Validity of Ultrasonography in Predicting Difficult Laryngoscopy and Confirming Endotracheal Intubation in Obese Emergency Surgical Patients
Conditions: Preoperative Ultrasound Assessment of the Upper Airway Can Predict Difficult Laryngscopy in Obese at Emergency Operations
Sponsor: Minia University

 
 إداسة الذساساث العليا 
Title: 
Validity of ultrasonography in predicting difficult 
laryngoscopy and confirming endotracheal intubation 
in obese emergency surgical patients 
عٌواى الشسالت باللغت ال
عشبيه 
صالحي
ت الووجاث الصوتي
ت 
 في
التٌب
ؤ بصعوب
ت تٌظيش الحٌجش
ة كيذ أ وت التٌبيب 
 داخل
الشغاه
ي في هشضي ا
لطواس
ئ الجشاحي
ت 
ٌالزيي يعاًوى هي السو
ت 
 
خطة بحث مقذمة 
لكلية الطب 
جامعة المنيا 
ايفاء
ا جزئيا لشروط 
الحصول على درجة الماجستير 
يف التخذير والعناية المركزة 
 
 هي
الطبيبت :
 
 همت عامر محمذ 
 
Protocol of Thesis submitted 
To the Faculty of Medicine 
Minia University 
In partial fulfillment of the 
Requirement of  Master 
Degree 
In Anesthesia and Intensive 
care 
 
By : 
 
Hemmat Amer Mohamed  
 

      الوششفوى 
Supervisors
 
 
أ.
 د م. اهيوت شحاتت هحوذ 
استا
ر هساعذ التخذيش والعٌايت الوشكزة 
كليت الطب - جاهعت الوٌيا 
Dr. Omyma Shehata Mohamed 
Assistant professor of Anesthesia and Intensive care 
Faculty of Medicine Minia University 
 د. طاسق عبذ الوٌعن عبذ الظاهش
 هذسس التخذيش والعٌايت الوشكزة 
كليت الطب - جاهعت الوٌيا 
Dr. Tarek Abd El-Moneim Abd El-Zaher 
Lecturer in Anesthesia and Intensive Care 
Faculty of Medicine - Minia University 
 
 د. هحوذ احوذ اهيي 
 هذسس األشعت التشخيصيت 
كليت الطب - جاهعت الوٌيا 
Dr. Mohamed  Ahmed Amin  
Lecturer of Diagnostic radiology 
Faculty of Medicine - Minia University 
 
 
 
 

Introduction 
Proper airway management (AM) is an essential goal for anesthesia 
providers. Poor airway assessment and planning contributed to 
unfortunate 
airway 
outcomes. 
Airway 
management 
skills 
are 
indispensable for an emergency physician. Unrecognized airway 
accidents such as esophageal intubation tend to occur more in emergency 
settings (1) where it is reported as 6%-16%.(2)  
The inability to successfully intubate a pharmacologically 
paralyzed patient can be a disastrous situation. Although patients who are 
potentially difficult to intubate can often be predicted clinically, this 
method does not provide complete assurance, providing a requirement to 
consider other methods. (3) Also, confirmation of proper tracheal 
intubation could be performed primarily by direct laryngoscopy, 
auscultation of Gurgling sounds in the epigastric region, lung 
auscultation, observation of water vapor on endotracheal tube wall, using 
esophageal detector device, CXR and ETCO2 (end-tidal CO2 pressure) 
that each of the above-mentioned methods have its own limitations (4-8). 
Obesity is a well-known independent predictor of difficult 
intubation, but increased body mass index poorly predicts difficult 
laryngoscopy.  
A large neck circumference is among the suggested predictors of 
difficult intubation, especially in obese patients and it has been reported 
to predict difficult laryngoscopy. Neck circumference, though, does not 
indicate the amount of soft tissue at various topographic regions within 
the neck. Distribution of fat in different neck areas may provide better 
information than neck circumference. (9)   

Ultrasound (US) offers a number of attractive advantages 
compared with competitive imaging techniques or endoscopy for imaging 
critically ill patients. It is widely available, portable, repeatable, relatively 
inexpensive, pain-free, and safe. 
Although the earliest reports dealing with US applications in 
clinical medicine include the description of soft-tissue imaging of the 
pretracheal structures and anterior Ultrasound (US) evaluation of the 
airway is found to be an excellent tool in different medical settings 
including the operating room, intensive care unit and in the emergency 
department (ER). The utility of the US in the airway management is not 
limited to the upper airway assessment; it has been also used to evaluate 
the lower airway, lungs and pleura (10).  
 
 
 

Aim of the work 
The aim of the study is to determine whether preoperative 
ultrasound assessment of of the upper airway can predict difficult 
laryngscopy in emergency surgical obese patients , by analysis 
correlations between ultrasound measurements of anterior cervical soft in 
the upper airway, and the Cormack–Lehane grade. And evaluate its role 
in confirming the endotracheal placement 
The secondary objective was to determine whether clinical 
screening tests are independent predictors of difficult airway. 
Inclusion criteria: 
Adult obese patients (BMI>35) of both sex aged from 18 to 60 
years undergoing urgent surgeries under general anasthesia with tracheal 
intubation.     
Exclusion criteria: 
. Patients with removable upper dentures, upper airway pathology, 
cervical spine fractures, full stomach, maxillofacial trauma or unstable 
patients and pregnant women will be excluded from the study. 
 
