title: Comparison of first-attempt success between tibial and humeral intraosseous insertions during out-of-hospital cardiac arrest.
abstract: BACKGROUND
  Intraosseous (IO) needle insertion is often utilized in the adult population for critical resuscitation purposes. Standard insertion sites include the proximal humerus and proximal tibia, for which limited comparison data are available.
  
  
  OBJECTIVE
  This study compared the frequencies of IO first-attempt success between humeral and tibial sites in out-of-hospital cardiac arrest.
  
  
  METHODS
  This observational study was conducted in an urban setting between August 28, 2009, and October 31, 2009, and included all medical cardiac arrest patients for whom resuscitative efforts were performed. Cardiac arrest protocols stipulate that paramedics insert an IO line for initial vascular access. During the first month of the study, the proximal humerus was the preferred primary insertion site, whereas the tibia was preferred throughout the second month. The primary outcome was first-attempt success, defined as secure IO needle position in the marrow cavity and normal fluid flow. Any needle dislodgment during resuscitation was also recorded. The association between first-attempt IO success and initial IO insertion location was analyzed using a test of independent proportions and 95% confidence intervals (CIs) for the difference in proportions.
  
  
  RESULTS
  There were 88 cardiac arrest patients receiving IO placement, with 58 (65.9%) patients receiving their initial IO attempt in the tibia. The rate of first-time IO success at the tibia was significantly higher than that observed at the humerus (89.7% vs. 60.0%; p < 0.01). There were 18 initial successes at the humerus; for six (33.3%) of these, the needle became dislodged during resuscitation, compared with 52 initial successes at the tibia, with three (5.8%) dislodgments. The rate of total success for initial IO placements was significantly lower for the humerus (40.0%) compared with that for the tibia (84.5%; p < 0.01) during resuscitation efforts.
  
  
  CONCLUSIONS
  In this subset of patients, tibial IO needle placement appeared to be a more effective insertion site than the proximal humerus. Success rates were higher with a lower incidence of needle dislodgments. Further randomized studies are required in order to validate these results.
authors.affiliation: Department of Emergency Medicine and the Center for Prehospital Medicine and Mecklenburg EMS Agency, Carolinas Medical Center, Charlotte, North Carolina 28232, USA.
authors.forename: Rosalyn
authors.initials: R
authors.lastname: Reades
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Studnek
authors.forename: John S
authors.initials: JS
authors.lastname: Garrett
authors.forename: Steven
authors.initials: S
authors.lastname: Vandeventer
authors.forename: Tom
authors.initials: T
authors.lastname: Blackwell
mesh_terms: D002985:Clinical Protocols; D016001:Confidence Intervals; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D004632:Emergency Medical Services; D006801:Humans; D006811:Humerus; D017148:Infusions, Intraosseous / Q000295:instrumentation / Q000379:methods*; D058687:Out-of-Hospital Cardiac Arrest / Q000628:therapy*; D012042:Registries; D013977:Tibia; D016896:Treatment Outcome