Intraosseous catheter confirmation with central venous color flow and doppler waveform, a randomized single-blinded trial

Obtaining intraosseous (IO) access is an established procedure within the critical care setting. Mechanisms for routinely confirming IO placement and sustained IO efficacy lack objectivity, fail to incorporate modern technology, and lack protocol advancement that improves patient treatment, safety, and provider confidence. In this study, we investigate the novel use of color and doppler point-of-care ultrasound (POCUS), in combination with an IO fluid bolus, as a potential means to confirm IO placement. Design: randomized single-blinded comparison using doppler and color flow to confirm proximal central venous flow during IO infusion. Study model: fresh, never frozen, unembalmed, and consented cadavers. Standard arm: intentionally correct IO placement randomized across the proximal humerus, distal femur, and proximal tibia. Comparison arm: intentionally incorrect IO placement. Protocol: Following access confirmation, an IO fluid bolus was initiated. An operator, blinded to the correct versus the intentionally incorrect IO placement, applied POCUS to the central vein proximal to the established IO catheter. POCUS, in concert with a fluid bolus, was then used to assess for color flow and the generation of a doppler waveform at the associated proximal central vein. The operator additionally applied POCUS to assess the IO insertion site and extremity for the presence of extravasation. The unblinded operators identified proximal venous color flow and doppler waveform in 100% of intentionally placed IOs, while the blinded POCUS operator identified them in 86% and 88% of cases with correctly placed IOs. 7% intentionally misplaced IOs generated doppler waveform and color flow, ultimately determined on post-procedure dissection to be secondary to an inadvertent cannulation of a deep peripheral vein adjacent to the bone. On average, correctly placed tibial IOs required more volume to produce color and doppler flow than humoral IOs. The ability to accurately confirm and reassess IO catheter placement and patency is of vital importance throughout the entire critical care continuum. Awareness of procedural POCUS specific to the use of color flow and doppler waveform to confirm IO placement may provide additional assurance that an IO catheter has been successfully placed, remains in position, and is functioning safely.