Published in:
01-11-2007 | Original
Replacement of 24-h creatinine clearance by 2-h creatinine clearance in intensive care unit patients: a single-center study
Published in: Intensive Care Medicine | Issue 11/2007
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Objective
To estimate the usefulness of 2-h creatinine clearance (CrCl) in the ICU and define variables that may reduce agreement.
Design
Prospective study.
Setting
Polyvalent ICU of a university hospital.
Patients
359 patients.
Interventions
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).
Measurements and 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 (r
2 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.