What is the preferred route of intraosseous (IO) access, tibial (in the tibia bone) or humeral (in the humerus bone), in cardiac arrest situations?

From the Guidelines

The tibial route is generally preferred for intraosseous (IO) access during cardiac arrest situations. The proximal tibia, specifically 1-2 cm below the tibial tuberosity on the medial flat surface of the bone, offers several advantages, including ease of identification, minimal overlying tissue, and accessibility during resuscitation 1.

Key Considerations

• The tibial site has a lower complication rate compared to the humeral approach.
• The humeral site (at the greater tubercle) can provide slightly faster flow rates but is more technically challenging to place correctly, especially during resuscitation, and may interfere with ongoing chest compressions.
• Once IO access is established, all medications typically given intravenously during cardiac arrest can be administered through the IO line, including epinephrine, amiodarone, and fluids, with each drug flushed with 10-20 mL of normal saline to ensure delivery into the central circulation 1.

Outcomes

• The use of IO access has been associated with worse outcomes compared to IV access in terms of return of spontaneous circulation (ROSC), survival to hospital discharge, and survival to hospital discharge with a favorable neurological outcome, although the certainty of the evidence is very low 1.
• The IO route is effective due to the bone marrow's vascular network connecting directly to the central venous system, allowing rapid drug delivery comparable to central venous access.

Recommendations

• The tibial route should be the preferred site for IO access in cardiac arrest situations due to its ease of use, lower complication rate, and accessibility during resuscitation.
• Medications should be administered through the IO line with proper flushing to ensure delivery into the central circulation.
• The decision to use IO access should be made on a case-by-case basis, considering the individual patient's needs and the availability of IV access.

From the Research

Comparison of Tibial and Humeral Intraosseous Access

• The studies 2, 3 suggest that tibial intraosseous access has a higher first-attempt success rate compared to humeral intraosseous access in out-of-hospital cardiac arrest situations.
• The study 2 found that individuals randomized to tibial intraosseous access were more likely to experience a successful first attempt at vascular access (91%) compared to those assigned to humeral intraosseous access (51%).
• The study 3 reported a higher rate of first-time intraosseous success at the tibia (89.7%) compared to the humerus (60.0%).

Outcomes with Tibial and Humeral Intraosseous Access

• The study 4 did not detect an association between the first-attempted intra-arrest intraosseous site (tibia vs. humerus) and clinical outcomes, including favorable neurological outcomes and survival to hospital discharge.
• The study 5 found that tibial or humeral intraosseous access as first access strategies in out-of-hospital cardiac arrest were associated with lower odds of return of spontaneous circulation at emergency department arrival compared to peripheral intravenous access.

Comparison with Peripheral Intravenous Access

• The study 2 found that tibial intraosseous access had a higher first-attempt success rate compared to peripheral intravenous access (91% vs. 43%).
• The study 5 reported that peripheral intravenous access was associated with higher odds of return of spontaneous circulation at emergency department arrival compared to tibial or humeral intraosseous access.
• The study 6 found that an intravenous-first approach was associated with improved hospital-discharge favorable neurological outcomes and survival compared to humeral-intraosseous access.