Augmented renal clearance in the ICU: estimation, incidence, risk factors and consequences-a retrospective observational study

Abstract

Background: Augmented renal clearance (ARC) remains poorly evaluated in ICU. The objective of this study is to provide a full description of ARC in ICU including prevalence, evolution profile, risk factors and outcomes.

Methods: This was a retrospective, single-center, observational study. All the patients older than 18 years admitted for the first time in Medical ICU, Bichat, University Hospital, APHP, France, between January 1, 2017, and November 31, 2020 and included into the Outcomerea database with an ICU length of stay longer than 72 h were included. Patients with chronic kidney disease were excluded. Glomerular filtration rate was estimated each day during ICU stay using the measured creatinine renal clearance (CrCl). Augmented renal clearance (ARC) was defined as a 24 h CrCl greater than 130 ml/min/m².

Results: 312 patients were included, with a median age of 62.7 years [51.4; 71.8], 106(31.9%) had chronic cardiovascular disease. The main reason for admission was acute respiratory failure (184(59%)) and 196(62.8%) patients had SARS-COV2. The median value for SAPS II score was 32[24; 42.5]; 146(44%) and 154(46.4%) patients were under vasopressors and invasive mechanical ventilation, respectively. The overall prevalence of ARC was 24.6% with a peak prevalence on Day 5 of ICU stay. The risk factors for the occurrence of ARC were young age and absence of cardiovascular comorbidities. The persistence of ARC during more than 10% of the time spent in ICU was significantly associated with a lower risk of death at Day 30.

Conclusion: ARC is a frequent phenomenon in the ICU with an increased incidence during the first week of ICU stay. Further studies are needed to assess its impact on patient prognosis.

Keywords: Augmented renal clearance; Epidemiology; Intensive care unit.

Fig. 1

Daily prevalence (A) and cumulative incidence (B) of augmented renal clearance in ICU from day 1 to day 30

Fig. 2

Factors associated with ARC at admission. OR odds ratio, CI 95% confidence interval, HR hazard ratio. Factors tested in multivariate analysis for the of ARC at admission were age, sex (male), cardiovascular comorbidities, immunosuppression, diabetes, SARS-COV2, catecholamines, invasive mechanical ventilation, proton-pump inhibitors, enteral nutrition, aminoglycosides

Fig. 3

Factors associated with late ARC—multivariate analyses. OR odds ratio, CI 95% confidence interval, HR hazard ratio. Factors tested in multivariate analysis for the risk of late ARC were age, sex (male), BMI > 30 kg/m², SARS COV 2 pneumoniae, immunosuppression, catecholamines, KDIGO (Kidney Disease: Improving Global Outcome score), parenteral nutrition, aminoglycosides, vancomycins, proton-pump inhibitors

Fig. 4

Cumulative probability of being at a state at a given time after the ICU stay for patients with (from left to right) ARC at admission, without renal failure or ARC, with KDIGO (KDIGO (Kidney Disease: Improving Global Outcome score) 1 or 2 renal failure, and with KDIGO 3 renal failure at admission

Fig. 5

Association between the percentage of time with ARC (augmented renal clearance) during ICU (intensive care unit) stay and ICU mortality (multivariate logistic regression model), LOS (length of stay)