Airway Airway managementmanagement

Dr Saurav DasDr Saurav Das

When you cannot breath nothing else matter When you cannot breath nothing else matter

• nose ANATOMY OF AIRWAY : The airway commences at the and extends upto the terminal bronchioles.

• • NOSE ; It can be divided into external and internal nasal cavity.• EXTERNAL NOSE ; It has a bony part made of nasal bones nasal parts of

frontal bones and frontal process of maxilla.It has also a series of cartilage in the lower part and a small zone of fibro-fatty tissue forming ala of the nose.

• INTERNAL NOSE :The cavity of the nose is subdivided into two parts by the septum which opens exteriorly into nares and posteriorly into nasopharynx through choanae.

• Each side of the nose presents a roof,a floor a medial and a lateral wall.• Roof :It slopes upward and backward to form the bridge of the nose (nasal

and frontal bones), has a horizontal part (ciribriform part of ethmoid) and finally a downward slopping segment (the body of the ethmoid).

• FLOOR : It is concave from side to side is formed by the palatine process of maxilla and the horizontal plate of palatine bone’

• The medial wall :It comprises of the septum formed by septal cartilage .perpenicular plate of ethmoid and the vomer.

• The lateral wall ;It has a bony framework made up of nasal aspect of ethmoidal labyrinth above, the nasal surface maxilla below and infront , and a perpendicular plate pf palatine bone behind it.It has three conchaes each arching over a meatus.

• PHARYNX :It is a wide fibromuscular tube which joins the oral and nasal cavity in front to the larynx below it. It extends from the basilar part of the skull to the origin of the oesophagus at the level of C6 vertrebra .It is divided into nasopharynx, oropharynx and laryngopharynx

• Nasopharynx : It lies behind the nasal cavity above soft palate.It communicates with the oropharynx through pharyngeal isthmus which is closed during deglutition by lifting soft palate.The nasopharyngeal tonsil is primary cause of obstruction in this region.

• Oropharynx :The mouth cavity leads to oropharynx through the oropharyngeal isthmus which is bound by the soft palate,palatoglossus arches and the dorsum of the tongue.

• Laryngopharynx It extends from from the tip of the level of C6.Structurally the larynx consists of framework of articulating cartilages linked together by ligaments which moves in relation to each other by the action of laryngeal muscles .

• Laryngeal cartilages :thyroid, cricoid , paired arytenoids with epiglottis ,corniculate and cuneiform cartilages.

• Trachea It extetends from the lower border of cricoid cartilage to its termination at the bronchial bifurcation. It is about 15 cm long in adult and diameter corresponds to that of patient index finger’.

DEFINATIONS OF DEFINATIONS OF ABNORMAL AIRWAYABNORMAL AIRWAY

• DIFFICULT AIRWAY: In clinical situation where a conventionally trained anesthesiologist experiences difficulty in mask ventilation, difficulty with tracheal intubation , or both.

DIFFICULT MASK DIFFICULT MASK VENTILATION ;VENTILATION ;

• It is not possible for the unassisted anesthesiologist to maintain the SPO2 >90 % using 100% O2 and positive pressure mask ventilation in a patient whose SPO2 was >90% before anesthetic intervention .

• It is not possible for the unassisted anesthesiologist to prevent or reverse signs of inadequate ventilation during positive pressure mask ventilation

• DIFFICULT LARYGOSCOPY :• It is not possible to visualize any

portion of the vocal cords with conventional laryngoscopy.

• DIFFICULT INTUBATION :• Proper insertion of the tracheal

tube with conventional laryngoscope requires more than three attempts of or more than 10 mins.

FOLLOWING FACTORS CAN FOLLOWING FACTORS CAN COMPLICATE AIRWAY IN COMPLICATE AIRWAY IN OBSTETRICS PATIENTSOBSTETRICS PATIENTS

• Increased body weight• Large breast• Increased mucosal edema and

vascularity• Increased risk of aspiration• Coexisting systemic disease• Badly placed hip wedge• Increased O2 consumption• Decreased O2 store

• The essential components of airway assessment:

• History taking• General ,physical &regional

examination• Physical indices• Radiological evaluation

• HISTORY TAKING• Review prior anesthetic records• Ask the patient about the problems prior to anesthesia

such as jaw pain, hoarseness of voice ,dental injury etc._that may suggest difficult intubation.

• If the patient was informed by the anesthtetist that he was difficult to ventilate or intubate.

• The condition ,the pt had earlier might have worsened.• History suggestive of following disorder: diabetes,

obstructive sleep apnoea , obesity. rheumatoid arthritis, zenker diverticulum,acromegaly,pregnancy,anaphylaxis,mediastinal masses,xepiglottis,the airway in HIV patient,Ludwig,s angina,retropharyngeal abscess.

•

• EXAMINATION;• GENERAL, PHYSICAL AND REGIONAL A

global assessment should include the following:

• Age , height, bodyweight, mouth opening, teeth, palate, ability to protrude the lower jaw, measurement of sub mental space, patient neck ,general body habitus,infection of airway, systemic diseases etc.

• Following patients are difficult to Ventilate

• Obese• Bearded• Elderly• Snorers • Edentulous• An image of snoring santa just about

sums it up..

• • LEMON OR MELON PHYSICAL

SIGN• look externally• evaluate 3-3-2-1 rule• mallampati score • obstruction• neck mobility

• Evaluate 3-3-2-1• 3 finger between the patient’s

teeth• 3 finger under chin• 2 finger on the top of notch• 1 finger lower jaw for

ant.subluxation

Mallampati scoreMallampati score• Class1 -Visualization of soft

palate,fauces,uvula and both ant. And post. Pillars.

