Intraosseous (IO) access is an alternative to conventional intravenous access. The proximal tibia and proximal humerus have been proposed as suitable sites for IO access.

A nonrandomized, prospective, observational study comparing flow rates and insertion success with tibial and humeral IO access in adults using the EZ-IO–powered drill device was conducted. The tibia was the first site of insertion, and a second IO was inserted in the humerus if clinically indicated for the same patient.

Twenty-four patients were recruited, with 24 tibial and 11 humeral insertions. All EZ-IO insertions were successful at the first attempt except for 1 tibial insertion that was successful on the second attempt. All insertions were achieved within 20 seconds. Mean ease of IO insertion score (1 = easiest to 10 = most difficult) was 1.1 for both sites. We found tibial flow rates to be significantly faster using a pressure bag (165 mL/min) compared with those achieved without a pressure bag (73 mL/min), with a difference of 92 mL/min (95% confidence interval [CI]: 52, 132). Similarly, humeral flow rates were significantly faster using a pressure bag (153 mL/min) compared with humeral those achieved without pressure bag (84 mL/min), with a difference of 69 mL/min (95% CI: 39, 99). Comparing matched pairs (same patient), there was no significant difference in flow rates between tibial and humeral sites, with or without pressure bag infusion.

Both sites had high-insertion success rates. Flow rates were significantly faster with a pressure bag infusion than without. However, we did not find any significant difference in tibial or humeral flow rates.