How to Control Propofol Infusion in Pediatric Patients Undergoing Gamma Knife Radiosurgery

Abstract

Introduction: Although Gamma Knife radiosurgery (GKS) is commonly performed under local anesthesia, general anesthesia is sometimes required. The authors previously reported a remote-controlled patient management system consisting of propofol-based general anesthesia with a target-controlled infusion (TCI) that we designed for pediatric GKS. However, a commercially available propofol TCI system has age and weight limitations (<16 years and <30 kg). We examined a manually controlled regimen of propofol appropriate for pediatric GKS.

Methods: A pharmacokinetic model of the TIVA Trainer© with Paedfusor’s parameter was used. A manually controlled infusion scheme to achieve a sufficient level of propofol for pediatric GKS was examined in five models ranging from 10 to 30 kg.

Results: Following a loading dose of 3.0 mg/kg, the combination of continuous infusion of 14, 12, 10, and 8 mg/kg/h resulted in a target concentration of 3.0–4.0 μg/ml, the required level for pediatric GKS.

Conclusion: Propofol titration is a key issue in GKS. Manual infusion is less accurate than TCI, but the combination of a small bolus and continuous infusion might be a substitute. Considering the characteristics of propofol pharmacokinetics in children, co-administration of opioids is recommended.