E Z - I O UPDA T E f or DA S
The use of intraosseous (IO) access devices has become a vital
tool in the pre-hospital environment over the last 4-5 years. In
situations where intravenous access is difficult or unable to be
obtained, IO access is able to provide a route for fluid and
medication administration. This course will review the use of
the EZ-IO system, including indications, contraindications, and
the “6 Rights” of the EZ-IO. Content of this course is based on
the current recommendations from Vidacare and the current
Region 5 protocols.
ANATOMY REVIEW
Classification of bones:
There are 206 named bones comprising the human skeleton. Bones are classified by their
shapes either long, short, flat, or irregular. Long bones are named for their overall shape, not
their overall size. The phalanges are considered long bones even though they are quite short.
Long bones are longer than they are wide consisting of a shaft and two ends. The shaft of the
bone is called the diaphysis. This forms the long axis of the bone. It is formed from a thick layer
of compact bone that surrounds a medullary or marrow cavity. The epiphyses are the bone
ends. They are often more expanded that the diaphysis and contain spongy bone. All limb
bones excluding the bones of the wrists and ankles are long bones.
Short bones are roughly cube shaped. Examples include the bones of the wrists and ankles.
Sesamoid bones are special types of bones that form within tendons. The patella is an example.
The function of some sesamoid bones is to alter the direction of the pull of a tendon. Flat bones
are thin and somewhat curved. Examples include the sternum, scapulae, ribs, and bones of the
cranium. Irregular bones have complicated shapes that do not fit in the other classes. We will
focus our attention on the long bones.
Every bone has a dense outer layer of compact bone which surrounds spongy or cancellous
bone. Spongy bone is a honeycomb of osseous spicules called trabeculae. Within the spaces of
the trabeculae is red or yellow bone marrow.
The humerus:
Focusing our attention on the proximal humerus, there is a smooth hemispherical head which
articulates with the scapula so that it hangs freely to one side. Immediately inferior to the head
is a slight constriction called the anatomical neck. Inferior to the anatomical neck are the
laterally positioned greater tubercle and the medially positioned lesser tubercle. Separating the
tubercles is the intertubercular sulcus. This sulcus guides the biceps tendon to its attachment
point. It also houses a branch of the humeral circumflex artery. Just distal to the tubercles is the
surgical neck, so called because it is the most frequently fractured site of the humerus. See the
picture below for reference.
The tibia:
The tibia recieves its weight from the body via the femur and trasmits this weight to the foot. It
is second only to the femur is size and strength. At its proximal end are the lateral and medial
condyles. These articulate with the corresponding condyles of the femur. These condyles are
spearated by the intercondylar eminance. Inferior to the condyles on the anterior surface of the
tibia is the tibial tuberosity, to which the patellar ligamnet attaches. The shaft of the tibia is a
tirangular shape. Neither its anterior border or its medial surface are covered with muscles.
They can easily be palpated just deep to the skin over its entire length. Distally, the tibia is flat
where it articulates with the talus bone of the foot. Medial to that joint is a projection called
the medial malleolus. See the picture below for reference.
I N DI C AT O NS:
Intraosseous access is indicated for adults (≥ 40 kg) and pediatric patients (3-39 kg) anytime
vascular access cannot be established after two attempts or 90 seconds. The patient must also
be experiencing one or more of the following:
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altered mental status
respiratory compromise
hemodynamic instability
status epilepticus refractory to IM medication administration.
If IV access is not readily available, IO access may be considered prior to any IV attempts in the
following situations:
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medical or traumatic cardiac arrest
signs and symptoms of hypoperfusion (profound hypotension, tachycardia and altered
mental status)
a patient in extremis needing IMMEDIATE medication administration
C O N T RA INDI CAT IO NS:
The use of the EZ-IO device is contraindicated, and an alternate site should be considered, in
the following situations:
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Fracture to the target site (proximal, distal tibia or proximal humerus)
Previous orthopedic procedure (i.e. knee replacement) to target site
Prosthetic limb or joint
Intraosseous access within the past 24 - 48 hours at the target site
Infection at the insertion site
Inability to locate landmarks or excessive tissue over the insertion site

History of osteogenesis imperfecta
Region 5 protocol limits the use of the EZ-IO system to pediatrics above 3 kilograms. Vidacare
recommends that a manual IO device (e.g. Illinois needle) be used if a pediatric patient is less
than 3 kilograms. Region 5 protocols do not offer any recommendations in such a case. It is
suggested that on-line medical direction be consulted.
