Density Spectral Array Patterns During Total Intravenous Anesthesia with Intravenous Lidocaine for Craniotomy: An Illustrative Two-Case Series

Purpose

Intravenous lidocaine is used as an adjuvant to total intravenous anesthesia (TIVA). To our knowledge, density spectral array (DSA) patterns during intravenous lidocaine administration in propofol–remifentanil TIVA for craniotomy have rarely been described. We present two illustrative cases for educational and hypothesis-generating purposes. Patients and Methods: Two adults underwent craniotomy for tumor resection (left cerebellopontine angle, Case 1; suprasellar, Case 2) with effect-site target-controlled infusion of propofol (Schnider model) and remifentanil (Minto model) and a bilateral scalp block. After a 1.5 mg/kg bolus, lidocaine was infused at 1.5 mg/kg/hour (Case 1) or 2 mg/kg/hour (Case 2) and stopped 30 minutes before the end of surgery. Frontal bispectral index (BIS) and DSA were recorded throughout and interpreted qualitatively at the bedside and offline.