Trendelenburg Angle and Upper Airway Ultrasound Findings in Laparoscopic Hysterectomy

Izmir City Hospital68 enrolled

Overview

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.

Study Type

OBSERVATIONAL

Enrollment

Interventions

Trendelenburg positioning during laparoscopic hysterectomyOTHER

Participants underwent elective laparoscopic hysterectomy under general anesthesia as part of standard clinical care. Trendelenburg positioning was applied according to routine surgical need and was not assigned by the study protocol. The Trendelenburg angle was measured and recorded during surgery. Upper airway ultrasound measurements were obtained before and during surgery, and participants were monitored for postoperative clinical airway findings during the first 24 hours.

Eligibility

Sex: FEMALEMin age: 18 YearsMax age: 65 Years

Medical Language ↔ Plain English

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: \-

Outcomes

Primary Outcomes

Change in distance from skin to epiglottis

Distance from skin to epiglottis was measured using point-of-care upper airway ultrasonography before anesthesia induction, after Trendelenburg positioning, and at the end of surgery before return to the supine position. The outcome was the change from baseline to the end of surgery, expressed in centimeters.

Time frame: From before anesthesia induction to the end of surgery before return to the supine position

Secondary Outcomes

Change in tongue thickness

Tongue thickness was measured using point-of-care upper airway ultrasonography before anesthesia induction, after Trendelenburg positioning, and at the end of surgery before return to the supine position. The outcome was the change in tongue thickness from baseline to the end of surgery, expressed in centimeters.