  
  METHODS
  We compared 24-h CrCl (CrCl-24h), as the standard measure, with 2-h CrCl (CrCl-2h) (at the start of the period) and the Cockroft-Gault equation (Ck-G).
  
  
  RESULTS
  The 2-h sample was lost in two patients (0.6%) and the 24-h sample was lost in 50 patients (13.9%). The mean Ck-G was 87.4+/-3.05, with CrCl-2h 109.2+/-4.46 and CrCl-24h 100.9+/-4.21 ml/min/1.73 m2 (r2 of 0.88 for CrCl-2h and 0.84 for Ck-G). The differences from ClCr-24h were 21.8+/-3.3 (p<0.001) for the Ck-G and 8.3+/-2.6 (p<0.05) for CrCl-2h (p<0.05). In the subgroup of patients with CrCl-24h<100 ml/min/1.73 m2, the CrCl-24h value was 52.9+/-2.71 vs. 51.6+/-2.14 for CrCl-2h (p=ns) and 57.6+/-2.56 (p<0.001) for the Ck-G. Patients with CrCl<100 ml/min only showed variability in hyperglycemia during the 24-h period.
  
  
  CONCLUSIONS
  In intensive care patients, 24-h CrCl results in a large proportion of non-valid determinations, even under conditions of close monitoring. Two-hour CrCl is an adequate substitute, even in patients who are unstable or who have irregular diuresis where a 24-h collection is impossible. The Cockroft-Gault equation seems less useful in this setting.
authors.affiliation: Intensive Care Medicine, Carlos Haya University Hospital, 29018 Malaga, Spain. mehguci@wanadoo.es
authors.forename: Manuel E
authors.initials: ME
authors.lastname: Herrera-Gutiérrez
authors.forename: Gemma
authors.initials: G
authors.lastname: Seller-Pérez
authors.forename: Esther
authors.initials: E
authors.lastname: Banderas-Bravo
authors.forename: Javier
authors.initials: J
authors.lastname: Muñoz-Bono
authors.forename: Miguel
authors.initials: M
authors.lastname: Lebrón-Gallardo
authors.forename: Juan F
authors.initials: JF
authors.lastname: Fernandez-Ortega
mesh_terms: D000465:Algorithms; D003401:Creatine / Q000097:blood / Q000378:metabolism*; D003422:Critical Care; D016638:Critical Illness; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D007668:Kidney / Q000293:injuries; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians'; D011446:Prospective Studies; D013030:Spain
chemical_list: D003401:Creatine