The Intraosseous That Lied: Using Point-of-Care Ultrasound to Confirm Intraosseous Placement in Resuscitation

The 2025 Advanced Cardiac Life Support guidelines recommend intraosseous (IO) access when intravenous access cannot be rapidly obtained. In practice, that often means: “Drill first, ask questions later.” Yet nearly every emergency clinician has a story of an IO that wasn’t actually delivering medications into the medullary cavity, leaving fluids running into soft tissue, joint space, or periosteum while the team assumes access is secured. Adult IO success exceeds 90% in retrospective studies, while pediatric success is lower at 84%. But these statistics mask the failures that matter most: those occurring during high-stakes resuscitations, where a misplaced line silently turns lifesaving drugs into expensive saline tattoos. Although IO access has an excellent safety profile, incorrect placement can cause extravasation, infection, and rare but severe complications such as skin necrosis, fracture, osteomyelitis, and compartment syndrome. Crucially, a malpositioned IO will fail to deliver essential medications and fluids when reliable access is critical. A properly placed IO catheter must traverse cortical bone and terminate within the medullary cavity. Traditional confirmation methods—including marrow aspiration, needle stability, infusion resistance, absence of extravasation, and the ‘squeeze test’—are imperfect. Bone marrow aspiration, often treated like a gold standard, succeeds in only about 68.5% of correctly placed IO lines. So when we “can’t aspirate,” we’re left guessing: is this line bad, or is the test bad? Enter ultrasound. Color Doppler ultrasonography offers a noninvasive approach to confirm IO placement by visualizing flow in response to infusion. Early data are promising but mixed: a small cadaver study of distal tibial IOs (n=8) demonstrated 100% sensitivity and specificity, while a larger swine study of proximal humeral IOs (n=72) reported more modest performance (72% sensitivity, 79% specificity). Notably, diagnostic accuracy tracked strongly with sonographer experience (EM resident < ultrasound fellow < fellowship-trained faculty < ultrasound director), suggesting that inconsistent training—not the tool itself—may be the limiting factor. At present, Color Doppler may be a useful adjunct for experienced sonographers, but it cannot be recommended as the sole confirmation method everywhere. So what’s the practical, scalable alternative? Use ultrasound views we already obtain in resuscitation. A case report described injecting agitated saline through a pediatric IO and confirming placement by visualizing rapid right heart opacification on standard cardiac POCUS windows—no extra imaging workflow, just a smarter use of a familiar view. And if you can’t see agitated saline in the heart or the bone? Ultrasound can still help by directly identifying extravasation into surrounding soft tissue, with reported accuracy around 94% in studied models. Bottom line: if you’re not sure your IO is in the right place, don’t guess—push agitated saline and put a probe on it. We should incorporate IO POCUS confirmation into EM residency training, just as we do for central line and thoracentesis safety checks. The real question isn’t “Can ultrasound do this?” It’s “What’s faster? ultrasound it—or place another IO?” Future directions may include contrast-enhanced ultrasound delivered via IO to confirm both local placement and distal intravascular delivery, while remaining mindful of ultrasound contrast contraindications.