RSI Airway Assessment New Hampshire Division of Fire Standards & Training and Emergency Medical Services

Introduction Slide

Purpose of this Module Review Airway Anatomy Learn Advanced Airway Assessment Techniques 3-3-2 Laryngoscope View Grading Mallampati Classifications BURP During this module the student will review the airway anatomy. The student will learn advanced airway assessment techniques not limited to Mallampati classification, Laryngosopic view grading, and the “3-3-2” airway grading method.

IF Endotracheal Intubation fails, you must have a back-up plan... King-LTD LMA BVM Combi-Tube Cricothyrotomy

Upper Airway Upper Airway The face and the facial skeleton and are considered components of upper the airway. The upper airway heats, humidifies and conducts air into the lower airways. Problems can arise from obstructions, fractures and soft tissue injuries.

Upper Airway http://www.bu.edu/av/courses/med/05sprgmedanesthesiology/Producer%20Lectures/anatomy/anatomy_files/airwa_3_files/airway%20anatomy_files/slide0028_image070.jpg

Middle Airway Middle Airway The middle airway consists primarily of the larynx. It is fairly well protected but is susceptible to injury. The larynx is comprised of cartilage and contains the vocal cords. Because it is narrow, edema, secretions, or foreign bodies can quickly cause problems. The rigid laryngeal structures are the hyoid bone, thyroid cartilage, cricoid cartilage and arytenoid cartilage. Inferior to the cricoid cartilage are tracheal cartilages. The cricoid cartilage is a complete ring and can be used to prevent passive reflux of stomach using cricoesophageal pressure (Sellick’s Maneuver) Laryngeal Cartilages The Cricothyroid artery is a small branch of the superior thyroid artery. It travels along the inferior border of the thyroid cartilage and becomes smaller as it reaches the midline. Cricothyroid puncture in the midline, inferior part of the membrane above the cricoid cartilage is least likely to produce bleeding. The large superior and inferior thyroid arteries supply the thyroid gland. The gland is highly vascular. A pyramidal lobe may extend to the hyoid bone. Puncture below the cricoid cartilage has increased risk of bleeding. Palpate the puncture site carefully and avoid any masses (Engel et al, 2001).

Thyroid versus Cricothyroid Cartilage Thyroid cartilage used in “BURP” maneuver. Does not form a complete ring around the trachea. Cricothyroid Cartilage used in CricoidPressure, does form a full ring around the trachea allowing for the compression of the esophagus.

http://www.bu.edu/av/courses/med/05sprgmedanesthesiology/Producer%20Lectures/anatomy/anatomy_files/airwa_3_files/airway%20anatomy_files/slide0011_image039.jpg

http://www.bu.edu/av/courses/med/05sprgmedanesthesiology/Producer%20Lectures/anatomy/anatomy_files/airwa_3_files/airway%20anatomy_files/slide0015_image047.jpg

Lower Airway http://www.aboutcancer.com/trachea_adam.jpg

1. Preparation A two-part process: Assess the risks Prepare the equipment

Assess the Risks

Difficult Airways - Assess the Risks “The difficult airway is something one anticipates; the failed airway is something one experiences.” -Walls 2002

How do you know if your patient is going to be difficult to intubate… …and does it really matter? ? In most pre-hospital cases the airway needs managing regardless of the level of difficulty, and the provider is expected to do that, regardless of difficulty ….so what is the benefit of knowing a fancy system?

