title: Stability of plasma creatinine concentrations in acute complex long-stay admissions to a general medical service.
abstract: Assessment of glomerular filtration rate (GFR) is essential for calculating safe dosages of renally cleared drugs. Formulae for estimating reliable GFRs assume that plasma creatinine concentrations are stable. This study evaluates the variability of plasma creatinine (PCr) concentrations in patients admitted acutely to hospital. From 2,293 newly admitted patients, those in whom a subsequent clinically significant change (> 20%) in PCr had occurred were identified. Median age was 81.1 years. Median baseline PCr was 90 umol/l (eGFR 60 ml/min). In total, 46.3% of the patients had a PCr that varied > 20% from baseline three to seven days following admission. A 10-year increase in age increased the odds of a rise in PCr over the next week by 11.1% (odds ratio = 1.11, 95% confidence interval = 1.03, 1.20; p = 0.007). Overall, baseline creatinine was a poor predictor of subsequent variation in PCr. GFR formulae for calculating renally-cleared drug dosages should be used with caution in elderly patients admitted acutely to hospital.
authors.affiliation: University of Adelaide, Australia.
authors.forename: Donna
authors.initials: D
authors.lastname: Siriwardane
authors.forename: Richard
authors.initials: R
authors.lastname: Woodman
authors.forename: Paul
authors.initials: P
authors.lastname: Hakendorf
authors.forename: Jennifer H
authors.initials: JH
authors.lastname: Martin
authors.forename: Graham H
authors.initials: GH
authors.lastname: White
authors.forename: David I
authors.initials: DI
authors.lastname: Ben-Tovim
authors.forename: Campbell H
authors.initials: CH
authors.lastname: Thompson
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D003404:Creatinine / Q000097:blood*; D016638:Critical Illness / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006769:Hospitals, General; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D010343:Patient Admission; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D013021:South Australia; D013997:Time Factors
chemical_list: D003404:Creatinine