title: Analysis of intraosseous samples using point of care technology--an experimental study in the anaesthetised pig.
abstract: BACKGROUND
  Intraosseous access is an essential method in emergency medicine when other forms of vascular access are unavailable and there is an urgent need for fluid or drug therapy. A number of publications have discussed the suitability of using intraosseous access for laboratory testing. We aimed to further evaluate this issue and to study the accuracy and precision of intraosseous measurements.
  
  
  METHODS
  Five healthy, anaesthetised pigs were instrumented with bilateral tibial intraosseous cannulae and an arterial catheter. Samples were collected hourly for 6h and analysed for blood gases, acid base status, haemoglobin and electrolytes using an I-Stat point of care analyser.
  
  
  RESULTS
  There was no clinically relevant difference between results from left and right intraosseous sites. The variability of the intraosseous sample values, measured as the coefficient of variance (CV), was maximally 11%, and smaller than for the arterial sample values for all variables except SO2. For most variables, there seems to be some degree of systematic difference between intraosseous and arterial results. However, the direction of this difference seems to be predictable.
  
  
  CONCLUSIONS
  Based on our findings in this animal model, cartridge based point of care instruments appear suitable for the analysis of intraosseous samples. The agreement between intraosseous and arterial analysis seems to be good enough for the method to be clinically useful. The precision, quantified in terms of CV, is at least as good for intraosseous as for arterial analysis. There is no clinically important difference between samples from left and right tibia, indicating a good reproducibility.
authors.affiliation: Section of Anaesthesiology & Intensive Care, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden. Gunnar.Strandberg@surgsci.uu.se
authors.forename: Gunnar
authors.initials: G
authors.lastname: Strandberg
authors.forename: Mats
authors.initials: M
authors.lastname: Eriksson
authors.forename: Mats G
authors.initials: MG
authors.lastname: Gustafsson
authors.forename: Miklós
authors.initials: M
authors.lastname: Lipcsey
authors.forename: Anders
authors.initials: A
authors.lastname: Larsson
mesh_terms: D000758:Anesthesia; D000818:Animals; D001842:Bone and Bones; D005260:Female; D019095:Point-of-Care Systems; D013048:Specimen Handling / Q000379:methods*; D013552:Swine