SPI Value Relevance in Clinical Practice

Signs of non-adequate anaesthesia are motor and/or autonomic nervous system arousals during surgery.

Inclusion criteria

• Ability to provide written informed consent

• Age 18-80 years of age
• Surgery that is expected to last at least 2 hours under general anesthesia with endotracheal tube

Exclusion criteria

• Any subject that meets the definition of vulnerable subject as defined in ISO 14155:2011o Per ISO 14155:2011, a vulnerable subject is defined as an individual whose willingness to volunteer in a clinical investigation could be unduly influenced by the expectation, whether justified or not, of benefits associated with participation or of retaliatory response from senior members of a hierarchy in case of refusal to participate

• Any subject with a cardiac pacemaker
• Any subject with atrial fibrillation at the time of obtaining the baseline values
• Any subject with more than 5 ventricular extra systoles/minute at the time of obtaining the baseline values
• Any subject who needs invasive blood pressure measurement
• Any subject who show hemodynamics that would have qualified for being considered as a sign of inadequate anesthesia already at baseline:

o Mean blood pressure below 60 mmHg or above 100 mmHg o HR below 45 /min or above 100/min

• Any subject with epidural anesthesia or analgesia during the surgery. Epidural catheter may be placed pre-operatively, and used in the PACU, but not during the surgery
• Any subject having surgery that requires prone position
• Any subject with very high body mass index (>35) because of incompatibility with the target controlled anesthesia models used

• Any subject with known allergies to the specific anesthetic agents/ analgesic drugs intended for use in their surgeries
• Any subject with laryngeal mask airway
• Any subject who requires neuromuscular blocking agent infusion
• Any subject who is going to have major surgery with a high risk of extensive blood loss
• Any subject with known chronic use of opioids