title: Intraosseous access in the obese patient: assessing the need for extended needle length.
abstract: BACKGROUND
  Intraosseous (IO) access can be complicated by obesity. Successful placement of a 25 mm IO needle is unlikely when soft tissue depth exceeds 20 mm.
  
  
  OBJECTIVE
  The authors examined the relationship between body mass index (BMI), the ability to palpate the tibial tuberosity (TT), and soft tissue depth at recommended IO insertion sites.
  
  
  METHODS
  Obese emergency department patients were assessed for a palpable TT and received ultrasound measurement of the soft tissue depth at recommended IO insertion sites. Linear and logistic regression were used to determine cut-off BMI values predicting soft tissue depth >20 mm.
  
  
  RESULTS
  Seventy-five patients were enrolled with a mean BMI of 47.2. The mean soft tissue depth at the proximal humerus, proximal tibial, and distal tibial were 29.6 [95% CI 27.5-31.7] mm, 11.0 [8.9-13.0] mm, and 10.7 [9.4-12.1] mm, respectively. In 5 patients without a palpable TT the soft tissue depth exceeded 20 mm at all three anatomic sites. A BMI ≥43 and BMI ≥60 predicted a soft tissue depth >20 mm at the proximal tibia and distal tibia, respectively, while no reliable BMI cut-off was identified at the proximal humerus.
  
  
  CONCLUSIONS
  In obese adults with a palpable TT or BMI ≤43 a 25 mm IO needle is likely adequate at the proximal and distal tibial insertion sites. Empiric use of an extended 45 mm IO needle is advisable at the proximal humeral insertion site in obese patients.
authors.affiliation: York Hospital, Department of Emergency Medicine, York, PA. Electronic address: tkehrl@wellspan.org.
authors.forename: Thompson
authors.initials: T
authors.lastname: Kehrl
authors.affiliation: York Hospital, Department of Emergency Medicine, York, PA.
authors.forename: Brent A
authors.initials: BA
authors.lastname: Becker
authors.affiliation: Eastern Carolina University, Brody School of Medicine, Department of Emergency Medicine, Greenville, NC.
authors.forename: Dell E
authors.initials: DE
authors.lastname: Simmons
authors.affiliation: Summa Akron City Hospital, Department of Emergency Medicine, Akron, OH.
authors.forename: Erin K
authors.initials: EK
authors.lastname: Broderick
authors.affiliation: MetroHealth Medical Center, Cleveland, OH.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Jones
mesh_terms: D000328:Adult; D001132:Arm; D015992:Body Mass Index; D006801:Humans; D006811:Humerus; D017148:Infusions, Intraosseous / Q000295:instrumentation*; D007866:Leg; D016014:Linear Models; D009339:Needles; D009765:Obesity / Q000000981:diagnostic imaging*; D009767:Obesity, Morbid / Q000000981:diagnostic imaging*; D009929:Organ Size; D040521:Subcutaneous Tissue / Q000000981:diagnostic imaging*; D013977:Tibia; D014463:Ultrasonography