Mepivacaine dosing for spinal anesthesia in pediatric orthopedic surgery: a retrospective chart review

Background: Mepivacaine is an intermediate-acting local anesthetic used for spinal anesthesia in adults. Currently, there are no published dosing guidelines for spinal mepivacaine in patients under age 18.

Aims: The purpose of this study is to describe the clinically used doses of mepivacaine by weight and age for orthopedic surgery in pediatrics.

Methods: We performed a retrospective chart review of patients aged 0-18 who received mepivacaine for spinal anesthesia from 2016 to 2022. We performed a secondary analysis for patients aged 0-18 who received spinal anesthesia with bupivacaine or chloroprocaine.

Results: The data extraction yielded 3627 single-shot mepivacaine spinals. Patient age ranged from 5 to 18 years. Median dosage in milligrams/kilograms (mg/kg) of mepivacaine was calculated for each age group. Our analysis revealed that dosage in mg/kg decreased by patient age and began to plateau at age 15. Bupivacaine was the most common single-shot spinal agent in patients under age 10. After age 10, mepivacaine was more common. Chloroprocaine began to be used in patients older than 8 years.

Conclusions: We describe mepivacaine dosage as a function of age and weight in patients younger than 18 years. As age and weight increased, a lower dose of mepivacaine per kg was administered for spinal anesthesia.