THE SIX RIGHTS OF THE EZ-IO
Vidacare had developed the “Six Rights” of the EZ-IO in order to help providers remember key
items to successful placement. These Six Rights are:
1.
2.
3.
4.
5.
6.
Right Assessment
Right Site
Right Needle
Right Flush
Right Comfort
Right Monitoring
When these Six Rights are followed, proper placement and flow are more likely to be achieved.
We will look at each item in detail.
T HE RI G HT A SSE SS ME NT
When to use the EZ-IO:
The EZ-IO can be used for adult and pediatric patients anytime when vascular access is difficult
to obtain in emergent, urgent, or medically necessary situations.
A common misunderstanding of IO access is that it takes a long time for fluids, medications, or
blood infused to reach the central circulation. This is false. Scientific studies have proven any
fluid infused into the intraosseous space enters the central circulation within just a few
seconds.
The EZ-IO is an immediate option that can serve as your main line. It may also serve as a bridge
to peripheral, PICC or central venous access. In accordance with Region 5 protocols, providers
should assess the patient and consider using the EZ-IO after two attempts at IV access or 90
seconds have elapsed trying to establish IV access or when a patient exhibits signs and
symptoms of:
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Altered mental status
Respiratory compromise
Hemodynamically unstable

Status epilepticus refractory to IM medication administration
Other considerations include the following:
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Patients with minimal risk factors (discussed later)
The need for vascular access in less than 10 seconds to allow for proper pharmacology
administration
A patient requiring large fluid volume infusions
Such presentations include but are not limited to:
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Shock trauma
Cardiac resuscitation, arrhythmia, myocardial infarction, congestive heart failure, or
chest pain
Hypothermia
Neurological - status epilepticus, stroke, coma, head injury
Respiratory - respiratory arrest, status asthmaticus
Hematologic – systematic hemophiliac crisis, sickle cell crisis
Metabolic crisis - DKA, diabetic shock
Circulatory crisis – dehydration, end stage renal disease, dialysis
Once the decision is made to gain IO access, assess the chosen site for any of the following five
site contraindications for using EZ-IO at that location:
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Prosthesis or previous orthopedic procedures near the insertion site: An easy rule of
thumb to use is if the patient has a surgical scar over a joint; assume there is a titanium
appliance within the joint. DO NOT USE THE EZ-IO at that location. The EZ-IO needle
sets cannot penetrate titanium. Simply move to another FDA and/or Region 5 approved
insertion site and assess that site for use.
Trauma or Fracture (in the target bone): If there is a fracture (or suspected fracture) in
the bone in which the EZ-IO is to be placed, an alternate site must be chosen. Fluid will
follow the path of least resistance. When an IO is placed in a fractured bone, the fluid
will extravasate into the surrounding tissue through the fracture. This can lead to
complications including compartment syndrome. If a tibial fracture is suspected, both
the proximal and distal sites will be contraindicated as they share the same common
pathway inside the bone. However, if the patient has a fractured femur but an intact
tibia, the tibial sites COULD be used as they are totally separate bones. The circulation
from lower leg should be assessed to judge the appropriateness of using the lower
extremity for EZ-IO.
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Inability to locate landmarks (e.g. due to excessive tissue): If the clinician is unable to
locate the landmarks for an insertion site for any reason (including excess adipose
tissues), select an alternate insertion site where you can identify the bony landmarks.
Infection at the insertion site: Vidacare and Region 5 do not recommend inserting the
EZ-IO through any visible or documented infection or inflamed region at the insertion
site.
IO access within past 48 hours (in the target bone): Healing from IO insertion generally
takes 48 hours and is defined as the point where another IO can be safely placed at the
same anatomical site. By that time, fibrin formation and clotting are sufficient to
prevent extravasation through the previous IO puncture. Complete healing, to the point
where X-ray can no longer detect the hole, usually takes several days or weeks.
These five safety limitations are critical assessment considerations prior to insertion of an IO
device.
