Predicting personalised remifentanil effect site concentration for surgical incision using the nociception level index: A prospective calibration and validation study

BACKGROUND Inadequate antinociception can cause haemodynamic instability. The nociception level (NOL) index measures response to noxious stimuli, but its capacity to predict optimal antinociception is unknown. OBJECTIVE To determine if NOL index change to a tetanic stimulus in cardiac and noncardiac surgery patients could predict the required remifentanil concentration for haemodynamic stability at skin incision. DESIGN A prospective two-phase cohort study. SETTING University hospital. PATIENTS Patients undergoing remifentanil-propofol target controlled infusion (TCI) anaesthesia. INTERVENTIONS During the calibration phase, investigators evaluated the tetanic stimulus induced NOL index change under standardised TCI remifentanil-propofol anaesthesia during a no-touch period [bispectral index (BIS) between 40 and 60, NOL index under 15]. If the NOL index change was 20 or greater following tetanic stimulation, investigators repeated the tetanus at higher remifentanil concentrations until the response was blunted. Surgeons incised the skin at this remifentanil concentration. The investigators derived a prediction model and in the validation phase calculated, using the NOL response to a single tetanus, the required incision remifentanil concentration for the start of surgery. MAIN OUTCOME Haemodynamic stability at incision [i.e. maximum heart rate (HR)
Source: European Journal of Anaesthesiology - Category: Anesthesiology Tags: Anaesthesia Source Type: research