ANI and SPI Guided Intraoperative Analgesia

ANI and SPI Guided Intraoperative Analgesia in Patients Undergoing Neurosurgical Procedures Under General Anaesthesia

There is accumulating evidence that inappropriate analgesia is asssociated with increasing risk of perioperative complications. The aim of the study is to compare intraoperative analgesia guided according to different methods of intraoperative analgesia monitoring, ANI and SPI respectively.

The Surgical Pleth Index (SPI) and ANI (Analgesia Nociception Index) has been developed for monitoring of adequacy of analgesia during surgery.

The investigators want to compare anesthesiologist guided intraoperative analgesia with intraoperative analgesia guieded by ANI or SPI.

The following hypotheses have been made:

1. Anesthesiologist guided analgesia will result in lower surgical stress
2. Anesthesiologist guided analgesia will result in more hemodynamic stability and faster recovery of the patient after anesthesia

Inclusion Criteria:

• Patients undergoing scheduled neurosurgical procedures under general anesthesia
• GCS 15
• ASA physical status I - III
• elective procedures with estimated duration 1 - 3 hours

Exclusion Criteria:

• Presence of non-sinus rhythm
• pacemaker
• planned postoperative ventilation
• procedures with planned awake intervals
• chronic pain with opioid medication
• opioid addiction
• epidural administration of local anaesthetic in combination with opioid
• corticosteroid use
• hormonal contraception
• chronic respiratory disease with known respiratory failure