Augmented renal clearance in east coast Malaysia intensive care setting : assessment of prevalence, risk factors and outcomes

Abstract

Introduction: Augmented renal clearance (ARC) is a phenomenon where there is elevated renal clearance and defined by creatinine clearance > 130ml/min/1.73m2. ARC results in changes of the pharmacokinetic and pharmacodynamic of antimicrobial therapy being administered, which may result in its subtherapeutic dose. We evaluated the prevalence, risk factors and outcome of ARC in critically ill patients in two Intensive Care Unit in Kuantan. Methods: This is a multicentre, prospective observational study of critically ill patients. Inclusion criteria were ICU patients older than 15 years old with plasma creatinine <130 µmol/l and arterial and urinary catheter inserted. 4 hours serum and urinary creatinine and flow rate were measured for a day and creatinine clearance (CrCl) calculated. ARC is defined as CrCl of more 130 ml/min/1.73. Patient were follow up until hospital discharge. Results: Among 102 patients recruited, of which 57 (55.9%) had ARC. Those with younger age (39.9±19 years old, p=0.013) and lower SOFA score (2.8±2.6, p=0.012) is at more risk to develop ARC. No significant difference in other risk factors such as male and trauma. There was no difference in the ICU and hospital mortality (p=0.652 and p=0.128). Surprisingly, duration of ICU admission amongst survivors was shorter in patients with ARC but statistically not significant (4 ± 6 vs 6 ± 7 days, p=0.271). Measured creatinine clearance moderately correlated with the estimated glomerular filtration rate using 4 different formulas (r=0.436-0.552, p<0.0001). Conclusions: ARC occurs in almost half of critically ill patients and more common in younger age and lower SOFA score. However, there was no difference in the outcome in this study. Estimated Glomerular Filtration Rate may be used as surrogate for measure creatinine clearance in detecting ARC.