Local Anesthesia for Tibial Intraosseous (I/O) Access
Administer 2% lidocaine with epinephrine (40 mg, or 2 mL) through the I/O needle directly into the bone marrow space after successful I/O placement, followed by a slow flush with normal saline to minimize the severe pain associated with bone marrow aspiration and fluid infusion in conscious patients.
Key Clinical Context
The Association of Anaesthetists guidelines explicitly note that aspiration of bone marrow during I/O access is painful in awake patients, establishing the critical need for local anesthesia in conscious individuals 1. While the guidelines focus on I/O technique and complications, they do not provide specific anesthetic protocols for the procedure itself 1.
Recommended Anesthetic Technique
Intraosseous Lidocaine Administration
Inject 40 mg (2 mL) of 2% lidocaine with epinephrine directly through the I/O needle into the marrow space after confirming proper placement 2, 3.
The addition of epinephrine to lidocaine is safe and recommended, as it provides vasoconstriction that slows systemic absorption and prolongs the anesthetic effect 1, 2.
Wait 60-90 seconds after lidocaine administration before initiating fluid infusion to allow adequate anesthetic effect 4.
Follow the lidocaine injection with a slow saline flush (5-10 mL over 30-60 seconds) to distribute the anesthetic throughout the marrow space and reduce infusion pain 1.
Dosing Safety Parameters
The maximum safe dose of lidocaine with epinephrine is 7.0 mg/kg in adults 2, 3.
For children, the maximum dose is 3.0-4.5 mg/kg 2.
A 40 mg dose (2 mL of 2% lidocaine) is well below toxic thresholds for most patients and provides adequate intraosseous anesthesia 2, 3.
Optional Skin and Periosteal Anesthesia
Pre-Insertion Local Infiltration
Consider infiltrating 1-2 mL of buffered 1% lidocaine with epinephrine at the skin insertion site (2 cm distal to the tibial tuberosity, 1 cm medial to the tibial plateau) before I/O needle placement 1.
Buffering lidocaine with sodium bicarbonate significantly reduces injection pain and is strongly recommended for subcutaneous infiltration 1.
Use a slow infiltration rate to minimize discomfort during administration 1, 2.
Warming the lidocaine solution to body temperature (37-40°C) reduces infiltration pain based on high-quality evidence 1, 2, 3.
Technique Considerations
The skin/periosteal infiltration is less critical than intraosseous anesthesia because the primary source of pain is bone marrow distension and infusion, not needle insertion 1, 4.
If performing skin infiltration, use the smallest practical needle and aspirate before injection to avoid intravascular administration 2, 3.
Critical Pitfalls and Complications
Pain Management Failures
Failure to administer intraosseous lidocaine results in severe pain during fluid infusion in conscious patients, with studies reporting moderate to severe pain in 2-27% of cases without adequate anesthesia 4.
Intraosseous anesthesia without a vasoconstrictor has short duration (less than 30 minutes), while lidocaine with epinephrine provides 60+ minutes of anesthesia 4.
Cardiovascular Monitoring
46-100% of patients experience transient tachycardia when epinephrine-containing solutions are used for intraosseous anesthesia due to rapid systemic absorption from the marrow space 4.
This tachycardia is generally well-tolerated and self-limited, but continuous monitoring is warranted 4.
Anatomical Precision
The tibial insertion site is 2 cm distal to the tibial tuberosity and 1 cm medial to the tibial plateau 1.
In children, avoid the epiphyseal growth plate to prevent growth disturbances 1.
Studies show paramedics often misidentify the correct anatomical site by an average of 4.13 cm at the tibia, emphasizing the need for precise landmark identification 5.
Device Removal and Duration
Remove I/O devices as soon as suitable IV access is achieved, ideally within 24 hours of placement 1.
Complications include fracture, extravasation, osteomyelitis, infection, compartment syndrome, and pressure necrosis 1.
The distal femur may offer marginally higher success rates than the proximal tibia in pediatric patients, though this site is less commonly used 6.