Distal Femur Intraosseous Access Is Equivalent to Humeral, Tibial or Intravascular Access

Introduction—Vascular access is an integral component of prehospital resuscitation. Medications and fluids may be beneficial for some patients in cardiovascular collapse, yet access is often difficult in this population. Currently the EZ-IO system is cleared by the FDA to access either the humerus or tibia. The authors recently began educating both EMTs and paramedics to access the distal femur during circulatory arrest resuscitation. The objective of this study was to evaluate if accessing the distal femur was equivalent to the proximal humerus or tibia.

Methods—This was a retrospective analysis of prospectively collected data abstracted from the cardiac arrest registry maintained by the office of the medical director from a large urban EMS system. The cohort consisted of all resuscitation attempts. Choice of vascular access was at the discretion of the EMT or paramedic; options included proximal tibia, proximal humerus, distal femur or peripheral IV. Primary single variable outcomes were successful placement (defined as: stable in positon, flowing, with no evidence of extravasation) and return of spontaneous circulation (ROSC). Secondary outcomes were pulse on arrival to the emergency department and complication rate (dislodgement, lack of flow or extravasation).

Results—During the nine-month period, there were 780 attempted resuscitations. Of these, the distal femur, proximal humeru, and proximal tibia were utilized 35 (5%), 500 (64%) and 128 (16%) times, respectively. The proximal humerus and distal femur first-attempt placement rates exceeded 95%, whereas the tibia rate was 87%. There was no difference in complication rates; all were less than 10%. ROSC rates ranged from 26% (tibia) to 36% (humerus), with no significant difference compared to the distal femur (34%). Pulse on arrival to the hospital was also statistically indifferent. Total average fluid administration during resuscitation ranged from 480±284 ml (humerus) to 361±240 ml (tibia) and was in both cases not different to the femur (431±210ml).

Conclusion—The distal femur did not differ from proximal humerus or proximal tibia for any outcomes measured. The distal femur may be favorable for select situations. The authors speculate the femur’s anatomic location is less obstructive to the choreography of resuscitation.