Patient State Index (PSI)

The Patient State Index (PSI) is a numerical value used by anesthesiologists to gauge the depth of anesthesia a patient is under during surgery. It is derived from brain wave activity measurements, helping clinicians ensure the patient is neither too awake nor too deeply sedated. A PSI score typically ranges from 0 (no brain activity, deep anesthesia) to 100 (fully awake). Maintaining the appropriate PSI helps minimize risks like awareness during surgery or excessive sedation, promoting safety and optimal anesthesia management throughout the procedure.