title: Zinc supplementation in intensive care: results of a UK survey.
abstract: OBJECTIVE
  Our laboratory receives many routine requests for plasma zinc analysis from intensive care units (ICUs) throughout Scotland. However, such requests are inappropriate because plasma zinc concentrations fall independently of nutritional deficiency during the systemic inflammatory response and, therefore, in critically ill patients. This survey was performed to investigate how widespread this practice was and if low plasma zinc concentrations were interpreted as zinc deficiency so triggering inappropriate initiation of zinc supplementation.
  
  
  METHODS
  A questionnaire was sent to ICUs throughout the UK; nonresponders were contacted by telephone, and the questionnaire details were recorded. The questionnaire asked if plasma zinc was routinely requested, the frequency of requests, whether patients were supplemented with zinc, and if so, the grounds for supplementation and the dose given.
  
  
  RESULTS
  Plasma measurement of zinc was routinely performed in 18% of UK ICUs. Zinc supplementation was given in 10%, usually as a result of finding low plasma zinc concentrations. Dosages of supplementation varied widely between ICUs: from 0.4 to 135 mg zinc per day. Approximately 6% of ICUs gave very high supplements of zinc of 90 and 135 mg/d.
  
  
  CONCLUSIONS
  The finding of a low plasma zinc concentration in Intensive Therapy Unit patients is often misinterpreted as indicating zinc deficiency and inappropriately prompts zinc supplementation. There is no evidence base to support high-dose zinc supplementation in ICU patients. This practice is justifiable only if future randomized trials demonstrate a benefit.
authors.affiliation: Scottish Trace Element and Micronutrient Reference Laboratory, G4 0SF Glasgow, United Kingdom. Andrew.duncan@ggc.scot.nhs.uk
authors.forename: Andrew
authors.initials: A
authors.lastname: Duncan
authors.forename: Pamela
authors.initials: P
authors.lastname: Dean
authors.forename: Malcolm
authors.initials: M
authors.lastname: Simm
authors.forename: Denis StJ
authors.initials: DS
authors.lastname: O'Reilly
authors.forename: John
authors.initials: J
authors.lastname: Kinsella
mesh_terms: D003422:Critical Care / Q000706:statistics & numerical data*; D019587:Dietary Supplements; D019538:Health Care Surveys; D006801:Humans; D007362:Intensive Care Units; D006113:United Kingdom; D015032:Zinc / Q000008:administration & dosage* / Q000097:blood* / Q000172:deficiency
chemical_list: D015032:Zinc