Pediatrics 12: Intraosseous Vascular Access
PEDS: Because this entire portal pertains only to pediatric patients, the convention of underlining has been omitted.
The
establishment of an intravenous line in an injured or critically ill
infant or young child may be very difficult or impossible. This may
delay the administration of critically needed fluids or medications.
The intraosseous approach is a useful technique of gaining vascular
access within a couple of minutes or fewer and may be lifesaving.
Intraosseous
infusion is the establishment of an intravenous infusion into the bone.
Long bones contain cavities called medullary or marrow cavities, which
are a spongy network of venous sinusoids that drain into a central
venous canal.
These central venous canals drain via emissary veins into the general circulation.1 Fluids and medications injected into these marrow cavities are rapidly picked up by these blood vessels and carried into the central circulation. The intraosseous acts as a non-collapsible vein and permits access into the central circulation as rapidly as any peripheral vein. These veins will not even collapse during shock.2
Any site that contains marrow is a potential site for intraosseous infusions. Sites include the distal femur greater trochanter, anterior tibial plateau, sternum, medial and lateral malleoli, os calcis, and the anterior superior iliac spine.2 The intraosseous is not meant to be used as a definitive method of intravenous access and should not be used for more than 12 hours.
Indications for the Use of the Intraosseous Infusion
The
intraosseous is considered for use when a patient needs medications or
volume expansion and an IV is unable to be started on a timely basis.
Also, it is risky or not possible to start a central line by subclavian
or internal jugular technique, and the endotracheal route will not
allow the delivery of the medications or fluids.
Clinical indications to consider placing an intraosseous in children include:
- Shock with vascular collapse
- Cardiac arrest
- Severe dehydration
- Status epilepticus
- Massive trauma or major burns
- Edema or obesity in small children
- Loss of normal veins due to previous intravenous therapy
- Intravenous drug abuse
In such cases, time is crucial. If a peripheral line cannot be started in 2 attempts or in fewer than 90 seconds, clinicians should consider starting an intraosseous line.3
Site Selection for Intraosseous Insertion
In
children younger than 6 years, the sites most readily available and
preferred for use4,5 are (1) the proximal flat-broad tibial plateau, 1
to 2 finger breadths (1 to 2 cm) below the tibial tubercle on the
anteromedial surface and (2) the distal femur, 2 to 3 cm above the
external condyles in the midline. The bone cortex is easily penetrated
in patients up to 6-years-old. After 6 years of age, the cortex becomes
progressively thicker and harder to penetrate. In older children the
medial distal tibia, 1 to 2 finger breaths proximal to the medial
malleolus and sufficiently posterior to avoid the saphenous vein, may
be used.1,5 Be sure to avoid the epiphyseal plates of the distal femur
or the proximal and distal tibia.2 (Figure 1) Other indications to
avoid in the use of the intraosseous needle include recent fracture to
the extremity, infected burns or cellulitis, osterogenesis imperfecta,
and osteopetroses.2
Insertion of the Intraosseous Needle
The
easiest method of intraosseous access is the EZ-IO. If this is not
available, use an intraosseous needle with a stabilizing guard, such as
the 16-gauge Illinois Sternal Iliac Aspiration Needle made by Sherwood
Medical (both pediatric and adult).
A smaller size such as the 18-gauge Jamshidi needle (made by Dyna Med) is available for neonates and infants.
Insertion of the Intraosseous Needle into the Proximal Tibia
- Identify the site for puncture. The flat anteromedial surface of the tibia one- to two-finger breadths below the level of the tibial tuberosity is the preferred site.
- Position the leg with the knee slightly bent and semi-externally rotated. Place a sandbag or towel roll under the leg for support.
- Prepare the site with povidine solution.
- Place the hub of the intraosseous needle handle in the palm of your hand and place your index finger on the shaft. Insert it firmly through the skin onto the tibia. When the needle is resting against the tibia, turn down the needle guard until it is approximately 1/4 inch from the skin.
The needle guard is placed so that the needle does not penetrate too far. The alignment of the needle, wrist, and elbow in a straight line gives the operator better control of the needle while increasing strength. (Figure 4)
Hold the leg with your non-dominant hand behind the leg at the level of puncture. Raise your elbow so that the needle held in the palm of your dominant hand forms a straight line with your wrist and elbow. The needle should be at right angles to the skin. Placing your arm in this position allows you to turn the needle as you push it into the bone without wobbling and sliding off of the bone.
