Bupivacaine Spinal Dose for an 11-Year-Old, 140 cm Tall Patient
For an 11-year-old patient who is 140 cm tall, administer 0.5 mg/kg of bupivacaine for spinal anesthesia, which translates to approximately 15-20 mg total dose depending on the child's weight (typically 30-40 kg at this age and height). 1
Evidence-Based Dosing Algorithm
Age-Appropriate Dosing Strategy
The ESRA/ASRA Joint Committee recommends 0.5 mg/kg of bupivacaine for children older than 1 year of age for spinal anesthesia. 1 This is in contrast to the 1 mg/kg dose used in newborns and infants under 1 year.
For an estimated weight of 30-40 kg (typical for 140 cm height at age 11), this yields a total dose range of 15-20 mg of bupivacaine. 1
Maximum Safe Dose Considerations
The maximum safe dose of bupivacaine without epinephrine for peripheral nerve blocks is 2.5 mg/kg in pediatric patients. 2 However, spinal dosing follows different principles based on neuraxial spread rather than systemic toxicity limits.
The recommended 0.5 mg/kg dose for spinal anesthesia in children over 1 year remains well below systemic toxicity thresholds. 1
Height and Vertebral Column Considerations
While patient height is traditionally considered important for spinal dosing, vertebral column length (C7 to sacral hiatus) correlates more strongly with anesthetic spread than total body height. 3 However, in pediatric practice, the weight-based approach (0.5 mg/kg) has proven reliable and safe. 1
The height-based dosing algorithms described in adult literature are not well-validated in pediatric populations, making the weight-based approach more appropriate. 4, 3
Concentration and Volume Selection
Use bupivacaine 0.5% (5 mg/mL) concentration, which is standard for spinal anesthesia. 2 This allows for precise dosing in smaller volumes.
For a 15-20 mg dose, this translates to 3-4 mL of 0.5% bupivacaine. 2
Hyperbaric bupivacaine 0.5% is preferred for predictable spread and reliable surgical anesthesia. 1
Critical Safety Measures
Pre-Administration Calculations
Always calculate the maximum allowable dose in milligrams before starting the procedure to prevent dosing errors. 2
Verify the patient's actual weight rather than estimating, as this directly determines the appropriate dose. 1
Monitoring Requirements
Document vital signs at least every 5 minutes initially, then every 10-15 minutes once stable. 2
Monitor for signs of local anesthetic systemic toxicity, including CNS symptoms (circumoral numbness, metallic taste, seizures) and cardiovascular depression. 2
Toxicity Preparedness
Have 20% lipid emulsion immediately available (1.5 mL/kg bolus dose ready) for treatment of potential local anesthetic systemic toxicity. 2
Ensure benzodiazepines are available for seizure management if toxicity occurs. 2
Common Pitfalls to Avoid
Do not use the 1 mg/kg dose intended for infants under 1 year - this would result in excessive dosing and prolonged motor block in an 11-year-old. 1
Avoid using adult fixed-dose protocols (typically 10-15 mg regardless of weight) as these may be inappropriate for pediatric patients. 1
Do not reduce doses by 30% as recommended for infants under 6 months - this reduction does not apply to an 11-year-old patient. 2
Ensure proper concentration calculation: 0.5% bupivacaine = 5 mg/mL, not 0.5 mg/mL. 2