Nociception Assessment During Rapid Sequence Induction: A Prospective Observational Study of Practices and Complications - The NARSI Study

Background: RSI is a standard technique in anesthesia, primarily used to minimize the risk of aspiration. European guidelines leave the choice of hypnotic and neuromuscular blocking agent to the practitioner; the role of analgesics is not addressed. RSI induces sympathetic reactions linked to intense painful stimulation. Several monitors enable nociception assessment during general anesthesia, including in paralyzed patients (ANI, NOL, SPI). To date, no study has explored pain using the Analgesia Nociception Index during RSI.

Hypothesis: Rapid sequence induction induces sympathetic reactions associated with intense painful stimulation, which can be quantified using ANI.

Primary objective: To describe the impact on pain monitored by ANI of rapid sequence induction in anesthesia.

Secondary objectives: (1) Describe early complications (desaturation, hypotension, regurgitation); (2) Explore factors associated with pain; (3) Explore factors associated with complications.

Methods: Prospective monocentric observational cohort study, in routine care, with no additional examinations beyond standard management. Patients are monitored according to Société Française d'Anesthésie et de Réanimation (SFAR) guidelines, with additional non-invasive cutaneous electrodes placed on the right pectoral area for ANI monitoring. Induction begins after preoxygenation of at least 3 minutes. Induction drugs are at the discretion of the anesthesiologist. A timer is started at injection of the first induction drug (T0). Hemodynamic and ANI parameters are recorded during the first 5 minutes.