Ultrasound Assessment of Airway Edema During Laparoscopic Cholecystectomy

Ultrasonographic Assessment of Airway Edema Induced by Intra-abdominal Pressure During Laparoscopic Cholecystectomy: A Prospective, Double-Blind, Randomized Study

This prospective, double-blind, randomized clinical trial aims to investigate the development of airway edema associated with intra-abdominal pressure during laparoscopic cholecystectomy. A total of 66 adult patients undergoing elective laparoscopic cholecystectomy under general anesthesia will be randomly assigned into two equal groups (33 patients per group) based on intra-abdominal pressure levels: low-pressure and standard-pressure pneumoperitoneum. Ultrasonographic measurements will be used to assess airway soft tissue thickness at predefined time points before and after the pneumoperitoneum. The primary objective is to determine whether increased intra-abdominal pressure contributes to postoperative airway edema, which may pose a risk during extubation.

Airway edema can lead to difficult extubation and perioperative complications. Pneumoperitoneum during laparoscopic surgery increases intra-abdominal pressure (IAP), which may contribute to airway soft tissue edema due to cephalad fluid shifts and venous congestion. This prospective, randomized, double-blind study aims to assess whether different levels of IAP have a measurable effect on airway soft tissue thickness.

Patients aged 18 to 65 years, classified as ASA I-II, and scheduled for elective laparoscopic cholecystectomy will be included in the study. Upon arrival in the operating room, standard monitoring will be applied, anesthesia will be induced using intravenous sedation, and endotracheal intubation will be performed.

In the preoperative period, airway ultrasonography will be used to measure tongue thickness, midsagittal tongue cross-sectional area, tongue width, lateral pharyngeal wall thickness, parapharyngeal area thickness, and submental area thickness.

Patients will be randomly assigned into two groups:

Group 1: Patients receiving 10 mmHg intra-abdominal pressure Group 2: Patients receiving 14 mmHg intra-abdominal pressure

T0: Before intubation

T1: After intubation

T2: 30 minutes after the initiation of pneumoperitoneum

T3: 5 minutes after extubation

T4: 1 hour after extubation

T5: 2 hours after extubation

Inclusion Criteria:

• Age between 18 and 65 years
• ASA physical status I-II
• Body mass index (BMI) < 30 kg/m²
• Mallampati score I-II
• Scheduled for elective laparoscopic cholecystectomy

Exclusion Criteria:

• History of difficult intubation
• Upper respiratory tract infection
• Obstructive sleep apnea or STOP-Bang score ≥3
• Severe cardiopulmonary disease
• Pregnancy
• Indication for emergency surgery