Some Predictors of a Difficult Airway Dentures Limited jaw opening Limited cervical mobility Upper airway conditions Face, neck, or oral trauma Laryngeal trauma Airway edema or obstruction Morbidly obese C-spine immobilized trauma patient Protruding tongue Short, thick neck Prominent upper incisors (“buckteeth”) Receding mandible High, arched palate Beard or facial hair Trauma: immobilized – cannot align axis Peds: anterior and cephalad airway, large tongue, large occiput, small mouth, stiff/floppy epiglottis (more horizontal) Obesity or very small Short Muscular neck Large breasts Prominent Upper Incisors (Buck Teeth) Receding Jaw (Dentures) Burns Facial Trauma S/S of Anaphylaxis Stridor FBAO Blood Vomitus Epiglottis Dentures Tumors Impaled Objects Spinal Precautions Lack of adequate access

Additional Predictors: Medical History Joint disease Acromegaly Thyroid or major neck surgeries Tumors, known abnormal structures Genetic anomalies Epiglottitis Previous problems in surgery Diabetes Pregnancy Obesity Pain issues Rheumatoid Arthritis Ankylosing Spondylitis: Painful Stiffening of the joint Cervical Fixation Devices Klippel-Fiel Syndrome: Short wide neck, reduction in number of cervical vertebrae, and possible fusion of vertebrae. Thyroid or major neck surgeries Pierre Robin Syndrome: Small Jaw, cleft Palate, No Gag reflex, downward displacement of tongue Acromegaly: Thickening of Jaw, Soft tissue structures of the face, associated with middle age

Assess the Risk Identifying a potentially difficult airway is essential to preparing and developing a strategy for successful ETI and also preparing an alternate plan in the event of a failed ETI. The American Society of Anesthesiology (AMA) has noted: “… there is strong agreement among consultants that preparatory efforts enhance success and minimize risk.” And “…the literature provides strong evidence that specific strategies facilitate the management of the difficult airway “ Well, many Anesthesiologists have the option to “Abort” induction, or to work through a problem with as much assistance as needed. In the REAL WORLD of EMS that is seldom the case. However many of the BASIC principles are valid in the clinical evaluation of patients, and thus valuable in our education as medics. Knowing these principles will improve our decision making process and Patient Care;.

Objectives Identify 4 areas of airway difficulty Predict a difficult airway using the following mnemonics: MOANS LEMONS DOA

Airway Difficulties Difficult to ventilate with a BVM Difficult laryngoscopy Difficult to intubate Difficult to perform cricothyrotomy The four dimensions of difficult airways.

Difficult to Bag (MOANS) Mask Seal Obesity or Obstruction Age > 55 No Teeth Stiff

MOANS Mask Seal Small Hands Wrong Mask Size Oddly Shaped Face Bushy Beard Blood/Vomit Facial Trauma

Obesity or Obstruction MOANS Obesity or Obstruction Obesity Heavy chest Abdominal contents inhibit movement of the diaphragm Increased supraglottic airway resistance Billowing cheeks Difficult mask seal Quicker desaturation More dead space in cheeks Lower residual volumes

Obesity or Obstruction MOANS Obesity or Obstruction 3rd Trimester Pregnancy Increased body mass Quick desaturation Increased Mallampati Score Gravid uterus inhibits movement of the diaphragm

Obesity or Obstruction MOANS Obesity or Obstruction Obstructions Foreign Body Angioedema Abscesses Epiglottitis Cancer Traumatic Disruption/Hematoma/Burns

MOANS Age > 55 Associated with BVM difficulty, possibly due to loss of tone in the upper airway

MOANS No Teeth Face tends to “cave in” Consider leaving dentures in for BVM and remove for intubation

MOANS Stiff Refers to Poor Compliance Reactive Airway Disease COPD Pulmonary Edema/Advance Pneumonia History of Snoring/Sleep Apnea Also predicts a higher Mallampati score

Difficult Laryngoscopy & Intubation LEMONS Look Externally Evaluate 3-3-2 Mallampati Score Obstruction Neck Mobility Scene and Situation

LOOK Externally LEMONS Beards or facial hair Short, fat neck Morbidly obese patients Facial or neck trauma Broken teeth (can lacerate balloons) Dentures (should be removed) Large teeth Protruding tongue A narrow or abnormally shaped face http://library.thinkquest.org/5029/badbite2.jpg

Any single indicator has poor specificity LEMONS EVALUATE 3-3-2 Bottom of Jaw/Chin to Neck > 3 fingers Jaw/Palate > 3 fingers wide Mouth opens > 2 fingers wide Thyromental Distance Measure from upper edge of thyroid cartilage to chin with the head fully extended. A short thyromental distance equates with an anterior larynx that is at a more acute angle and also results in less space for the tongue to be compressed into by the laryngoscope blade. > 7 cm is usually a sign of an easy intubation < 6 cm is an indicator of a difficult airway Relatively unreliable unless combined with other tests Any single indicator has poor specificity

LEMONS EVALUATE 3-3-2 Mouth Opens at least 3 finger widths. Three finger widths thyromental distance. Two finger widths mandibulohyoid distance.

