Bupivacaine Dosing for Cervical Spine Injections
For cervical spine injections, use 1.5 mL of 0.5% bupivacaine (7.5 mg total) injected bilaterally at the C6-C7 level for paraspinous intramuscular injections, or 5 mg/day for intrathecal catheter tips positioned in the cervical spine. 1, 2
Paraspinous Intramuscular Cervical Injections
The established dose is 1.5 mL of 0.5% bupivacaine (7.5 mg) injected bilaterally adjacent to the C6 or C7 spinous process, providing rapid onset (5-10 minutes) with complete headache relief in 65% and partial relief in 20% of patients. 1
This technique demonstrated an 85.4% overall therapeutic response rate in 417 patients without significant adverse effects. 1
The bilateral injection totals 3 mL (15 mg bupivacaine), which remains well below the maximum safe dose of 2.5 mg/kg for plain bupivacaine or 3 mg/kg with epinephrine. 3, 4
Intrathecal Catheter Placement in Cervical Spine
For intrathecal drug delivery systems with catheter tips in the cervical spine, initiate bupivacaine at 5 mg/day as a continuous infusion. 2
This cervical-specific dosing is lower than thoracic dosing (8-10 mg/day) due to the increased risk of respiratory complications and high sensory block with cervical catheter placement. 2
In oncologic patients, this 5 mg/day starting dose achieved 59% reduction in pain scores and 70% reduction in oral morphine equivalents, though 16.3% experienced bupivacaine-related side effects (numbness, weakness, urinary retention). 2
Maximum Safe Dosing Considerations
The absolute maximum safe dose for any peripheral nerve block or infiltration is 2.5 mg/kg (up to 175 mg total) for plain bupivacaine, or 3 mg/kg (up to 225 mg total) when combined with epinephrine 1:200,000. 4, 3
For peripheral nerve blocks in the cervical region, the FDA label specifies 5-35 mL of 0.5% bupivacaine (25-175 mg) without epinephrine, or 5-45 mL (25-225 mg) with epinephrine. 4
Calculate doses based on actual body weight in normal-weight patients and ideal body weight in obese patients. 3
Critical Safety Considerations
Always aspirate before and during injection to avoid intravascular injection, which can cause systemic toxicity including cardiovascular collapse and seizures. 4
Cervical injections carry higher risk than lumbar procedures due to proximity to the brainstem and potential for rapid cephalad spread if inadvertently placed intrathecally. 2
For continuous catheter techniques, administer test doses before initial and all supplemental doses, as catheters can migrate into blood vessels or through the dura. 4
Have lipid emulsion (20% Intralipid) immediately available for treatment of local anesthetic systemic toxicity. 4