The Effect of Supraglottic Airway Insertion on the Accuracy of Cricothyroid Membrane Identification in Females

Airway Obstruction Clinical Trial

Official title:

The Effect of Supraglottic Airway Insertion on the Accuracy of Cricothyroid Membrane Identification in Females- a Prospective Observational Study.

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03105037
• Other study ID #: REC-2017-001
• Status: Completed
• Start date: January 31, 2017
• Est. completion date: March 31, 2017

Study information

• Verified date: September 2018
• Source: The Rotunda Hospital
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

Prospective, observational, study that will examine if a sited supraglottic airway (the igel) will increase the accuracy of identifying the cricothyroid membrane in female patients.

Consented patients that meet inclusion criteria are assessed by clinicians under general anaesthesia with and without a supraglottic airway in situ. The accuracy of CTM identification by palpation will be evaluated using ultrasound.

Description:

Palpation of the airway structures results in misidentification of the cricothyroid membrane (CTM) in a high proportion of women. Female front of neck anatomy is less distinct compared to males with reduced angulation of the laryngeal cartilages making it harder to distinguish the relevant landmarks. In obese patients, overlying subcutaneous tissue compounds this problem and several studies have demonstrated poor success identifying the CTM by palpation in this population. Supraglottic airway device (SAD) insertion precedes emergency front of neck access attempts in the stepwise progression from failed intubation to cricothyroidotomy. The nature and clinical implication of SAD insertion on cricothyroidotomy remain unstudied.

Sixty four patients will undergo front of neck airway assessment by volunteer clinicians with and without a SAD in situ (control and SAD assessments, within-subjects design). The patients are fasting women presenting for routine gynaecological surgery. Eight anaesthetists, at different levels of training, will perform eight individual CTM assessments with and without the SAD in situ.

Ultrasound images will be captured in the sagittal plane immediately before and after supraglottic airway insertion. Images are then downloaded, anonymised and randomised for blinded digital analysis.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 64
• Est. completion date: March 31, 2017
• Est. primary completion date: March 31, 2017
• Gender: Female
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Women attending for routine surgery

Exclusion Criteria:

• unable to give informed consent

• abnormal neck anatomy

• history of gastroesophageal reflux

• history of neck surgery or radiotherapy

• contraindication to supraglottic airway device insertion

Related Conditions & MeSH terms

• Airway Obstruction

Locations

Country	Name	City	State
Ireland	The Rotunda Hospital	Dublin

Sponsors (1)

Lead Sponsor	Collaborator
The Rotunda Hospital

Country where clinical trial is conducted

Ireland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	accurate identification of the cricothyroid membrane	accuracy of cricothyroid membrane identification, measured as either successful identification or unsuccessful (binary outcome). A successful identification is within 5mm of the midline and within the upper and lower borders of the cricothyroid membrane as measured using ultrasound.	At clinician assessment, on the day of patient recruitment.
Secondary	Accurate identification of the midline of the neck	Accurate identification of the midline of the neck, binary outcome. A successful identification is within 5mm of the midline of the cricothyroid membrane as measured using ultrasound.	At clinician assessment, on the day of patient recruitment.
Secondary	Difficulty of cricothyroid membrane assessment	Difficulty of assessing the cricothyroid membrane as graded subjectively by the clinician using a visual analogue scale (VAS) where '0' is the easiest possible assessment of the location of the cricothyroid membrane and '10' is the most difficult possible assessment of the location of the cricothyroid membrane.	At clinician assessment, on the day of patient recruitment.
Secondary	Time taken to attempt localisation of the cricothyroid membrane	The time taken in seconds to attempt localisation of the cricothyroid membrane	At clinician assessment, on the day of patient recruitment.
Secondary	Distance from clinician assessment to actual cricothyroid membrane location	The distance measured from the clinicians estimate of where the cricothyroid membrane is to where the actual location of the CTM is using ultrasound and measured in millimetres	On blinded, retrospective ultrasound analysis of images captured at the time of clinician assessment of the cricothyroid membrane. Blinded retrospective ultrasound assessment is to take place within 3 months of patient recruitment
Secondary	The distance from the skin to the first tracheal ring	The distance from the skin to the superficial surface of the first tracheal ring measured in millimetres using digital analysis of ultrasound images	On blinded, retrospective ultrasound analysis of images captured at the time of clinician assessment of the cricothyroid membrane. Blinded retrospective ultrasound assessment is to take place within 3 months of patient recruitment
Secondary	The distance from the skin to the cricoid cartilage	The distance from the skin to the superficial surface of the first tracheal ring measured in millimetres using digital analysis of ultrasound images	On blinded, retrospective ultrasound analysis of images captured at the time of clinician assessment of the cricothyroid membrane. Blinded retrospective ultrasound assessment is to take place within 3 months of patient recruitment
Secondary	The angle between the surface tissue interface of the cricothyroid membrane and the trachea	The angle between the surface tissue interface of the cricothyroid membrane and the trachea measured in degrees using digital analysis of ultrasound images	On blinded, retrospective ultrasound analysis of images captured at the time of clinician assessment of the cricothyroid membrane. Blinded retrospective ultrasound assessment is to take place within 3 months of patient recruitment