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. Data are available upon reasonable request.