Comparison of Airway Ultrasonography and Conventional Difficult Airway Parameters for Predicting Difficult Airway in Obese Patients: A Prospective Observational Study
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 发起方
- 入组人数
- 70
- 试验地点
- 1
- 主要终点
- Correlation of Ultrasonographic Airway Parameters (DSHB and HMDR) with Cormack-Lehane Laryngoscopy Grade
研究概览
简要总结
Obesity is associated with anatomical changes in the upper airway that increase the risk of difficult laryngoscopy and difficult mask ventilation during anesthesia. Conventional airway assessment parameters such as Mallampati score, neck circumference, and STOP-BANG scale are widely used but have limited predictive accuracy in obese patients. Airway ultrasonography has emerged as a promising non-invasive tool for difficult airway prediction; however, ultrasonographic criteria have not yet been standardized.
This prospective observational study aims to evaluate the utility of airway ultrasonography in predicting difficult airway in adult obese patients (BMI >30 kg/m²) scheduled for elective surgery under general anesthesia. Ultrasonographic measurements will include the distance from skin to hyoid bone (DSHB) at the level of the hyoid bone, the anterior neck soft tissue thickness at the thyrohyoid membrane level, and the hyomental distance ratio (HMDR). These parameters will be compared with conventional airway assessment tools and correlated with intraoperative Cormack-Lehane laryngoscopy grade and Han Scale mask ventilation score to determine their predictive value for difficult airway.
详细描述
Airway management is a critical component of clinical anesthesia. A difficult airway is defined as a situation in which a conventionally trained anesthesiologist experiences difficulty with mask ventilation, laryngoscopy, supraglottic airway ventilation, tracheal intubation, extubation, or invasive airway management. Unanticipated difficult laryngoscopy and difficult mask ventilation can lead to catastrophic outcomes. The incidence of difficult laryngoscopy and intubation is estimated at 1.5-13%, and approximately 28% of anesthesia-related deaths are attributable to failed mask ventilation or intubation.
Obesity (BMI ≥30 kg/m²) is associated with significant anatomical alterations in the upper airway and head and neck region. Accumulation of adipose tissue in the pharynx and hypopharynx narrows the airway lumen. A larger tongue is more difficult to displace into the submental space during laryngoscopy. Enlarged tonsils further reduce oropharyngeal space. Fat deposition in the neck, shoulders, and back complicates optimal patient positioning for laryngoscopy. Excessive soft tissue around the face and cheeks impairs effective mask seal and ventilation.
With advances in portable ultrasound technology, airway ultrasonography has become an increasingly utilized clinical tool for preoperative airway assessment. However, ultrasonographic criteria for predicting difficult airway have not yet been standardized.
Study Protocol:
Adult obese patients (BMI >30 kg/m², aged 18-65 years, ASA I-III) scheduled for elective surgery requiring orotracheal intubation under general anesthesia will be enrolled. Prior to the operating room, the following conventional airway parameters will be assessed: neck circumference, Mallampati score, and STOP-BANG scale. Airway ultrasonographic measurements will be performed preoperatively and will include:
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Age 18-65 years
- •BMI >30 kg/m2
- •ASA physical status I, II, or III
- •Scheduled for elective surgery requiring orotracheal intubation under general anesthesia
- •Written informed consent obtained
排除标准
- •Emergency surgery
- •History of previous head and neck surgery or radiotherapy
- •Known or anticipated difficult airway (history of difficult intubation)
- •Presence of cervical spine pathology or limited neck mobility
- •Presence of oropharyngeal or laryngeal pathology
- •Pregnancy
- •Patients with tracheostomy
- •Refusal to participate
研究组 & 干预措施
Obese Patients Undergoing General Anesthesia
Adult obese patients (BMI >30 kg/m², aged 18-65 years, ASA I-III) scheduled for elective surgery requiring orotracheal intubation under general anesthesia. Preoperative airway assessment will include conventional parameters (Mallampati score, neck circumference, STOP-BANG scale) and airway ultrasonographic measurements (distance from skin to hyoid bone [DSHB] and hyomental distance ratio [HMDR]). Standard anesthesia induction will be performed with propofol 2 mg/kg, fentanyl 2 mcg/kg, and rocuronium 0.6 mg/kg. Mask ventilation difficulty will be graded using the Han Scale and laryngoscopy difficulty using the Cormack-Lehane classification. Anesthesia will be maintained with sevoflurane and remifentanil infusion targeting BIS 40-60.
干预措施: Airway Ultrasonography (Diagnostic Test)
结局指标
主要结局
Correlation of Ultrasonographic Airway Parameters (DSHB and HMDR) with Cormack-Lehane Laryngoscopy Grade
时间窗: Perioperative/Periprocedural
Preoperative ultrasonographic measurements including the minimum distance from skin to hyoid bone (DSHB) at the hyoid bone level and the hyomental distance ratio (HMDR, calculated as hyomental distance in full extension divided by hyomental distance in neutral position) will be correlated with the intraoperative Cormack-Lehane laryngoscopy grade. Cormack-Lehane grades III and IV will be defined as difficult laryngoscopy. The diagnostic accuracy of DSHB and HMDR in predicting difficult laryngoscopy will be assessed using ROC curve analysis.
次要结局
- Predictive Value of Conventional Airway Parameters for Difficult Laryngoscopy(Perioperative/Periprocedural)
- Predictive Value of Ultrasonographic and Conventional Airway Parameters for Difficult Mask Ventilation(Perioperative/Periprocedural)
研究者
emin mert koyuturk
Anesthesiologist, Principal Investigator
Fatih Sultan Mehmet Training and Research Hospital