Overview
Background
In an acute resuscitation situation, after the airway is secured and adequate breathing and gas exchange are established, the next priority is to obtain vascular access. This is often difficult in infants and children. The physiologic processes of shock and hypothermia with resulting vascular constriction, which are often present in a resuscitative situation, may further complicate the problem; furthermore, the skill and experience levels of providers in caring for small children widely vary.
Intraosseous (IO) access has been used therapeutically since 1934 and has been proved to be a safe, reliable, and rapid means of introducing crystalloids, colloids, medications, and blood products into the systemic circulation.
The marrow cavity provides access to a noncollapsible venous plexus as blood flows from the medullary venous sinusoids into the central venous sinus and is then drained into the central venous circulation via nutrient and emissary veins.
With the development of the intravenous (IV) catheter, the IO needle fell into disuse. In the 1980s, however, IO access was rediscovered as an immediately available tool in resuscitation situations, when time is of the essence and conditions may be adverse.
Since then, IO access has become widely accepted in pediatric settings, especially because these patients often provide a particular challenge to obtaining rapid intravascular access.
A retrospective study by Carlson et al found that in 2011, among out-of-hospital critical procedures provided for pediatric patients by emergency medical services in the United States, IO access was one of the most common. Using the National Emergency Medical Services Information System’s national data set, the investigators found that there were 865,591 emergency medical responses that year involving children. Of 616,913 procedures performed (on 246,016 pediatric cases), 11,026 were critical procedures, the most frequently administered being intubation (3599 procedures, or 6.7 per 1000 pediatric cases) and IO access (2618 procedures, or 5 per 1000 pediatric cases).
Indications
Initiation of IO access is indicated in adults, children, infants, or newborns in any clinical situation where vascular access is emergently needed but not immediately available via a peripheral vein. IO access provides a means of administering medications, glucose, and fluids, as well as (potentially) a means of obtaining blood samples. Such a situation would include any resuscitation; cardiopulmonary arrest; shock, regardless of etiology; life-threatening status epilepticus; or lack of venous access resulting from burns, edema, or obesity.
In comparison with child and infant peripheral IV access, central lines, or umbilical lines, IO access is safer, is associated with fewer complications, can be implemented with less delay, and requires less skill and practice on the part of practitioners who may use the techniques only rarely.
IO needle placement does not constitute definitive therapy; rather, it allows the administration of life-saving medications and fluids in a context where intravascular access is vital. Often, definitive IV access is easier to obtain once a bolus of fluids and medications has been administered via the IO needle.
IO needles may be left in place in the marrow for up to 72-96 hours; presumably, the longer the needle remains in place, the greater the risk of infection and dislodgment. In practice, the needle is usually removed as soon as another means of vascular access (either peripheral or central) is available, ideally within 6-12 hours.
Contraindications
Contraindications to IO access include the following:
Ipsilateral fracture of the extremity, because of resulting extravasation and risk of compartment syndrome
Previous placement or attempted placement in the same leg or site (eg, sternum), because of consequent extravasation into soft tissue compartments through the previous puncture site
Osteogenesis imperfecta, because of the likelihood that puncture of the bone may cause a fracture
Osteopetrosis, because of the risk of fracture
Obvious overlying infection at the proposed puncture site, because of the risk of seeding infection (a relative contraindication)