Lecture Title: Lecture Title: Airway Evaluation and Management

Lecturer name: Dr. Massoun Taha JasserLecturer name: Dr. Massoun Taha Jasser

Lecture Date: 17 /10 / 2014Lecture Date: 17 /10 / 2014

Lecture Objectives..Lecture Objectives..

Students at the end of the lecture will be able to:

1. Learn about basic airway anatomy2. Conduct a preoperative airway assessment3. Identify a potentially difficult airway4. Understand the issues around aspiration and its prevention5. Learn about the management of airway obstruction6. Become familiar with airway equipment7. Practice airway management skills including bag and mask ventilation,

laryngeal mask insertion, endotracheal intubation8. Learn about controlled ventilation and become familiar with ventilatory

parameters9. Appreciate the different ways of monitoring oxygenation and ventilation

Indications of intubation

• Resuscitation (CPR)• Prevention of lung soiling• Positive pressure ventilation (GA)• Pulmonary toilet• Patent airway (coma or near coma)• Respiratory failure(CO2 retention )

Requirement of successful intbatin

• 1-Normal roomy mandible

• 2-Normal T-M, A-O , and C-spine

Requirements of successful intubation

3-Alignment of 3 axes orAssuming sniffing position

-Any anomaly in these 3 jointsA-O, T-M or C-spine can resultIn difficult intubation

Airway Evaluation Take very seriously history

of prior difficulty Head and neck movement

(extension)◦ Alignment of oral, pharyngeal,

laryngeal axes◦ Cervical spine arthritis or

trauma, burn, radiation, tumor, infection, scleroderma, short and thick neck

Airway Evaluation

• Jaw Movement– Both inter-incisor gap and

anterior subluxation– <3.5cm inter-incisor gap

concerning– Inability to sublux lower

incisors beyond upper incisors

• Receding mandible• Protruding Maxillary

Incisors (buck teeth)

Thyromental Distance

• Have the patient extend their head fully. Measure from the mentum (chin) to the thyroid notch.

• Over 7 cm (around 3 fingerbreadths) is associated with easier intubation.

• Less than 6cm may mean a difficult airway because you would assume the patient has an anterior larynx and less space for the tongue to be compressed out of the way by the laryngoscopy blade

Airway gadgets

Requirement of successful intubation

Proper equipment-Bag and mask,oxygen source-Airways oro and nasopharyngeal-Laryngosopes different blades-ETT different sizes-suction on

Management

I-History: previous history of difficulty is the best

predictorInquire about:-Nature of difficulty -No of trials -Ability to ventilate bet trials -Maneuver used -ComplicationsII-Snoring and sleep apnea( prdictors of DMV)

Examination

-Look for any obvious anomaly Morbid obesity(BMI) Skull Face Jaw Mouth,teeth Neck

Examination

I-The 3 joints movements A-O joint(15-20 degrees)Presence of a gap bet the Occiput and C1 is essential The cervical spine(range>90) T.M joint:-interdental gap(3 fingers) -subluxation (1 finger)

Examination

II-Measurements of the mandible-Thyro-mental distance (head extended)Normally 6.5 cmLess than 6 cm=expect difficulty

Tests to predict difficulty

Mallampatti test:Based on the hypothesisThat when the base of theTongue is disproportionallyLarge it will overshadow thelarynx

• MP Class I- Soft palate, tonsillar fauces, tonsillar pillars, and uvula

• MP Class II- Soft palate, tonsillar fauces, partial uvula

• MP Class III- Soft palate, base of uvula• MP Class IV- Hard palate only• MP III and MP IV are associated with greater

likelihood of a difficult airway.

-Simple easy test,correlates with what is seen during laryngoscopy or Cormack-Lehene grades ,but

1-moderate sensitivity and specificity(12% false +ve)2-Inter observer variation3-Phonation increases false negative view

II-Wilson test

-Consists of 5 easily assessed factors Body wight(n=0 ,>90=1,>110=2) Head and neck movement Jaw movement Receding jaw Buck teethEach factor assigned as o ,1 ,2 max is 10

Teeth

• Buck teeth and large incisors can interfere with blade placement. Loose teeth, loose crowns, cracked teeth, and chipped teeth must be documented beforehand.

• Ask if your patient has dentures, partials, or any other type of dental appliance that can be removed

Cervical Mobility

Ask the patient to turn her head from side to side, and up and down. Some patients cannot be placed in the “sniffing position” secondary to neck trauma, cervical collar, musculoskeletal disorders like kyphosis and rheumatoid arthritis. This prevents to place the patients head in the appropriate alignment that would allow for the best visualization of the airway.

Neck Circumference & Body Mass Index (BMI)

• A neck circumference of greater than 45cm in an obese patient with a BMI of greater than 40kg/m^2 is likely to be a difficult intubation.

• women with large pendulous breasts add a degree of difficulty to an intubation because the provider may not be able to position the blade handle appropriately toward the chest.

Facial Hair

• facial hair can mask other signs of a difficult

airway- like short thyromental distance. This is why you need to physically touch your patient’s neck when determining thyromental distance

Assess airway

• L- Look externally (facial trauma, teeth, facial hair, etc.)

• E- Evaluate thyromental distance• M- Mallampati Class• O- Obstruction (airway edema, tracheal mass,

mediastinal mass, etc.)• N- Neck mobility

Difficult airway

• Expected from history,examinationSecure airway while awake under LA

Unexpected different optionsPriority for maintenance of patent airway and

oxygenation

Airway gadgets

predictors of difficult mask ventilation

predictors of difficult mask ventilation

• Beard• Obese• Old Age• Toothless• Snores

Needle cricothyroidotomy

Confirm tube position

• Direct visualization of ETT between cords• Bronchoscopy ;carina seen• Continuous trace of capnography• 3 point auscultation• Esophageal detector device• Other as bilateral chest movement,mist in the

tube,CXR

Rapid sequence induction

• Indications: – Full stomach, cesarean section . Acute abdomine – Gastric band ---

• Technique: -Preoxygenation -IV induction with sux -Cricoid pressure -Intubate, inflate the cuff ,confirm position -Release cricoid and fix the tube

Complications of intubation

1-Inadequate ventilation2-Esophageal intubation3-Airway obstruction4-Bronchospasm5-Aspiration6- Trauma7-Stress response

Recommendations

• Adequate airway assessment to pick up expected D.A to be secured awake

• Difficult intubation cart always ready• Pre oxygenation as a routine• Maintenance of oxygenation not the intubation

should be your aim• Use the technique you are familiar with• Always have plan B,C,D in unexpected D.A

Thank you