- Push and turn the needle with a twisting type motion until the guard rests against the skin. You will usually feel a give as the needle enters the marrow cavity.
- Indications of successful
intraosseous insertion include2,3:
- An obvious pop or give as the needle enters the marrow cavity.
- An obvious pop or give as the needle enters the marrow cavity.
- The needle will feel firmly fixed by the bone and stand upright without support.
- Remove the needle trocar and check for placement by injecting 1/2 to 1 mL of saline solution then aspirate. A bloody "flashback” indicates that the marrow cavity has been entered. Marrow may not always be aspirated.
- Use 5 to 10 cc of NS to flush the needle and observe for extravasation and confirm placement. The fluid should flush easily.
- Fasten a T-connector with stopcock attached into the IO needle. Attach this to the IV tubing. (Figure 5) Attach the IV tubing as quickly as possible to prevent clotting. If for some reason the administration set cannot be connected, immediately replace the stylet until the tubing is ready. If the needle site cannot be confirmed, remove the needle and try another site. The proximal tibia and distal femur sites of both legs are acceptable to use.
- Blood samples taken from the intraosseous can be used to measure electrolytes, blood cultures, blood gases, type and cross, and hemoglobin. However, these lab tests are not the primary reason for this procedure; access is.2,7
After insertion of the intraosseous needle, secure the needle by using a piece of twill tape. Cut a piece of twill tape long enough to wrap around the leg and also to secure the knot. Form a loop at the middle of the twill tape. Pass the loop around the IO needle and pull the tape through it to form a Lark’s Head Hitch. Assure that the hitch will not slip by tying a single overhand knot around it. Pass one limb of the tape around the patient’s leg using a Magill forceps to pull it around with minimal movement then tie the two ends together. For an illustration of the Lark’s Head Hitch, see Vol II—AIR SKILLS 1, Aids to Intubation, Securing an ET Tube. If this is the only established IV site, guard it carefully until another site can be established.
Insertion of the Intraosseous Needle into the Distal Medial Tibia (Figure 6):
- Identify the puncture site one- to two-finger breadths proximal to the medial malleolus, sufficiently posterior to avoid the saphenous vein.
- Externally rotate the leg.
- Use only as last choice in young children.
- Prepare the skin with povidine.
- Hold the needle with stylet (trocar) in place at a right angle to the bone.
- Proceed with insertion, confirmation of proper placement, connection of the IV, and securing of the intraosseous needle as above.
Removal
If
the needle is removed, hold pressure on the site for 5 minutes and
cover with a sterile dressing. Do not attempt to reuse the site as this
will cause leakage of fluids into the surrounding tissue.
Substances That can be Infused Via Intraosseous Route
- Crystalloids, colloids, blood, and blood products,
- Medications such as calcium, glucose, atropine, sodium bicarbonate, epinephrine, diazepam, dopamine/dobutamine, and anesthetic agents.
Rate of Absorption of Medications and Fluids
The
rate of absorption of meds given by IO appears to equal the rate given
by peripheral IV. Medications given IO take 15 seconds or less to reach
the central circulation. Flushing the IO line with 20 cc of NS after
the medication is given facilitates the rate at which medications reach
the central circulation. (Be careful not to cause fluid overload.)
Complications of the IO
Although complications are seldom, they may include the
following:
- Osteomyelitis
- Periostitis
- Subcutaneous edema due to leakage
- Fat embolus
- Subcutaneous abscess
- Growth plate injury
- Leakage out of another hole in the bone
- Bone marrow damage
- Skin infection
Formation of small, indurated areas at the injection site is commonly observed. These are the result of fluid escaping from the marrow cavity around the needle during the injection and accumulating in the soft tissue. These should resolve by themselves and cause no problems.
Infusion Techniques
Flow
through the intraosseous infusion line will usually be slow. Using a
syringe with a three-way stopcock or a pressure bag can enhance the
rate of infusion. Inflate the pressure bag to 300 torr. Some infusion
pumps may alarm when attached to an intraosseous needle due to the
pressure settings of the pump. Use of a syringe and three-way stopcock
attached to the IV line is an effective method to administer fluid.
Attach a 30 or 60 cc syringe to the three-way stopcock. (Figure 7)
Close the stopcock to the patient, and open the valve from the IV bag to the syringe. Withdraw the plunger to fill the syringe with the desired amount of IV fluid from the IV bag. Close the flow to the IV bag and open the valve allowing fluid to flow from the syringe to the patient. Inject the desired amount of fluid or medication to the patient. Repeat as necessary.
