Effects of Audiovisual Distraction Versus Standard Sedation on Desaturation and Airway Intervention in OSA-patients Undergoing Total Knee Arthroplasty Under Neuraxial Anesthesia

Before consent patients will be thoroughly informed about possible risks or benefits and about their possibilities to end the study at any time point or to ask for additional sedation if they feel uncomfortable or anxious. After they consent, they will be randomly assigned to either receive standard sedation (Group 1) or audiovisual distraction (Group 2). Each group will consist of 30 patients. The randomization schedule will be created by a member of the Healthcare Research Institute using SAS software, who is not otherwise involved in the trial.

1. Standard of care sedation with an initial dose of midazolam in preparation for the administration of the neuraxial anesthesia; propofol infusion titrated to effect.
2. Audiovisual distraction during surgery and in the recovery room using video goggles and headphones; patients can choose a movie from a preexisting library; with an initial dose of midazolam in preparation for the administration of the neuraxial anesthesia, additional sedation with midazolam in 1 mg increments if requested by the patient or deemed necessary by the anesthesia provider.

The intraoperative anesthesia regimen will be standardized:

• All patients will be monitored according to the American Society of Anesthesiologists standard, receive either a radial arterial line or non-invasive blood pressure measurement according to the preferences of the anesthesia provider and O2 via nasal cannula or face mask in the operation room and the recovery room.

• ondansetron,decadron and ketorolac may be administered as per clinical judgment of the attending anesthesiologist.

• Patients in both groups will receive neuraxial anesthesia. The attending anesthesiologist is free to add an ultrasound guided peripheral nerve block:

• Neuraxial anesthesia (combined spinal-epidural, epidural or spinal) as preferred by the attending anesthesiologist. Decadron may be used as in addition to the local anesthetic if the anesthesia provider wishes to do so.

• If a peripheral nerve block is performed the appropriate amount of bupivacaine will be administered under ultrasound-guidance as a single shot.

• In case an epidural catheter was placed patients will receive a patient controlled epidural analgesia immediately after arrival at the recovery room for postoperative pain management.

• Opioids and other medications with sedative or respiratory depressant side effects that are not specifically mentioned above should be omitted (if possible without harm for the patient) Patients in the audiovisual distraction group will choose a movie, start watching it in the holding area and continue watching it in the operation room as well as the first 30 min in the recovery room. Audiovisual equipment will be removed for transfers or at patient request.