T HE RI G HT SIT E
Once you have decided that a patient will benefit from the EZ-IO, the first step is to identify the
right site for needle placement. The FDA has approved three sites that the EZ-IO can be placed:
the proximal humerus, proximal tibia, and the distal tibia. Note that the Region 5 protocols do
not list the proximal humerus as an insertion site. It is important to properly locate these sites
to ensure successful insertion.
Pr o x i mal Hu mer u s :
The greatest advantage of using the humeral site is flow rate. The close proximity of the greater
tubercle of the humerus to the heart ensures rapid infusion of medications into the central
circulation. Average flow rates of five liters per hour can be achieved using the humeral site.
The proximal humerus has been reported as being less painful site to access compared to either
of the tibial sites. This is also the preferred site for patients who are responsive to pain.
The proximal humerus insertion site is located directly on the most prominent aspect of the
greater tubercle. To properly landmark this site, ensure that the patient’s hand is pronated
(palm down) and resting on the umbilicus. The elbow must be adducted (close to the body).
This ensures that the intertubercular sulcus is rotated medially protecting the structures within.
Slide your thumb up the anterior shaft of the humerus until you feel the base of the greater
tubercle, this is the surgical neck. Approximately 1 cm above the surgical neck is the insertion
site. Access the link below to watch a video on how to properly landmark this site as well as live
insertions.
https://www.youtube.com/watch?v=Wu-KVibUGNM
Pr o x i mal T i bi a
Adults: The proximal tibia insertion site is approximately 2 cm below the patella and
approximately 2 cm medial to the tibial tuberosity. Remember: “Big Toe IO” means to look on
the big toe side of the leg for the tibial plateau (the flat spot). Flow rates ranging from 350 mL –
3300 mL per hour within pressures of 300 mmHg have been achieved in the proximal tibia.
Pediatrics: The pediatric insertion site at the proximal tibia is the same for adults. The tibial
tuberosity is not palpable on infants and some small children less than two years old. The
proximal tibia insertion site in pediatrics is approximately 2 cm or 2 fingerbreadths below the
patella and approximately 1 cm medial to the tibial tuberosity. In small children, generally
under the age of two, if the tibial tuberosity cannot be palpated, locate the distal aspect of the
patella, move approximately 2 cm distally and then medially to the flat aspect of the tibia.
Di s t al T ib i a
The distal tibia insertion site is located approximately three centimeters or three fingerbreadths
proximal to the most prominent aspect of the medial malleolus. Place one finger directly over
the medial malleolus; move approximately 3 cm proximal and palpate the anterior and
posterior borders of the tibia to assure that your insertion site is on the flat center aspect of the
bone. Again; “Big Toe IO”. Note: for pediatric patients, the distance is less.
T HE RI G HT NEE DLE
Selecting the proper needle is just as important as selecting the site. EZ-IO needles come in
three sizes: 15mm (pink), 25mm (blue), and 45mm (yellow). All three needle sets are 15 ga
needles. A common misconception is that the patient’s age should be the lone deciding factor
when selecting the proper length of needle. Instead of age, the amount of tissue at the
insertion site should be used to determine the correct length of needle. One way to determine
the depth of tissue is to palpate the insertion site with your finger or thumb. If there is a small
amount a tissue, like that over your knuckle, a shorter needle will be needed. If the tissue depth
is excessive, similar to pressing your finger or thumb over the femur, then a longer needle is
needed. The 45mm needle is recommended as the primary set for proximal humerus site for
patients over 40kg (90lbs).
Another way to confirm proper needle selection is by using the 5mm mark on the EZ-IO needle
set. With the needle attached to the driver, insert the needle through the skin until the tip rests
against the bone at a 90 degree angle. Look at the needle to assure that you can visualize at
least one black line above the surface of the skin. If you cannot see a black line, the needle set
selected is too short to reach the medullary space appropriately. Remove the current needle
set, discard and use the next larger size. See the picture below for reference.
Pr o p er i n sert i on
Please note that with all patients, minimal pressure should be placed on the driver during
insertion. This is especially true with pediatric patients. With softer and smaller bones, special
care must be taken during insertion to avoid excessive pressure and recoil. Recoil can occur
when the clinician feels the lack of resistance upon entry into the medullary space and
inadvertently pulls back on the driver. This recoil may displace the needle set from the
medullary space.
After ensuring the proper site and the proper needle, it is now time to insert the EZ-IO needle.
