Trendelenburg Angle and Upper Airway Ultrasound Findings in Laparoscopic Hysterectomy

Evaluation of the Effect of Trendelenburg Position on Upper Airway Edema by Ultrasonography and Its Relationship With Postoperative Clinical Airway Findings in Patients Undergoing Laparoscopic Hysterectomy

This observational study was designed to evaluate whether the Trendelenburg position used during laparoscopic hysterectomy is associated with swelling of the upper airway.

Women scheduled for elective laparoscopic hysterectomy under general anesthesia were included. During surgery, the angle of the operating table in the Trendelenburg position was measured. The upper airway was assessed with bedside ultrasound by measuring the distance from the skin to the epiglottis and the thickness of the tongue at different time points before and during surgery.

The study did not assign participants to any treatment or intervention. All participants received standard surgical and anesthetic care. After surgery, participants were monitored for early airway-related findings such as noisy breathing after extubation, need for extra oxygen, low oxygen saturation, or need for reintubation.

Laparoscopic hysterectomy often requires carbon dioxide pneumoperitoneum and Trendelenburg positioning to improve surgical exposure. This position may shift fluid toward the head and neck region and may contribute to swelling of upper airway soft tissues.

This single-center prospective observational study included adult female participants scheduled for elective laparoscopic hysterectomy under general anesthesia. No study-related intervention was assigned. The Trendelenburg angle was determined by the surgical team according to routine clinical need and was recorded using a digital inclinometer.

Upper airway ultrasound measurements were performed at three perioperative time points: before anesthesia induction in the supine position, after Trendelenburg positioning, and at the end of surgery before return to the supine position. The measured ultrasound parameters were distance from skin to epiglottis and tongue thickness.

After extubation, participants were monitored in the post-anesthesia care unit and during the first 24 postoperative hours for clinical airway findings, including postextubation stridor, supplemental oxygen requirement, oxygen saturation below 94% on room air, and reintubation. The study aimed to assess the relationship between Trendelenburg angle, ultrasound-measured upper airway soft tissue changes, and early postoperative clinical airway findings.

Inclusion Criteria:

• Female patients aged 18 to 65 years
• Scheduled for elective laparoscopic hysterectomy
• Planned surgery under general anesthesia
• American Society of Anesthesiologists physical status I to III
• Body mass index 35 kg/m² or lower
• Provided written informed consent for study participation

Exclusion Criteria:

• Known history of difficult airway or expected difficult airway on preoperative evaluation
• Mallampati class III or IV
• Congenital or acquired upper airway pathology
• Neck mass or previous neck surgery
• Body mass index greater than 35 kg/m²
• Pregnancy
• Emergency surgery
• Known chronic respiratory disease, such as chronic obstructive pulmonary disease or advanced asthma
• Upper respiratory tract infection within the previous three weeks
• Inability to communicate in Turkish
• Lack of cooperation
• Conversion to open surgery
• Requirement for blood transfusion or additional fluid resuscitation beyond the standard protocol
• Significant hypotension requiring vasopressor support
• Persistent high peak airway pressures with ventilatory difficulty
• More than two intubation attempts
• Withdrawal from the study

Exclusion Criteria:

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