Failed or Difficult Intubation
Conditions
Keywords
Difficult airway management, anesthesia, difficult intubation
Brief summary
The purpose of this study is to identify differences in craniofacial morphology and tongue size between patients who have a history of difficult airway management and a control group of patients who had an uneventful airway management during induction of general anesthesia. In this study the investigators want to validate the hypothesis that there are craniofacial phenotypic differences between patients who have a history of difficult airway management and a control group of patients who have had an uneventful airway management during the induction of general anesthesia.
Detailed description
Difficult airway management is one of the most challenging tasks for anesthesiologists. Recent data from the American Society of Anesthesiologists (ASA) Management Closed Claims Project \[1\] show that the percentage of claims resulting from adverse respiratory events, though on the decline (42% in the 1980s to 32% in the 1990s), continue to constitute a large source of morbidity and mortality in anesthetized patients. In 2005, a closed claims analysis of trends in anesthesia-related death and brain damage between 1975 and 2000 showed that out of all respiratory events (n=503) responsible for death and brain damage, difficult endotracheal intubation (n=115), inadequate oxygenation (n=111) and inadvertent esophageal intubation (n=66) were the top three causes \[2\].
Interventions
PROCEDURE3D Laser Scanning of the Head
Five scans will be collected from different angles, each scan taking approximately 3 seconds. Each scan will consist of a thin beam of light flashing of your head.
PROCEDUREMeasurements and Digital Photo's of the head, neck and Mouth
Prior to the photographs, certain bone and soft tissue areas such as angle of the jaw, neck and chin will be gently touched and marked with self-adhesive paper stickers. Using the self-adhesive paper stickers and a measuring tape, we obtain measurements of your head and neck. You will be also asked to open your mouth and a digital photograph of the back of the mouth will be taken, as well as, pictures of the front and side of the head and neck.
PROCEDUREUltrasound Exam of the Tongue
The ultrasound study of the tongue will be performed after the series of laser scans. You will be examined in the sitting position. A small,handheld, curved ultrasound instrument will be placed under the chin to take images of the tongue. This exam should take less than a minute
Sponsors
University of Rochester
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* patients that had undergone or will undergo a surgery under general anesthesia .
Exclusion criteria
* known history of syndromal craniofacial abnormalities (e.g. Down syndrome) * previous craniofacial surgery * excessive facial hair which significantly obscure facial landmarks * cervical spine fractures * tracheostomy tube * patients who are unable to give consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mean Hyomental Distance Ratio | end of study approximately one year | A curved low-frequency transducer and a Flex focul 400 ultrasound system were used to visualize the tongue and shadows of the hyoid bone and mandible. Midsagittal and coronal/transverse scans from the ultrasound were analyzed using ImageJ. The hyomental distances in the neutral and heal-extended positions were measured from the upper border of the hyoid bone to the lower border of the mentum. The ratio is defined as the ratio of the hyomental distance at the extreme of head extension to that in the neutral position. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Mean Tongue Volume | end of study approximately one year | The midsagittal scans were used to measure the cross-sectional area of the tongue. Transverse scans obtained in the midsection of the tongue (at the glossal end of the genioglossus muscle) provided a measure of the tongue width, which was measured between the most distant points on its upper surface. The tongue volume was derived from the multiplication of the midsagittal cross-sectional area by the tongue width. |
Countries
United States
Participant flow
Recruitment details
Recruitment period for this study is from 11-3-2010 to 10-1-2012 done in a medical clinic setting.
Pre-assignment details
Enrollment goal for this study was met so the study was closed.
Participants by arm
| Arm | Count |
|---|---|
| Difficult Intubation Patients Obese and morbidly obese patients with a large neck circumference. This arm was patients who were difficult to intubate during previous anesthetics provided by the staff anesthesiologists.
3D Laser Scanning of the Head, measurements and digital photos of the neck and ultrasound of the tongue were performed. | 12 |
| Control Obese and morbidly obese patients with a large neck circumference. The control group will consist of patients with easy laryngoscopy and intubation, recruited prospectively.
3D Laser Scanning of the Head, measurements and digital photos of the neck and ultrasound of the tongue were performed. | 16 |
| Total | 28 |
Baseline characteristics
| Characteristic | Difficult Intubation Patients | Control | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 12 Participants | 16 Participants | 28 Participants |
| Region of Enrollment United States | 12 participants | 16 participants | 28 participants |
| Sex: Female, Male Female | 3 Participants | 6 Participants | 9 Participants |
| Sex: Female, Male Male | 9 Participants | 10 Participants | 19 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 12 | 0 / 16 |
| serious Total, serious adverse events | 0 / 12 | 0 / 16 |
Outcome results
Primary
Mean Hyomental Distance Ratio
A curved low-frequency transducer and a Flex focul 400 ultrasound system were used to visualize the tongue and shadows of the hyoid bone and mandible. Midsagittal and coronal/transverse scans from the ultrasound were analyzed using ImageJ. The hyomental distances in the neutral and heal-extended positions were measured from the upper border of the hyoid bone to the lower border of the mentum. The ratio is defined as the ratio of the hyomental distance at the extreme of head extension to that in the neutral position.
Time frame: end of study approximately one year
Population: only 6 patients in each group were analyzed because the remaining patients were not eligible for analysis based on a review of their electronic medical chart
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Difficult Intubation Patients | Mean Hyomental Distance Ratio | 1.14 ratio | Standard Deviation 0.02 |
| Control | Mean Hyomental Distance Ratio | 1.02 ratio | Standard Deviation 0.01 |
Secondary
Mean Tongue Volume
The midsagittal scans were used to measure the cross-sectional area of the tongue. Transverse scans obtained in the midsection of the tongue (at the glossal end of the genioglossus muscle) provided a measure of the tongue width, which was measured between the most distant points on its upper surface. The tongue volume was derived from the multiplication of the midsagittal cross-sectional area by the tongue width.
Time frame: end of study approximately one year
Population: only 6 patients in each group were analyzed because the remaining patients were not eligible for analysis based on a review of their electronic medical chart
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Difficult Intubation Patients | Mean Tongue Volume | 137 cubic centimeters | Standard Deviation 29 |
| Control | Mean Tongue Volume | 168 cubic centimeters | Standard Deviation 34 |