First assemble all of the required components. This includes the EZ-IO driver, selected needle
set, Betadine swaps or alcohol preps, 2% lidocaine, and saline flushes. Inspect the needle set
ensuring all the components are present and not damaged. Open the EZ-Connect tubing and
prime the extension set with 2% preservative free Lidocaine, if the patient is conscious. If the
patient is allergic to lidocaine or is unconscious, prime
the extension set with 0.9% normal saline. In either case,
leave the syringe attached. Next clean the selected site
with copious amounts of Betadine or alcohol preps.
Betadine is preferred if available provided the patient is
not allergic to iodine products. If time permits, the site
should be swabbed three separate times in ever
increasing outward circles using a fresh swab each time.
Attach the needle set to the driver, this is held in place
by a magnet in the needle. Remove the cap from the needle set by holding the cap and briefly
activating the driver. This will unseat the cap and allow for easier removal. Insert the needle
through the skin at a 90 degree angle until you feel the tip of the needle touch the bone. Verify
that at least one black line is visible. Stabilize the extremity with your non-dominant hand. Hold
the needle over the exact location and angle you plan to insert with. Gently and BEFORE
PULLING THE TRIGGER, insert the needle set through the skin until you feel the tip of the needle
touch the outer surface of the bone. Now, squeeze the trigger and apply gentle, steady
pressure to insert needle. Let the driver cut through the bony cortex while continuing to hold
the trigger ON.
Once the insertion is completed secure the extremity to prevent movement and accidental
dislodgement of the IO catheter.
Adult: Be sure to “drive” the needle all the way thru cortex until the needle is seated with the
hub flush against the skin. For the proximal humerus specifically, Vidacare recommends the 45
mm needle (yellow) on patients > 40 kilograms. Angle the needles set at 45 degrees to the
anterior plane of the body and advance the needle in a posterior-medial direction (See picture
below). Region 5 makes no recommendation for the use of the proximal humerus as an access
site. Advance the needle set approximately 1 cm after contact with bone or after entry into
medullary space. In the humeral site, the needle set should be advanced until catheter hub is
against the skin. When using the proximal humerus, it is recommended the catheter is
stabilized using the EZ-IO stabilizer.
Pediatrics: Stop immediately when you feel the resistance change. This indicates entry into the
medullary space and avoids penetrating the full thickness of the bone.
ALWAYS USE CARE to ensure you have selected the appropriate size needle set based on
tissue depth and when inserting past the sensation of pressure change or loss of resistance.
While holding the hub, pull the driver away from the needle, unscrew (counter clockwise) the
needle from the hub and remove it, and immediately place the needle into the sharps box.
Attach the EZ-Connect tubing to the needle.
Confirmation of proper placement of the needle into the medullary space can be done several
ways. Aspiration of marrow and/or blood into the EZ-Connect tubing can be used however,
aspiration may not always occur, even if the EZ-IO needle has been placed properly. The
absence of marrow/blood does not mean an unsuccessful placement. A firmly seated, stable
needle and the ability to administer pressurized fluids without difficulty are indicators of
successful placement. After insertion, check the following:
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That the needle is firmly seated
Attempts to aspirate for blood or bone marrow were made
There is no leaking around the site
There are no indications of extravasation
Secure the site using the provided EZ stabilizer and place the EZ-IO wrist band on the patient.
T HE RI G HT FLUSH
One of the most common mistakes made in IO placement is not properly
flushing the IO site prior to administering fluids and/or medications. The
intraosseous space is filled with a marrow that is held in place by a thick
fibrin mesh. This fibrin mesh must be displaced in order to achieve
optimal flow. The EZ-IO must be flushed rapidly with 10mL of saline to
displace the fibrin network. The flush may have a similar sensation as
pushing D50 through an IV site. Region 5 protocol recommend that the
site be flushed with 20-50 mg of 2% preservative free Lidocaine for
adults and 0.5 mg/kg for pediatrics. This flush is to be followed by a 10
mL flush of 0.9% normal saline for adults and a 5 mL flush for pediatrics.
After flushing, the IO should flow easily and rapidly. Occasionally,
additional saline flushes may be needed. If an IO site is not flowing properly, flush the site with
another 10 mL saline flush to see if flow improves. Remember: NO FLUSH = NO FLOW.
