Study on the Decision Support System of Difficult Airway Evaluation

Department of Anesthesiology, Peking University Third Hospital, Associate Chief Physician; M.D.

Based on the evaluation of preoperative physical indicators and radiologic indicators of cervical surgery, this study puts forward effective indicators for predicting difficult airway before operation, and establishes a comprehensive decision support system of difficult airway evaluation, so as to provide a theoretical basis for the early warning of difficult airway before cervical spondylosis surgery.

Study Overview

• Status: Recruiting
• Conditions: Difficult Airway
• Intervention / Treatment: Procedure: endotracheal intubation

Detailed Description

In the past, the evaluation of difficult airway mainly depended on physical indicators, but the internal structure of airway could not be found by appearance inspection. Therefore, unexpected emergency airway often appeared in clinical work, which seriously affected medical safety. In this study, the specific mechanism of difficult laryngoscopy in patients undergoing cervical spondylosis surgery is clarified by the combination of the physical indicators and radiologic indicators. On this basis, we will establish the preoperative airway evaluation system for cervical spondylosis surgery, optimize the standardized process of preoperative airway evaluation, and accurately screen out high-risk patients.

• Study Type: Observational
• Enrollment (Estimated): 1000

Contacts and Locations

• Study Contact: Name: Yongzheng Han, M.D.; Phone Number: +86 15201304460; Email: hanyongzheng@bjmu.edu.cn

Study Locations

• China
  • Beijing
    • Beijing, Beijing, China, 100191
      • Recruiting
      • Peking University Third Hospital
      • Contact: Yongzheng Han, M.D.; Phone Number: +86 15201304460; Email: hanyongzheng@bjmu.edu.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Probability Sample

Study Population

patients undergoing elective cervical spine surgery for cervical spondylosis (spinal cord and nerve root type

Description

Inclusion Criteria:

• patients of ASA I-III
• scheduled for elective surgery for cervical spondylosis under general anesthesia with tracheal intubation

Exclusion Criteria:

• patients with cervical spine instability
• oropharyngeal mass
• airway disease
• preoperative imaging data were incomplete
• refuse to sign informed consent

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
difficult laryngoscopy group; Cormack-Lehane (C-L) scale: class III-IV	Procedure: endotracheal intubation; all patients will receive laryngoscopy and endotracheal intubation
easy laryngoscopy group; Cormack-Lehane (C-L) scale: class I-II	Procedure: endotracheal intubation; all patients will receive laryngoscopy and endotracheal intubation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cormack-Lehane (CL) classification	describe laryngeal view during direct laryngoscopy	During induction

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
X1(X-ray indicators)	distance between the temporomandibular joint and tip of the upper incisors	During review the X-ray image
X2(X-ray indicators)	perpendicular distance from the hard palate to the tip of the upper incisors	During review the X-ray image
X3(X-ray indicators)	length of the mandibular body	During review the X-ray image
X4(X-ray indicators)	vertical distance from the highest point of the hyoid bone to the mandibular body	During review the X-ray image
X5(X-ray indicators)	distance from the antero-inferior border of the fourth cervical vertebra to the antero-superior border of the first cervical vertebra	During review the X-ray image
X6(X-ray indicators)	atlanto-occipital gapantero-superior border of the first cervical vertebra	During review the X-ray image
X7(X-ray indicators)	horizontal distance from the highest point of the hyoid bone to the border of the nearest cervical vertebra	During review the X-ray image
X8(X-ray indicators)	distance between the spinous processes of the first cervical vertebra and the second cervical vertebra	During review the X-ray image
A1 (X-ray indicators)	the angle between a line passing through the bottom of second cervical vertebra and a line passing through the bottom of sixth cervical vertebra in the neutral/ extension position	During review the X-ray image
Hp-h (CT/MRI indicators)	the distance from back end of the hard palate to the top of hyoid	During review the CT/MRI image
Ht (CT/MRI indicators)	the height of the tongue base, along Hp-h from the tongue to the top of hyoid	During review the CT/MRI image
Dt-p (CT/MRI indicators)	the distance from the back end of tongue to posterior pharyngeal wall	During review the CT/MRI image
Dt (CT/MRI indicators)	the distance from the back end of tongue to Hp-h	During review the CT/MRI image
S (CT/MRI indicators)	the central sectional area of the tongue base behind Hp-h	During review the CT/MRI image
W (CT/MRI indicators)	the maximal width of the tongue base	During review the CT/MRI image
V (CT/MRI indicators)	volume of the tongue base	During review the CT/MRI image
Rs (CT/MRI indicators)	Rs= S/( Hp-h* Dt-p); Rv =V/( Hp-h* Dt-p*W)	During review the CT/MRI image
MRI1 (MRI indicators)	distance between the base of the tongue and the posterior pharyngeal wall	During review the CT/MRI image
MRI2 (MRI indicators)	distance between the epiglottis and the posterior pharyngeal wall	During review the CT/MRI image
MRI3 (MRI indicators)	distance between the uvula and the posterior pharyngeal wall	During review the CT/MRI image
MRI4 (MRI indicators)	distance between the vocal cords and the posterior pharyngeal wall	During review the CT/MRI image
MRI5 (MRI indicators)	length of the epiglottis	During review the CT/MRI image

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
inter-incisor gap	physical indicator	measurement one day before operation]
thyromental distance	physical indicator	measurement one day before operation]
neck circumference,	physical indicator	measurement one day before operation]
modified Mallampati test,	physical indicator	measurement one day before operation]

Collaborators and Investigators

• Sponsor: Peking University Third Hospital
• Investigators: Study Chair: Yongzheng Han, M.D., Peking University Third Hospital

Publications and helpful links

General Publications

• Han YZ, Tian Y, Xu M, Ni C, Li M, Wang J, Guo XY. Neck circumference to inter-incisor gap ratio: a new predictor of difficult laryngoscopy in cervical spondylosis patients. BMC Anesthesiol. 2017 Apr 4;17(1):55. doi: 10.1186/s12871-017-0346-y.
• Han YZ, Tian Y, Zhang H, Zhao YQ, Xu M, Guo XY. Radiologic indicators for prediction of difficult laryngoscopy in patients with cervical spondylosis. Acta Anaesthesiol Scand. 2018 Apr;62(4):474-482. doi: 10.1111/aas.13078. Epub 2018 Jan 31.

Study record dates

Study Major Dates

• Study Start (Actual): March 21, 2022
• Primary Completion (Estimated): December 31, 2025
• Study Completion (Estimated): March 31, 2026

Study Registration Dates

• First Submitted: November 20, 2023
• First Submitted That Met QC Criteria: December 22, 2023
• First Posted (Actual): December 27, 2023

Study Record Updates

• Last Update Posted (Actual): December 27, 2023
• Last Update Submitted That Met QC Criteria: December 22, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: IRB00006761-M2022105

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: if necessary, access the data by contacting the project leader
• IPD Sharing Time Frame: after the project finished and manuscript published
• IPD Sharing Access Criteria: contact the project leader and data can only be used for scientific research
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No