Manual IOs are being replaced in many hospitals by other devices, such
as the EZ-IO.
EZ-IO
The
EZ-IO® Product System by Vidacare® consists of a small, battery-powered
device and 3 needles specifically designed to provide safe, controlled
vascular access via the IO route in patients of all ages. The EZ-IO
needle sets are 15 mm (3 to 39 kg), 25 mm (≥ 40 kg), and 45 mm
(excessive tissue). The ≥ 40 kg needle was designed with a
beveled
drill tip to penetrate the hard exterior of adult bones, while the 3 to
39 kg needle is shorter in length for accessing the softer bones of
pediatric patients. The excessive tissue needle was designed for
overweight/obese patients. Note that the size of the needle used has
more to do with body fat than weight.
The most common site for IO
insertion is the proximal tibia. Alternative sites are the distal
femur, distal tibia, and humerus. For the tibia, the anatomical
landmarks are the same as those used for pediatric IO access, that is,
just medial to the tibial tuberosity, on the flat portion of the
proximal tibia. The distal femur is the second choice in pediatric
patients. Landmarks in the distal femur are harder to locate because
overlying tissues are thicker.
To insert in the distal femur, slightly flex and externally rotate the hip, and flex the knee so that the quadriceps are relaxed. Insert the needle in the anterior midline, above the external epicondyles, 1-3 cm above the femoral plateau.
For the humerus, the anatomical landmark is the anterior humeral head. Consider local anesthesia and prophylactic antibiotic administration only if time permits. This needle can remain in place safely up to 24 hours.
Procedure for EZ-IO Insertion
- Locate anatomical site and prep the skin.
- Infiltrate site with local anesthetic down to level of the periosteum if needed.
- Load needle into the driver. It attaches by a magnet.
- Firmly stabilize the leg near (not under) the insertion site.
- Firmly press the needle against the site at a 90-degree angle and operate the driver. Use firm, gentle pressure.
- As the needle reaches the bone, stop and ensure that the 5 mm needle marking is visible. If it is, continue to operate the driver.
- Power the needle into the bone until the flange touches the skin or a sudden lack of resistance is felt.
- While supporting the needle set with one hand, pull straight back on the driver to detach it from the needle set.
- Grasping the hub firmly with one hand, rotate the stylet counter clockwise until loose, pull it from the hub, place it in the stylet cartridge, and place in biohazard container
- The manufacturer recommends not attempting to aspirate bone marrow as it may clog the needle and tubing.
- If the patient responds to pain (GCS ≥8), administer preservative-free Lidocaine, 0.5 mg/kg up to a maximum of 50 mg slowly (30 sec).
- If no signs of infiltration are found, attach the IV line and infuse fluids and medications as normal. (IV bag will need to be under pressure.)
- Secure needle and dress the site.
EZ-IO Removal
- Remove the attached EZ-connect extension set.
- Attach a sterile 5 or 10 mL syringe luer lock syringe. (The syringe acts as a handle.)
- Rotate the syringe clockwise.
- While continuing to rotate the syringe, begin gently pulling the catheter out, avoiding use of excessive force.
- Apply a small sterile dressing to the site.
(See www.vidacare.com.)
References
- McHugh MJ. IO infusions in children. Emergency. January 1990:21-23.
- Friery J et al. Start an IV in that bone. Emergency. November 1987:28-33.
- Stenzel JP. Intraosseous venous access: teaching a new dog old tricks. Ramsey Critical Care Bulletin. June 1989.
- Rosetti VA, Thompson BM, Miller J, Mateer JR, Aprahamian C. Intraosseous infusion: an alternative route of pediatric intravascular access. Ann Emerg Med. 1985;14(9)885-888.
- Brillman JC. Intraosseous infusion for emergency intravascular access. Top Emergency Med. 1988;10:75-80.
- Waisman M, Waisman, D. Bone marrow infusion in adults. J Trauma. 1997;42:288-293.
- Dubick MA, Holcomb JB. A review of intraosseous vascular access: current status and military application. Mil Med. 2000;165(7):552-559.
- Calkins MD, Fitzgerald G, Bentley TB, Burris D. Intraosseous infusion devices: a comparison for potential use in special operations. J Trauma. 2000;48:1068-1074.