The goal of this clinical trial is to test whether the stethoscope can be used as a method of assessing endotracheal cuff pressure as effectively as a manometer and also to compare it with the balloon palpation/audible leak method frequently used in clinical practice in adult patients undergoing general anesthesia.

The main questions it aims to answer are:

• Is the stethoscope as effective as a manometer in assessing endotracheal cuff pressure?
• Is there a difference between stethoscope and audible leak/balloon palpation methods in assessing endotracheal cuff pressure? Participants will be randomly divided into 2 groups.
• Group P: After intubation, endotracheal cuff pressure will be assessed by audible leak/balloon palpation.
• Group S: After intubation, endotracheal cuff pressure will be assessed with a stethoscope.
• Control will be carried out with a manometer and the pressure values obtained in the groups will be corrected.

Researchers will compare ''stethoscope'' and ''audible leak/balloon palpation'' groups to see if which method is effective like a manometer.

Although the use of a manometer is recommended in daily practice to evaluate endotracheal tube cuff pressure for intubated patients, the cuff is still inflated using balloon palpation or audible leakage methods in many centers. Manometers may not be available in most centers. An acceptable cuff pressure ranges from 20 to 30 cm H2O. While the risk of aspiration increases below 20 cm H2O, at values above 30 cm H2O the circulation of the tracheal mucosa begins to deteriorate and related complications like ulceration, stenosis, and even fistula may develop.

The authors hypothesize that the stethoscope is as effective as a manometer in assessing endotracheal tube cuff pressure where a manometer is not available.

After informed consent is obtained from patients who meet the inclusion criteria for the study, the patients will be intubated following anesthesia induction and the method by which the patients' endotracheal tube cuffs will be inflated will be determined in a randomized manner using the sealed envelope method. Then, the cuff pressures will be checked with a manometer by an expert who does not know the method by which the cuff is inflated, if necessary, it will be corrected and the data will be recorded with the code assigned to the method. Statistical evaluations will be made on the data obtained by an analyst who does not know the names of the methods and which method was applied to which patient.

The difference between our study and previous studies:

• Previous studies had small numbers of patients.
• The authors designed a randomized controlled study with triple masking.

Inclusion Criteria:

• Being between the ages of 18-65
• Planning the operation under general anesthesia
• Performing endotracheal intubation during general anesthesia
• Elective surgeries
• Volunteering to participate in the study

Exclusion Criteria:

• Having a history of difficult intubation before
• Difficulty during intubation (repeated intubation attempts, etc.)
• rapid sequence intubation requirement
• Planning to undergo head and neck surgery
• Those with tracheal stenosis
• Previous intervention to the neck area (radiotherapy, tracheotomy, etc.)
• Pregnancy
• Obesity
• Those with respiratory diseases (COPD, asthma, etc.)
• Emergency surgery
• American Society of Anaesthesiologists physical status>3
• Refusing to participate in the study

After the study is finished, data from the study will be shared when reasonable reasons are presented.

Only the person who intubates the patient and inflates the cuff using a method will know what the procedure is.