title: Select critically ill patients at risk of augmented renal clearance: experience in a Malaysian intensive care unit.
abstract: Augmented renal clearance (ARC) refers to increased solute elimination by the kidneys. ARC has considerable implications for altered drug concentrations. The aims of this study were to describe the prevalence of ARC in a select cohort of patients admitted to a Malaysian intensive care unit (ICU) and to compare measured and calculated creatinine clearances in this group. Patients with an expected ICU stay of <24 hours plus an admission serum creatinine concentration <120 µmol/l, were enrolled from May to July 2013. Twenty-four hour urinary collections and serum creatinine concentrations were used to measure creatinine clearance. A total of 49 patients were included, with a median age of 34 years. Most study participants were male and admitted after trauma. Thirty-nine percent were found to have ARC. These patients were more commonly admitted in emergency (P=0.03), although no other covariants were identified as predicting ARC, likely due to the inclusion criteria and the study being under-powered. Significant imprecision was demonstrated when comparing calculated Cockcroft-Gault creatinine clearance (Crcl) and measured Crcl. Bias was larger in ARC patients, with Cockcroft-Gault Crcl being significantly lower than measured Crcl (P <0.01) and demonstrating poor correlation (rs=-0.04). In conclusion, critically ill patients with 'normal' serum creatinine concentrations have varied Crcl. Many are at risk of ARC, which may necessitate individualised drug dosing. Furthermore, significant bias and imprecision between calculated and measured Crcl exists, suggesting clinicians should carefully consider which method they employ in assessing renal function.
authors.affiliation: Burns, Trauma and Critical Care Research Centre, Royal Brisbane and Women's Hospital, Herston, Queensland.
authors.forename: S
authors.initials: S
authors.lastname: Adnan
authors.affiliation: Hospital Sungai Buloh, Sungai Buloh, Malaysia.
authors.forename: S
authors.initials: S
authors.lastname: Ratnam
authors.affiliation: Hospital Sungai Buloh, Sungai Buloh, Malaysia.
authors.forename: S
authors.initials: S
authors.lastname: Kumar
authors.affiliation: University of Queensland Centre for Clinical Research (UQCCR), Brisbane, Queensland.
authors.forename: D
authors.initials: D
authors.lastname: Paterson
authors.affiliation: Burns, Trauma and Critical Care Research Centre, Royal Brisbane and Women's Hospital, Herston, Queensland.
authors.forename: J
authors.initials: J
authors.lastname: Lipman
authors.affiliation: Burns, Trauma and Critical Care Research Centre, Royal Brisbane and Women's Hospital, Herston, Queensland.
authors.forename: J
authors.initials: J
authors.lastname: Roberts
authors.affiliation: Intensive Care Unit, Alfred Hospital, Melbourne, Victoria.
authors.forename: A A
authors.initials: AA
authors.lastname: Udy
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood* / Q000652:urine*; D016638:Critical Illness; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007297:Inpatients / Q000706:statistics & numerical data; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D007668:Kidney / Q000503:physiopathology*; D007677:Kidney Function Tests / Q000379:methods* / Q000706:statistics & numerical data*; D008296:Malaysia; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D055815:Young Adult
chemical_list: D003404:Creatinine
keywords: antibiotic dosing; augmented renal clearance; creatinine clearance; critical illness; glomerular filtration rate