E n s u ri n g op ti mal f lo w r at es
The final step in ensuring successful EZ-IO insertion is using the right amount of pressure to
maintain proper fluid flow. The pressure inside the medullary space is approximately one-third
that of the patient’s mean arterial pressure (systolic BP + 2(diastolic BP)/3). In order to achieve
the best flow rate, the pressure of the fluids in the IV bag being administered must be higher
than the pressure in the medullary space. Using a pressure infuser is the easiest way to increase
fluid pressure. A blood pressure cuff may be used in lieu of a pressure infuser.
T HE RI G HT CO MFO RT
It is a misconception that insertion of the EZ-IO needle is the
most painful part of the procedure. Many patients and
volunteers noted that the pain from insertion is similar to
that of insertion of an 18ga IV needle. The majority of the
pain associated with IO insertion comes from the increased
pressure inside to medullary space during fluid
administration.
One of the advantages of IO access is the fact that the
medullary space is a non-collapsible space, but it is also non-expandable. When fluid is
introduced in to IO space, pressure is placed on the visceral nerve endings causing pain. Proper
pain management is an important part of using the EZ-IO system. Remember, many of the
procedures we doing routinely cause pain, how we treat the discomfort is as important as the
procedures. If a patient is responsive to pain, administration of 40mg (2mL) 2% preservative
free Lidocaine, prior to flushing with saline will help reduce the pain associated with increased
pressure in the medullary space. Lidocaine provides a local anesthetic effect to the area of
insertion. In order for this to happen, the administration must be done slowly, over 15-30
seconds.
T HE RI G HT MO NI T ORI NG
Regular, periodic assessment is essential for safe IO access management. As a general rule, do
what you would normally do with a peripheral IV site in terms of assessment, site care, flow
rate intervention, and medication use. Verification of placement before each infusion is
recommended.
Ensure the site is intact on each assessment visit, the needle is securely in place, the patient
identifiers are in place, the patient is comfortable and of course, the EZ-IO is working optimally.
The EZ-IO must be removed 24 hours from the time of insertion.
Remo vi n g E Z - I O Need l e
The EZ-IO needle must be removed from the patient within 24 hours. To remove the EZ-IO
needle from the patient, first clamp the EZ-Connect tubing and disconnect it from the EZ-IO
needle. Attach a lure lock compatible syringe to the EZ-IO needle; this is used as a handle to aid
in removal. Rotate the syringe and needle clockwise, to release the needle from the cortex, and
pull straight out while continuing to rotate clockwise. DO NOT ROCK THE NEEDLE BACK AND
FORTH. After rotating several times the needle should come completely out. There may by
minor bleeding at the insertion site. Clean and dress the insertion site with an adhesive
bandage or similar dressing. The EZ-IO needle must be removed from the patient within 24
hours.
Havi n g I s su es ?
If you ever have questions or problems with the EZ-IO system,
Vidacare provides a 24 hour “hot line” to assist with clinical
issues. In every EZ-IO needle set there is a fluorescent colored
wrist band that should be attached to the patient. This wrist band
alerts the receiving staff that the patient has an IO in place and
when it was place. The 1-800 “hotline” number is also on the
wrist band.
The placement of an IO needle can be both safe and beneficial for patients in need of emergent
vascular access. Remember the Six Rights of EZ-IO Placement:
1.
2.
3.
4.
5.
6.
Right Assessment
Right Site
Right Needle
Right Flush
Right Comfort
Right Monitor
REFERENCES:
BCMS. EZ-IO Update for Buncombe County EMS [Web page]. Retrieved from
http://emsstaff.buncombecounty.org/inhousetraining/ez_io_Update/ez_io_overview.htm
Hoehn, K., Marieb, E. (2007). Human Anatomy and Physiology 7th Edition. 178-180, 231-232,
242-244.
Vidacare. The Clinical Principles of Successful Intraosseous Vascular Access [Powerpoint
presentation]. Retrieved from: http://www.teleflex.com/en/usa/ezioeducation/EZ-IO-Clinical-PrinciplesNo-Vid-2014-2780.pptx.
Vidacare. Clinical Principles to Successful IO Insertion EZ-IO Six Rights 5-30-12 (1) [Powerpoint
presentation]. Retrieved from: www.teleflex.com/en/usa/ezioeducation/EZ-IO-Clinical-PrinciplesNo-Vid-2014-2780.pptx
Region 5. (2013). Region 5 Paramedic Protocols