R.E.B.E.L.EM - January 9, 2017 - By Anand Swaminathan
Peer Reviewed By: Salim Rezaie
"Background:
Intraosseous (IO) access can play an important role in the resuscitation of the critically ill patient to help expedite delivery of critical medications (i.e. RSI). Much like with peripheral or central access, obesity can present a challenge to placement of an IO as accurate placement relies on use of landmarks which may not be palpable in this group. Additionally, increased soft tissue depth may render standard needles ineffective. IO needles require 5 mm of excess length from skin to bony cortex to ensure successful placement (i.e. maximal depth of 20 mm for a 25 mm needle). Studies investigating these questions are necessary in order to understand how reliable IO access will be in obese patients.
Author’s Conclusions:
“In obese adults with a palpable TT or BMI ≤43 a 25mmIO needle is likely adequate at the proximal and distal tibial insertion sites. Empiric use of an extended 45mmIO needle is advisable at the proximal humeral insertion site in obese patients.”
Potential Impact to Current Practice:
In obese patients, it is reasonable to reach for the 45 mm IO needle instead of the 25 mm needle to ensure adequate length to obtain access. The 45 mm IO needles can be used at any site regardless of depth as long as the provider does not “bury the needle.” Placement until the needle penetrates the cortex (possibly leaving some portion of the needle protruding from the skin) will provide IO access at all three common sites.
Bottom Line:
The 25 mm IO needle may not provide proper length for obtaining IO access in obese patients. Consider reaching for the 45 mm IO needle in these patients particularly if you cannot palpate the tibial tuberosity."