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.

Methylene Blue for Vasoplegia When on Cardiopulmonary Bypass During Double-Lung Transplantation.

Vasoplegia syndrome, characterized by hypotension refractory to fluid resuscitation or high-dose vasopressors, low systemic vascular resistance, and normal-to-increased cardiac index, is associated with increased morbidity and mortality after cardiothoracic surgery. Methylene blue inhibits inducible nitric oxide synthase and guanylyl cyclase, and has been used to treat vasoplegia during cardiopulmonary bypass. However, because methylene blue is associated with increased pulmonary vascular resistance, its use in patients undergoing lung transplantion has been limited. Herein, we report the use of methylene blue to treat refractory vasoplegia during cardiopulmonary bypass in a patient undergoing double-lung transplantation.