LEMONS EVALUATE 3-3-2 Will patients mouth open wide enough to accommodate 3 fingers? Will 3 fingers fit between the mentum and hyoid bone? Will 2 fingers fit between the hyoid and thyroid notch? If not, expect a difficult intubation

Mouth opens at least 3 fingers width? LEMONS Mouth opens at least 3 fingers width?

LEMONS Thyromental Distance Distance from the mentum to the thyroid notch. Ideally done with the neck fully extended. Can be done in-line Helps determine how readily the laryngeal axis will fall in line with the pharyngeal axis.

LEMONS Thyromental Distance If the thyromental distance is short, <3 finger widths, the laryngeal axis makes a more acute angle with the pharyngeal axis and it will be difficult to achieve alignment. Less space to displace the tongue. http://www.anesth.utmb.edu/cohen/preintubation_evaluation_files/image002.jpg

Thyromental Distance-3 fingers? LEMONS Thyromental Distance-3 fingers?

Mandibulohyoid Distance- 2 fingers? LEMONS Mandibulohyoid Distance- 2 fingers? Measured from the mentum to the top of the hyoid bone. The epiglottis arises from the thyroid and remains dorsal to the hyoid bone. Therefore, the position of the hyoid bone marks the entrance to the larynx. http://www.achi.com/images/inthewuscope/0101438g.jpg

Mandibulohyoid Distance LEMONS Mandibulohyoid Distance

Mandibulohyoid Distance LEMONS Mandibulohyoid Distance When the position of the hyoid bone is caudal or relatively caudal, a large portion of the tongue is situated in the hypopharynx instead of the mouth. During laryngoscopy, this large hypopharyngeal tongue mass further compromises the compliance needed for its displacement

Mandibulohyoid Distance LEMONS Mandibulohyoid Distance Patients who have a longer mandibulohyoid distance, greater then 2 finger widths, tend to be more difficult to intubate. A more caudal hyoid bone thus indicates a relatively caudal larynx.

LEMONS Upper & Lower Face Measure the size of the upper face as compared to the lower face. Should be roughly the same. If the lower face is longer than the upper face then you should anticipate some degree of difficulty lining up the structures.

Upper and lower face equal? LEMONS Upper and lower face equal?

Upper and lower face equal? LEMONS Upper and lower face equal?

LEMONS Mallampati Score http://www.bu.edu/av/courses/med/05sprgmedanesthesiology/Producer%20Lectures/anatomy/anatomy_files/airwa_3_files/airway%20anatomy_files/slide0028_image070.jpg

LEMONS Mallampati Score Have patient sit up, and stick out tongue without phonating May be unable to properly assess this in an emergent field situation Modified version is to use a laryngoscope blade like a tongue blade to visualize the oropharynx – (not as sensitive or specific)

Mallampati Classification LEMONS Mallampati Classification Relates to tongue size to pharyngeal size. Performed with patient in a sitting position, head neutral, mouth open wide and tongue protruding to the maximum. The Subsequent Classification is assigned based upon the pharyngeal structures visible.

Mallampati Classification LEMONS Mallampati Classification Class I: Visualization of the soft palate, fauces, uvula, and anterior & posterior pillars

Mallampati Classification LEMONS Mallampati Classification Class II: Visualization of the Soft palate, fauces and uvula.

Mallampati Classification LEMONS Mallampati Classification Grade III: Visualization of the soft palate and the base of the uvula.