 

Patients and Methods 
Patients: 
This prospective study will be conducted in Anesthesia and ICU 
department in Minia University Hospital after obtaining approval from 
our faculty ethical committee and obtaining written informed consent 
from the patient's or the relatives in each case.  
Methods 
Preoperative evaluation and ultrasonography: 
Preoperative evaluation and ultrasound examination will be 
performed by an  anesthesiologists  who will not be involved in 
laryngoscopy and intubation before the surgery, data was obtained in 
standard fashion. The patient's information, medical history, ) history of 
obstructive sleep apnoea (OSA) (diagnosed by polysomnography, or 
undiagnosed sleep apnoea suspected by the presence of snoring and 
cessation of breathing during sleep); Physical examination height, weight, 
body mass index (BMI), loose or protruding upper teeth, or partially 
missing upper incisors or canines;   
Will evaluate the following variables: 
1- Mallampati score 
2-  Neck mobility (flexion/extension degrees from midline),  
3- Upper lip bite test,  
4-  Temporomandibular joint mobility assessed by mouth-opening 
and forward movement of the jaw and the ability to protrude the 
lower teeth further than the upper teeth;  
5- . A flexible ruler will be used to measure airway parameters, mouth 
opening (cm), thyromental distance (cm), sternomental distance 

(cm), hyomental distance (cm) and neck circumference (cm) at the 
level of the thyroid cartilage. 
The thicknesses of the anterior neck soft tissues will be measured 
with a portable ultrasound machine). A 6 to 13 MHz high frequency 
curvilinear ultrasound transducer was used for ultrasound scanning. 
Patients will be explained about the ultrasonography procedure and 
positioned in supine with the head in a neutral position. Ultrasonography 
with the probe placed in the transverse axis, craniocaudal sagittal scan, 
submental region of the neck. The distances will be measured at five 
levels (hyoid bone, epiglottis, cricothyroid membrane, thyroid isthmus 
and suprasternal notch) with normal and extended neck position in the 
median axis.  
Intraoperative: 
After 5 min. preoxygenation, anesthesia will be induced with 
fentanyl (1-2 μ g/kg), propofol (2-4 mg/kg) and succinylcholine  
(1 mg/kg). with patient’s head in sniffing position on a standard operating 
room pillow at a height of 5 cm., an anesthesiologist who is unaware of 
the ultrasound results will perform laryngoscopy with a Macintosh 
No. 3 blade and insert an endotracheal tube of the proper size. 
Laryngoscopic view will be graded according to the method 
described by Cormack and Lehane  as grade 1 (full view of the glottis), 
grade 2 (glottis partly exposed, anterior commissure not seen), grade 3 
(only epiglottis seen), or grade 4 (epiglottis not seen). No external 
laryngeal pressure will be applied while reporting the laryngeal view. 
If intubation failed after three attempts, the study ended and 
alternative methods for airway placement will be pursued. 

To confirm endotracheal intubation, tracheal ultrasound during 
endotracheal intubation (ETI) will be performed. Ultrasound probe will 
be set on the outside of larynx and glottis during intubation and tube 
passage through trachea is checked. 
Statistical analysis; Our results will be statistically analyzed and 
expressed as tables and figures. 
 
 

References 
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Freiberger D, Liu PL (1985) : A clinical sign to predict difficult tracheal 
intubation: a prospective study. Can Anaesth Soc J 32(4):429–434] 
2. Brodsky JB, Lemmens HJ, Brock-Utne JG, Vierra M, Saidman LJ 
(2002) Morbid obesity and tracheal intubation. Anesth Analg 94(3):732– 
3. Bond A: Obesity and difficult intubation. Anaesth Intensive Care 
1993; 21:828–830 
4. Pouraghaei M, Moharamzadeh P, Soleimanpour H, Rahmani F, 
Safari S, et al. (2014) Comparison between the effects of alfentanil, 
fentanyl and sufentanil on hemodynamic indices during rapid sequence 
intubation in the emergency department. Anesth Pain Med 4: e14618.  
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RR, et al. (2011) Role of anesthesiology curriculum in improving bag-
mask ventilation and intubation success rates of emergency medicine 
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8. Mahmoodpoor A, Soleimanpour H, Nia KS, Panahi JR, Afhami M, 
et al. (2013) Sensitivity of palm print, modified mallampati score and 3-
3-2 rule in prediction of difficult intubation. Int J Prev Med 4: 1063-1069. 
9 Ezri T, Gewurtz G, Sessler DI, et al: Prediction of difficult 
laryngoscopy in obese patients by ultrasound quantification of anterior 
neck soft tissue. Anaesthesia 2003; 58:1111–1114. 

10. Kristensen MS, Teoh WH, Graumann O, Laursen CB (2014): 
Ultrasonography for clinical decision-making and intervention in airway 
management:from the mouth to the lungs and pleurae. Insights Imaging 
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