The potential use of intraosseous (IO) infusions for adults was first examined 80 years ago. Until very recently, this procedure was most commonly considered a rescue technique for pediatric patients, and then only after all else had failed. However, the use of IO access is making a comeback! Once again, it is being recognized as a valuable adjunct to adult, as well as pediatric, fluid and medication administration. This change has taken place primarily as a result of increasing recommendations to more rapidly consider the IO route, extend usage beyond our youngest patients and evaluate the potential of new and improved devices.
This article reviews the indications for pediatric and adult IO placement, addresses many of the concerns associated with the procedure and introduces several new devices available for this potentially lifesaving technique.
Intraosseous infusion is "an effective, reliable and relatively simple technique, both for obtaining rapid vascular access and for the administration of fluids and medications in the emergency setting."1
It is well known that establishing intravenous access in an infant or young child is challenging even under normal circumstances.2 In the prehospital and emergency department settings, few things provoke generalized apprehension like the need to place an intravenous line in a critically ill child. Experienced nurses and paramedics know that it is hard enough to start an IV on a healthy child, not to mention one who is sick or injured. To make matters worse, add the effects of vasoconstriction to naturally small veins, and the result is a situation that most providers would simply describe as a nightmare.
Although a potential solution for this problem was first suggested over 80 years ago, it was generally restricted to resuscitating critically ill children. Since the 1920s, it has been recognized that the bone marrow functions as a "non-collapsible" vein and is able to provide a route for rapid vascular access.3,4 This medical breakthrough had important applications, especially for pediatric resuscitation, because children may not seem to have veins, but they always have tibias. Recent developments have made IO access an even more important tool in our arsenal of available options that can be used for the sickest kids and adults as well.
Despite widespread use of venous catheters, it is recognized that potential major limitations of prehospital resuscitation relate to time delays and failure rates associated with obtaining vascular access.4
IV access provides a "lifeline" for critically ill or injured patients. In both the EMS and ED arenas, the time needed to obtain that lifeline is the key. Placing an IV in an adult in a moving ambulance can take 10--12 minutes, with a 10%--40% failure rate.5 Studies of pediatric IV attempts by EMS providers have shown that as many as one-third of IV attempts took longer than five minutes to complete and one-fourth took longer than 10 minutes. In 6% of the attempts, there was complete inability to obtain IV access.6--8 With time being such an important consideration, we can compare these results with studies showing a 70%--100% success rate for pediatric and adult intraosseous placement, often within one minute.9--11
Shock, Blood Flow and Bones
A brief review of shock and blood flow may be helpful in understanding the potential of intraosseous infusion. In shock, blood is shunted to the "core" organs, namely the heart, lungs and brain, and away from the periphery (including our favorite IV sites). The body is saying, "What do I really need to stay alive right now? Heart, lungs and brain. What do I not need? Everything else." This self-protective mechanism makes peripheral intravenous access, even in the most skilled hands, difficult, if not downright impossible. In contrast with the peripheral vasculature, the intraosseous space--a rich network of blood vessels within the bone--remains unchanged by the effects of shock. Though the peripheral veins are "clamped down," access to blood flow through the "non-collapsible veins" remains an option in infants, children and adults.9,12