Description

After obtaining the approval of the ethics committee of KBC Zagreb and the Faculty of Dentistry of the University of Zagreb, the research will be conducted at KBC Zagreb.

Criteria for patient inclusion are:

• patients older than 18 years
• ASA status 1-3,
• Patients who have an indication for an intraoral surgical procedure longer than 30 minutes.
• patients who agreed to the research and signed the consent

Exclusion criteria are:

• ASA status higher than 3,
• the need for postoperative care in the ICU,
• surgery lasting more than 2 hours,
• known allergies to drugs used in the trial,
• refusal to participate Participants will be randomly divided according to a predetermined randomization table (32) into the TIVA group and the Volatile group. After identification of the participants in the operating room, participants will be fitted with a peripheral venous line, electrocardiogram monitoring, non-invasive blood pressure measurement, pulse oximeter, capnograph, temperature probe, and bispectral index (BIS) of the electroencephalogram and neuromuscular monitoring, kinemiography with train-of-four (TOF , M-NMT, Drägerwerk AG & Co. KGaA,) by recording the responses.

The initial anesthesiological induction procedure will not differ in both groups of patients. The drugs that will be used are sufentanil 0.3mcg/kg, propofol 2mg/kg, and cisatracurium 0.1mg/kg.

Participants will be intubated with an endotracheal tube and mechanically ventilated with a mixture of oxygen and air (inspiratory fraction of oxygen 40%) with a total flow of gas mixture of 3 L/min.

Anesthesia will be maintained in the volatile group with the inhaled anesthetic sevoflurane and single doses of cisatracurium. Cisatracurium will be repeated when the TOF ratio is greater than 5%, and the repeat dose will be 0.01 mg/kg. The depth of anesthesia will be controlled by BIS, maintaining values between 25 and 50. Recommended drug doses will be guided by TOF and BIS values.

In the TIVA group, anesthesia will be maintained with a continuous infusion of propofol (5-10 mg/kg/h) and single doses of cisatracurium. Cisatracurium will be repeated when the TOF ratio is greater than 5%, and the repeat dose will be 0.01 mg/kg. The depth of anesthesia will be controlled by BIS, maintaining values between 25 and 50. Recommended drug doses will be guided by TOF and BIS values.

At the end of the surgical intervention in both groups, the neuromuscular block will be antagonized with prostigmine (0.05 mg/kg) along with atropine (0.01 mg/kg) as soon as the patient begins to breathe spontaneously. Patients will then be extubated when the TOF index is greater than 90%

Muscle strength of all participants will be measured with a JAMAR hand dynamometer, and bite force with a gnathodynamometer (Bite force sensor, Monad electronics) in four time intervals:

1. Before introduction to anesthesia
2. After waking up from anesthesia in the operating room
3. 1 hour after waking up from anesthesia in the recovery room
4. After 24 hours from the operation

All patients will fill out the Quality of recovery-40 (Qor-40) questionnaire for assessing the quality of recovery after anesthesia and surgery in four time intervals:

1. Before introduction to anesthesia
2. 1 hour after waking up from anesthesia in the recovery room
3. After 24 hours from the operation
4. After 30 days from the operation Consent for the use of the QoR-40 questionnaire was obtained by the main researcher from the author, Professor P.S. Myles, and Dr. M. Miklić Bublić, who translated the questionnaire into Croatian.

Postoperative nausea and vomiting and postoperative shivering will also be recorded.

In the perioperative period, all participants will be placed in the department of otorhinolaryngology and head and neck surgery, where they will all receive the same postoperative care.

For a test power of 80% and the use of an independent t-test for the primary objective and x2 test for the secondary objective with a statistical significance of 0.05, it is necessary to include 42 patients, 21 subjects per group. The test for power calculation is G Power Version 3.1.9.6)(33). And the results will be processed with IBM SPSS statistics v27.