Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12617000482369
Ethics application status
Approved
Date submitted
7/01/2017
Date registered
3/04/2017
Date last updated
3/04/2017
Type of registration
Retrospectively registered

Titles & IDs
Public title
Ultrasound measurements of anterior soft tissue thickness to predict difficult laryngoscopy in women undergoing elective cesarean section under general anesthesia.
Scientific title
Ultrasound measurements of anterior soft tissue thickness to predict difficult laryngoscopy in women undergoing elective cesarean section under general anesthesia.
Secondary ID [1] 290786 0
nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
difficult laryngoscopy 301417 0
Condition category
Condition code
Anaesthesiology 301146 301146 0 0
Other anaesthesiology

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Prospective, observational study included 140 pregnant women (18-45 years old, ASA I-II) who underwent elective cesarean section under general anesthesia. A written informed consent was obtained from each patient. Patients with difficult airway anamnesis, history of neck surgery were not included in the study.
In addition, very urgent cases such as acute fetal distress and ablatio placenta were excluded from the study. Mallampati test, mouth opening, sternomental distance, thyromental distance, upper lip bite test, neck circumference were recorded one day before operation. The distance from the skin to the anterior aspect of the trachea was measured at five different levels: hyoid bone (zone 1), tirohyoid membrane (zone 2), vocal cords (zone 3), thyroid isthmus (zone 4) and suprasternal notch (zone 5). An anaesthesiologist who were unaware of the clinical screening variables and ultrasonography results performed laryngoscopy.
Intervention code [1] 296726 0
Early Detection / Screening
Comparator / control treatment
no control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 300554 0
Primary outcome: The determining ultrasound measurements of 5 different levels (Hyoid bone, Thyrohyoid membrane, Vocal cords, Thyroid isthmus, Suprasternal notch) of anterior neck soft tissue:
Timepoint [1] 300554 0
24 hours prior to general anesthesia
Secondary outcome [1] 330295 0
Secondary Outcome: clinical screening test for detecting of difficult laryngoscopy:
Mouth openning (cm),assessed using a caliper.
Timepoint [1] 330295 0
once at 24 hours prior to general anesthesia
Secondary outcome [2] 333134 0
Modified Mallampati Score assessed as a visiual parameter
Timepoint [2] 333134 0
once at 24 hours prior to general anesthesia
Secondary outcome [3] 333135 0
Thyromental distance (cm),assessed using a caliper.
Timepoint [3] 333135 0
once at 24 hours prior to general anesthesia
Secondary outcome [4] 333136 0
Sternomental distance (cm),assessed using a caliper.
Timepoint [4] 333136 0
once at 24 hours prior to general anesthesia
Secondary outcome [5] 333137 0
Cormack&Lehane Classification, assessed using Macintosh No:3 blade
Timepoint [5] 333137 0
at the moment of laryngoscopy
Secondary outcome [6] 333138 0
protruding upper teeth
Timepoint [6] 333138 0
once at 24 hours prior to general anesthesia
Secondary outcome [7] 333139 0
Wilson risk sum score
Timepoint [7] 333139 0
once at 24 hours prior to general anesthesia
Secondary outcome [8] 333140 0
Neck circumference measured at the thyroid cartilage,assessed using a caliper.
Timepoint [8] 333140 0
once at 24 hours prior to general anesthesia
Secondary outcome [9] 333141 0
Intubation Difficulty Scale (IDS, )assessed using Macintosh No:3 blade
Timepoint [9] 333141 0
15 mins after endotracheal intubation

Eligibility
Key inclusion criteria
18-45 years old
ASA (American Society of Anesthesiologists) II
elective cesarean section surgery
general anesthesia
Minimum age
18 Years
Maximum age
45 Years
Sex
Females
Can healthy volunteers participate?
No
Key exclusion criteria
difficult airway anamnesis
history of neck surgery

Study design
Purpose
Duration
Selection
Timing
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
7/04/2014
Date of last participant enrolment
Anticipated
Actual
8/04/2016
Date of last data collection
Anticipated
Actual
8/04/2016
Sample size
Target
140
Accrual to date
Final
140
Recruitment outside Australia
Country [1] 8515 0
Turkey
State/province [1] 8515 0
Bursa

