title: A multidisciplinary approach to reducing spurious hyperkalemia in hospital outpatient clinics.
abstract: OBJECTIVE
  To describe a multidisciplinary effort to investigate and reduce the occurence of outpatient spurious hyperkalaemia.
  
  
  BACKGROUND
  Spurious hyperkalemia is a falsely elevated serum potassium result that does not reflect the in vivo condition of a person. A common practice of fist clenching/pumping during phlebotomy to improve vein visualisation is an under-appreciated cause of spurious hyperkalemia.
  
  
  METHODS
  Pre- and postinterventional study.
  
  
  METHODS
  Objective evidence of spurious hyperkalaemia was sought by reviewing archived laboratory results. A literature review was undertaken to summarise known causes of spurious hyperkalaemia and develop a best practice in phlebotomy. Subsequently, nurses from the Urology Clinic were interviewed, observed and surveyed to understand their phlebotomy workflow and identify potential areas of improvement by comparing to the best practice in phlebotomy. Unexplained (potentially spurious) hyperkalaemia was defined as a serum potassium of >5·0 mmol/l in a patient without stage 5 chronic kidney disease or haemolysed blood sample.
  
  
  CONCLUSIONS
  Nurses from the Urology Clinic showed significant knowledge gap regarding causes of spurious hyperkalaemia when compared to the literature review. Direct observation revealed patients were routinely asked to clench their fists, which may cause spurious hyperkalaemia. Following these observations, several educational initiatives were administered to address the knowledge gap and stop fist clenching. The rate of unexplained hyperkalaemia at the Urology clinic reduced from a baseline of 16·0-3·8%, 58 weeks after intervention. Similar education intervention was propagated to all 18 other specialist outpatient clinic locations, which saw their rate of unexplained hyperkalaemia decrease from 5·4 to 3·7%. To ensure sustainability of the improvements, the existing phlebotomy standard operating protocol, educational and competency testing materials at variance with the best practice were revised.
  
  
  CONCLUSIONS
  A simple intervention of avoiding fist clenching/pumping during phlebotomy produced significant reduction in the rate of spurious hyperkalemia.
authors.affiliation: Department of Laboratory Medicine, National University Hospital, Singapore City, Singapore.
authors.forename: Tze Ping
authors.initials: TP
authors.lastname: Loh
authors.affiliation: Department of Laboratory Medicine, National University Hospital, Singapore City, Singapore.
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Sethi
mesh_terms: D005260:Female; D006801:Humans; D006947:Hyperkalemia / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010044:Outpatient Clinics, Hospital; D018962:Phlebotomy / Q000009:adverse effects* / Q000379:methods / Q000592:standards
keywords: fist clenching; laboratory error; phlebotomy; preanalytical; pseudohyperkalemia; spurious hyperkalemia