Mallampati Classification LEMONS Mallampati Classification Grade IV: The soft palate is not visible at all.

LEMONS Pt should be sitting, head in neutral position, mouth wide open, and tongue extended out as far as possible. The number classification is based on the structures that are visible. A Class I view is a Grade I Intubation 99% of the time A Class IV view is a Grade III or IV intubation 99% of the time Class IV: <1% prevalence (hard palate only visible) Severe Difficulty Intubating Class III: <13% prevalance (soft palate, base of uvula visible) Moderate Difficulty Intubating Class II: 40% prevalence (soft palate, uvula, fauces visible) No Difficulty Intubating Class I: 46% prevalence (soft palate, uvula, fauces, pillars visible) No Difficulty Intubating

Mallampati Classification LEMONS Mallampati Classification

LEMONS Obstruction Laryngoscopy or intubation may be more difficult in the presence of an obstruction Anatomy Trauma Foreign body obstruction Edema (burns)

Obstructions Laryngoscopic View Grades LEMONS Obstructions Laryngoscopic View Grades Grade 1: Full aperture visible Grade 2: Lower part of cords visible Grade 3: Only epiglottis visible Grade 4: Epiglottis not visible

Obstructions Laryngoscopic View Grades LEMONS Obstructions Laryngoscopic View Grades Graded in order from the best view to worst. Grade 1: Visualization of the entire laryngeal apeture

Obstructions Laryngoscopic View Grades LEMONS Obstructions Laryngoscopic View Grades Grade 2: Visualization of just the posterior portion of the laryngeal aperture. Grade 3: Visualization of only the epiglottis Grade 4: Visualization of the soft palate only.

Obstructions Laryngoscopic View Grades LEMONS Obstructions Laryngoscopic View Grades A severe grade III or IV view with failed endotracheal intubation occurs in 0.05-0.35% of patients

Cormack & Lehane Grading LEMONS Cormack & Lehane Grading Grade I =  success & ease of intubation 10-30% Grade I: full aperture is visible Grade II: Lower portion of cords visible Grade III: Epiglottis only visible Grade IV: Epiglottis not visible Grades III & IV are rare. So, if you frequently see Grade III or IV – consider revisiting your technique. <5% <1% % listed = incidence

LEMONS Neck Mobility Ideally the neck should be able to extend back approximately 35° Problems: Cervical Spine Immobilization Ankylosing Spondylitis Rheumatoid Arthritis Halo fixation

Scene and Situation (SEE) LEMONS Scene and Situation (SEE) Scene safety Environment Do you have a reasonable chance to get the tube? Space, positioning, access Egress Will you be able to ventilate during egress? A respiratory rate of 4 is better than a rate of 0! Enough meds for a long extrication?

Difficult Cricothyrotomy DOA Difficult Cricothyrotomy DOA Disruption or Distortion Obstruction Access Problems If you can’t bag and can’t cric, they’re DOA

Disruption / Distortion DOA Disruption / Distortion Distortion Surgeries Radiation Therapy Scarring Burns

Disruption / Distortion DOA Disruption / Distortion Disruption Hanging Crush Injuries Penetrating Trauma Other Soft Tissue Trauma Burns Laceration

DOA Obstructions Hematoma Abscess Tumor Tumors can also create distortions & extra bleeding

DOA Access Issues Obesity Halo Short neck SC Emphysema Bushy beard Flexion deformity of the spine

“BURP” – a.k.a. “External Laryngeal Manipulation” Backward, Upward, Rightward Pressure: manipulation of the trachea 90% of the time the best view will be obtained by pressing over the thyroid cartilage 90% of the time the best view will be obtained by pressing over the thyroid cartilage – because, anatomically, the vocal cords are connected here. “BURP”-backwards, upwards, right, pressure May help with difficult intubation Differs from the Sellick Maneuver

To Summarize Airway assessment is a critical part of the RSI process The difficult airway assessment must be performed prior to ALL RSI attempts. While this criteria helps identify difficult airways, it does not guarantee an easy intubation—Be Prepared!