Intraosseous infusion (IO) is the process of injecting medication, fluids, or blood products directly into the bone marrow; this provides a non-collapsible entry point into the systemic venous system. The intraosseous infusion technique is used to provide fluids and medication when intravenous access is not available or not feasible. Intraosseous infusions allow for the administered medications and fluids to go directly into the vascular system. The IO route of fluid and medication administration is an alternative to the preferred intravascular route when the latter cannot be established promptly in emergency situations. Intraosseous infusions are used when people have compromised intravenous access and need immediate delivery of life-saving fluids and medications. To continue the expansion of knowledge regarding IO administration, a successful blood transfusion took place in 1940 using the sternum, and afterward, in 1941, Tocantins and O'Neill demonstrated successful vascular access using the bone marrow cavity of a long bone in rabbits. Emanuel Papper and others then continued to advocate, research, and make advances on behalf of the IO administration. Once Papper showed that the bone marrow space could be used with comparable success to administer IV fluids and drugs, intraosseous infusion was popularized during World War II to prevent soldiers' deaths via hemorrhagic shock. While popular in the field during WWII, the use of IO was not seen as a standard for emergencies until the 1980s, and only so for children. IO access can provide the quickest way to rapidly infuse needed medications and fluids in an emergency situation.
In addition to the emergency clinical scenario that can call for an IO route to be used, IO access is only indicated when access to peripheral veins is either not possible or delayed. When IV access is either not possible or delayed, other indications for utilizing the IO route include administering contrast if needed for radiology scans and drawing blood for laboratory testing and analysis. Situations that can result in decreased or delayed access to peripheral veins, and thus necessitate the use of an IO route to infuse medications and fluids include circumstances such as burns, fluid accumulation (edema), past IV drug use, obesity, and very low blood pressure.
Contraindications
- Having adequate and timely peripheral venous access is a major contraindication to obtaining IO access.
- Fractures in the bone at the site of device insertion
- Burn damage to the tissues around the site of device insertion
- Cellulitis or other type of skin infection at the site of device insertion
- Osteogenesis imperfecta, also referred to as Brittle Bone Disease
- Osteoporosis
Intraosseous access has roughly the same absorption rate as IV access, and allows for fluid resuscitation. For example, sodium bicarbonate can be administered IO during a cardiac arrest when IV access is unavailable.
Complications include:
- Bone fractures from the puncture devices
- Catheter misplacement which can lead to extravasation
- Bone and tissue damage from the puncturing device needle breaking off in the bone
- Compartment syndrome
Many of these potential complications can be prevented with simple measures like using good technique and keeping the period of IO infusion short by switching to IV as soon as it becomes feasible. Bone fracture complications can be decreased by using modern techniques and requiring more regular training in the methods of intraosseous marrow access for infusion. Extravasation can lead to the more serious complication of compartment syndrome. The risk of developing compartment syndrome can be reduced by medical personnel checking the infusion site regularly for any signs of swelling. Swelling could indicate misplacement of the catheter. Avoiding puncturing the same bone in 48 hours can also lessen the risk of developing this complication. The risk of osteomyelitis, while very low ( <1%), can be further lessened by using sterile, hygienic practices and modern devices to make the puncture. Damage to the epiphyseal plate can be avoided by training medical personnel about proper landmarks to be used for determining puncture sites. A trigger allows for the IO needle to enter the bone marrow space at a preset length without any pressure being applied. In the United States, the FDA has approved the use of the EZ-IO device in the proximal tibia and the head of the humerus.
Intraosseous infusion (IO) is used in pediatric populations during anesthesia when other intravenous access, central venous catherization or venous cutdown, are difficult to use or cannot be used. When individuals are severely ill and need "rapid, efficient, and safe delivery of drugs", IO is used. When inserting the intraosseous needle into a conscious individual, this can be very painful. For children, anesthesia is not recommended before this procedure for non-emergency situations. Instead, distracting and holding the child is preferred. Intraosseous infusion is used in instances such as, "immediate indication/life-threatening emergency, cardiac/respiratory arrest, acute shock, hypothermia, obesity, edema, thermal injury, etc."
For children, the preferred sites of IO are the distal tibia, proximal tibia, and distal femur. The distal end of the tibia is the preferred site because it is easy to access and the most reliable. Depending on the procedure, a variety of needles are used for IO. For example, "standard steel hypodermic, butterfly, spinal, trephine, sternal, and standard bone marrow needles are used." Needles that have a short shaft are preferred and safe. For infants up to 6 to 8 months old, 18-gauge needles are used and for children more than 8 months old, 15- or 16- gauge needles are used.
A study by Glaeser et al., concluded that individuals who received IO vs. peripheral and central intravenous access were able to obtain much faster and more successful IO access. Another study, by Fiorito et al., observed the safety of IO use during the transportation of critically ill pediatric individuals. Based on the results, they concluded that the use of IO was safe, based on 78% successful placement of the IO needle and complications that occurred in only 12% of the cases.
Similarly to adults, contraindications for IO infusion use in pediatrics include bone diseases such as osteogenesis imperfecta and osteopetrosis, and fractures. Others include cellulitis, burns, and infections at the access site.