Funding & Sponsors
Funding source category [1] 295205 0
Hospital
Name [1] 295205 0
Health Sciences University Bursa Yuksek Ihtisas Training and Education Hospital
Country [1] 295205 0
Turkey
Primary sponsor type
Individual
Name
Canan Yilmaz
Address
Health Sciences University Bursa Yuksek Ihtisas Training and Education Hospital Clinic of Anesthesiology And Reanimation Mimar Sinan Neighbohood/Emniyet Street/ 16310 Yildirim/Bursa
Country
Turkey
Secondary sponsor category [1] 294038 0
Individual
Name [1] 294038 0
Derya Karasu
Address [1] 294038 0
Health Sciences University Bursa Yuksek Ihtisas Training and Education Hospital Clinic of Anesthesiology And Reanimation Mimar Sinan Neighbohood/Emniyet Street/ 16310 Yildirim/Bursa
Country [1] 294038 0
Turkey

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 296556 0
Health Sciences University Bursa Yuksek Ihtisas Training and Education Hospital Clinical Research Ethics Committee
Ethics committee address [1] 296556 0
Health Sciences University Bursa Yuksek Ihtisas Training and Education Hospital Mimar Sinan Neighborhood /Emniyet Street/16310 / Yildirim /Bursa
Ethics committee country [1] 296556 0
Turkey
Date submitted for ethics approval [1] 296556 0
27/03/2014
Approval date [1] 296556 0
02/04/2014
Ethics approval number [1] 296556 0
2014/08/01

Summary
Brief summary
Obstetric patient airway management is becoming important, because of anatomical and physiological changes in the airway related to the pregnancy. The aim of our study was to compare the ultrasound (USG) measurements of 5 different levels of anterior neck soft tissue and other clinical screening tests for determination of difficult laryngoscopy in patients who underwent cesarean section operation with general anesthesia..
Materials and Methods:
Prospective, observational study included 140 pregnant women (18-45 years old, ASA I-II) who underwent elective cesarean section under general anesthesia. A written informed consent was obtained from each patient. The study protocol was approved by the local Ethics Committee. Patients with difficult airway anamnesis, history of neck surgery were not included in the study. In addition, very urgent cases such as acute fetal distress and ablatio placenta were excluded from the study. Mallampati test, mouth opening, sternomental distance, thyromental distance, upper lip bite test, neck circumference were recorded. The distance from the skin to the anterior aspect of the trachea was measured at five different levels: hyoid bone (zone 1), tirohyoidmembrane (zone 2), vocal cords (zone 3), thyroid isthmus (zone 4) and suprasternal notch (zone 5). An anaesthesiologist who were unaware of the clinical screening variables and USG results performed laryngoscopy. When second attempt for intubation was failed, to use of other difficult intubation equipments were planned.

Results: 120 patients were evaluated statistically. According to Cormack and Lehane’s scale, patients were divided into two groups: a grade 1 or 2 was accepted easy laryngoscopy, whereas a grade 3 or 4 was considered difficult laryngoscopy. 30 patients were classified as having difficult laryngoscopy (25 %). All of the patients were entubated succesfully. Amoung the other clinical screening tests for difficult laryngoscopy: limited mouth opening (<3cm), high Wilson's Risk Score (> 2), large neck circumference (> 40 cm), unable to bite the upper lip, and high mallampati score (III-IV) were found higher in the difficult laryngoscopy group (p<0.05). Also, BURP maneuver, useage of gum elastic bougie, high intubation difficulty score (IDS =5), three more intubation attempts, airway difficulty rate were significantly higher in the difficult laryngoscopy group (p<0.05).
Conclusion(s): We thought that USG measurement of anterior neck soft tissue has no influence on determination of difficult laryngoscopy in pregnant patients.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 71282 0
Dr Hilal Erdem Solak
Address 71282 0
Health Sciences University Bursa Yuksek Ihtisas Training and Education Hospital Clinic of Anesthesiology ve Reanimation Mimar Sinan Neighborhood/Emniyet Street/16310 Yildirim /Bursa
Country 71282 0
Turkey
Phone 71282 0
+905057163727
Fax 71282 0
Email 71282 0
[email protected]
Contact person for public queries
Name 71283 0
Dr Canan Yilmaz
Address 71283 0
Health Sciences University Bursa Yuksek Ihtisas Training and Education Hospital Clinic of Anesthesiology ve Reanimation Mimar Sinan Neighborhood/Emniyet Street/16310 Yildirim /Bursa
Country 71283 0
Turkey
Phone 71283 0
+905059045989
Fax 71283 0
Email 71283 0
[email protected]
Contact person for scientific queries
Name 71284 0
Dr Derya Karasu
Address 71284 0
Health Sciences University Bursa Yuksek Ihtisas Training and Education Hospital Clinic of Anesthesiology ve Reanimation Mimar Sinan Neighborhood/Emniyet Street/16310 Yildirim /Bursa
Country 71284 0
Turkey
Phone 71284 0
+905057281175
Fax 71284 0
Email 71284 0
[email protected]

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