Airway evaluation and Management By :Dr. Adel Elshimy

Lecture Objectives Students at the end of the lecture will be able to :  Describe the applied anatomy of the airway.  Conduct a preoperative airway assessment.  Identify a potentially difficult airway.  Learn about management of airway obstruction.  Become familiar with airway equipment.  Understand issues around aspiration prophylaxis.  Become familiar with controlled ventilation.  Appreciate ways of monitoring of ventilation and oxygenation.

AIRWAY CONTROL Opening the Airway Jaw thrust Head tilt–chin lift

AIRWAY CONTROL Oropharyngeal Airway

Mask Ventilation Oral airway Oral airway Two-handed technique Two-handed technique

AIRWAY CONTROL Oropharyngeal Airway (cont.)

AIRWAY CONTROL Nasopharyngeal Airway (cont.)

OXYGENATION AND VENTILATION Bag-Valve-Mask (cont.) With oxygen reservoir

Esophageal-Tracheal Combitube A = esophageal obturator; ventilation into trachea through side openings = B C = tracheal tube; ventilation through open end if proximal end inserted in trachea D = pharyngeal cuff; inflated through catheter = E F = esophageal cuff; inflated through catheter = G H = teeth marker; blindly insert Combitube until marker is at level of teeth Distal End Proximal End B C D E F G H A

Usage

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

Airway Anatomy Innervation Innervation Vagus n. Vagus n. Superior laryngeal n. Superior laryngeal n. External branch – motor to cricothyroid m. External branch – motor to cricothyroid m. Internal branch – sensory larynx above TVC’s Internal branch – sensory larynx above TVC’s Recurrent laryngeal n. Recurrent laryngeal n. Right – subclavian Right – subclavian Left – Aortic arch (board question) Left – Aortic arch (board question) Motor to all other muscles, Sensory to TVC’s and trachea Motor to all other muscles, Sensory to TVC’s and trachea

Management I-History: previous history of difficulty is the best predictor previous history of difficulty is the best predictor Inquire about:-Nature of difficulty -No of trials -No of trials -Ability to ventilate bet trials -Ability to ventilate bet trials -Maneuver used -Maneuver used -Complications -Complications II-Snoring and sleep apnea( prdictors of DMV)

LEMON -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:  -subluxation (1 finger)

Examine Airway The 3 – 3 – 2 rule Mouth open: 3 fingers Mouth open: 3 fingers Mentum to hyoid: 3 fingers Mentum to hyoid: 3 fingers Floor of mouth to thyroid cartilage: 2 fingers Floor of mouth to thyroid cartilage: 2 fingers

Examine Airway Mouth open : 3 fingers Mouth open : 3 fingers Allows insertion of tube, laryngoscope Allows insertion of tube, laryngoscope Mentum to hyoid : 3 fingers Mentum to hyoid : 3 fingers Predicts ability to lift tongue into mandible Predicts ability to lift tongue into mandible

Mallampatti Mallampatti test: Based on the hypothesis That when the base of the Tongue is disproportionally Large it will overshadow the larynx

-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 variation 3-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 teeth Each factor assigned as o,1,2 max is 10

Obstruction Apparent cause e.g. goitre Apparent cause e.g. goitre OSA OSA Noisy breathing or stridor Noisy breathing or stridor Signs of upper airway obstruction Signs of upper airway obstruction Other causes Other causes

Neck Mobility Prior condition Surgery Surgery Rheumatoid arthritis Rheumatoid arthritis Osteoarthritis Osteoarthritis Others Others

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

Airway gadgets

Mask Ventilation Induction of anesthesia produces upper airway relaxation and possible collapse Induction of anesthesia produces upper airway relaxation and possible collapse Downward displacement of mask with thumb and index finger Downward displacement of mask with thumb and index finger

Requirement of successful intbatin 1-Normal roomy mandible 1-Normal roomy mandible 2-Normal T-M, A-O, and C-spine 2-Normal T-M, A-O, and C-spine

Positioning for successful intubation 3-Alignment of 3 axes or Assuming sniffing position -Any anomaly in these 3 joints A-O, T-M or C-spine can result In difficult intubation

Endotracheal Intubation Look for epiglottis Look for epiglottis If initially not found insert laryngoscope further If initially not found insert laryngoscope further If this maneuver does not work slowly pull laryngoscope back If this maneuver does not work slowly pull laryngoscope back Once epiglottis visualized, push laryngoscope into vallecula and apply traction at 45 degree angle to “push” epiglottis up and out of the way Once epiglottis visualized, push laryngoscope into vallecula and apply traction at 45 degree angle to “push” epiglottis up and out of the way

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

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

Cricoid pressure Cricoid Pressure

Complications of intubation 1-Inadequate ventilation 2-Esophageal intubation 3-Airway obstruction 4-Bronchospasm5-Aspiration 6- Trauma 7-Stress response

Difficult airway Causes Causes-Congenital-Acquired

Airway gadgets

Rigid Fiberoptic Scope Bullard Wu Scope

Rigid Fiberoptic Scope Rigid Fiberoptic Scope Upsher GlideScope

Difficult airway Expected from history,examination Expected from history,examination Secure airway while awake under LA  Unexpected different options Priority for maintenance of patent airway and oxygenation

Transtracheal Jet Ventilation

Ventilation Spontaneous ventilation Spontaneous ventilation Controlled ventilation Controlled ventilation Minute volume divider Minute volume divider -Tidal volume 10 mls/kg -Respiratory rate to maintain normocarbia -I:E ratio

Recommendations Adequate airway assessment to pick up expected D.A to be secured awake Adequate airway assessment to pick up expected D.A to be secured awake Difficult intubation cart always ready Difficult intubation cart always ready Pre oxygenation as a routine Pre oxygenation as a routine Maintenance of oxygenation not the intubation should be your aim Maintenance of oxygenation not the intubation should be your aim Use the technique you are familiar with Use the technique you are familiar with Always have plan B,C,D in unexpected D.A Always have plan B,C,D in unexpected D.A

References Anesthesia and resuscitation Anesthesia and resuscitation Dr. H.Braden Dr. H.Braden chapters 1,2 Airway and ventilation chapters 1,2 Airway and ventilation  Lecture notes on clinical anesthesia Carl Gwinnutt Carl Gwinnutt 2 nd edition 2 nd edition Chapter 2 page 18-29

Dr. Adel Elshimy Date: 18/10/2011 T hank You T hank You