• Class2- Visualization of the soft palate ,fauces and uvula.

• Class-3 Visualization of soft palate and the base uvula

• Class -4 visualization of hard palate only

CORMACK AND LEHANE CORMACK AND LEHANE LARYNGOSCOPIC VIEWLARYNGOSCOPIC VIEW

• Grade 1 visualization of entire laryngeal aperture

• Grade 2 visualization of only posterior commissure

• Grade 3 visualization of only epiglottis

• Grade 4 visualization of just soft palate

• LM –MAP RULE• Look for external face

deformities• Mallampati• Measurements 3-3-2-1 • A –O extension• Pathological obstructive

condition

• FOUR DS to suggest a difficult airway

• Dentition • Distortion• Disportion • Dysmotility

• Airway assessment-deduction derive • whether the airway can be maintained with

mask• whether mask ventilation is sufficient or

intubation would be needed• If intubation is needed, can it be performed

safely with the patient anesthetized or an awake intubation would be necessary

• Whether the patient can be safely paralyzed or spontaneous respiration needs to be maintained

• If nasal intubation is needed,if whether a direct view is possible or must it be blind.

• MAGBOUL 4M & Ms• Malampati• Measurment• Movement• Malformation of skull,teeth,

obstruction, pathology

• PATIL TM DISTANCE TEST• <6 cm = difficulty• 6-6.5 cm =less difficult• >6.5 = normal• STERNOMENTAL DISTANCE• Normal distance is 12.5 cm

• Cass and James’s 6 common anatomical anomaly

• Short muscular neck with full set of teeth • Receding jaw with an obtuse mandibular

angle• Protruding upper incisor• Poor mobility of the mandible• Long and high arched palate• Increased alveolar mental ridge distance

requiring wide opening of the mandible for insertion of laryngoscope

• UPPER LIP BITE TEST• Reflects subluxation of temporo

mandibular joint• RHTMD• The ratio of height to

temporomandibular distance • The optimal cut off point for

RHTDM was 23.5

• RADIOLOGICAL EXAMINATION OF THE AIRWAY

• To see whether there is • Increased posterior depth of the

mandible• Increased anterior depth of the

mandible• Reduction in the distance between

occiput and spinous process c1

• Difficult airway cart-contents– Face mask –all sizes– Endotracheal tube– Tongue depressor– Stylets– Laryngoscope– Airways– Magill,s forceps– Suction apparatus– Oxygen source– A ventilating apparatus– A head rest– LMA – Flexible fibreoptic laryngoscope– Trcheostomy kit– Equipment for retrograde intubation– Combitube

• FASE MASK VENTILATION AND TECHNICQUE• Anaesthesia face mask are rubber or plastic

employed to administer oxygen or to ventilate the nonintibuted patient.

• The mask should be hold with index and thumb and other three fingers to pull the mandible upward.

• Mandibular displacement along the cervical extension and chin lift, all tend to pull the tongue and soft tissue up of posterior pharyngeal wall and relieve the obstruction of airway in anesthetized patient.

• Some time, it may be required to hold the mask with two hands and vigorously pulling the mandible upward .

• AIRWAYS• When airway integrity can be maintained with

manipulation of mask, mandible or neck a airway of appropriate size can restore the patency .Air way are two types – oral and nasal.

• Appropriate size of airway corresponds to distance between angle of mouth to angle of mandible. The airway may be inserted right side up or up side down than rotated 180 degree into the position of function.

• Nasal airways are useful in patient who are not deeply anesthetized because such airway tends to provoke less airway stimulation.

• LARYNGOSCOPE• The standard rigid laryngoscope

consist of a detachable blade with removable bulb that connects to a battery containing handle. Some commonly used blades are

• Macintosh curved blade• Straight millers blade• Mc coy blade with a flexible tip

• Magill,s forcep• Uses:• To remove any foreign body• To introduce rye,s tube• To put pharyngeal pack•

MAGILL,S FORCEPSMAGILL,S FORCEPS

• ENDOTRCHEAL TUBE• Most commonly used endotracheal

tubes are now a days transparent and made of PVC.

• Cuffs with the tubes are high volume low pressure cuff. cuff pressure should be less than 20-25mmhg since perfusion pressure of tracheal mucosa is 25 to 35 mmhg

• E T TUBES

Technique of laryngoscopy Technique of laryngoscopy and intubationand intubation

• In every case ,the anesthesiologist must attempt to determine whether mask ventilation will be possible if the patient anesthetized and paralysed.

• The usual sequence of intubations are• For intravenous inducton a rapidly acting anesthetic

is first administered after preoxygenation for three minutes.The drug can be one of them

• Thiopental,propofol,rapidly acting barbiturates,ketamine

• A muscle relaxant is used to facilitate the laryngoscopy.It can be depolarizing or non depolarizing

• the head is maintained in classic sniffing position to align the oral ,pharyngeal and laryngeal axes.

• Laryngoscope to be held with left while the fingers of the right hand are used to open the mouth.

• The laryngoscope blade is inserted gently into the right side of the patient mouth to avoid the incisor teeth and to enable the flange of the blade to keep the tongue to left.

• After visualization of epiglottis the curved blade is placed into vallecula and with the full finger grip hand the laryngoscope to pull forward and upward

• A gentle dorsal pressure on cricoid or BURP maneuver of thyroid cartilage may improve the glottic exposure.

• Endotracheal tube is inserted into the right side of the mouth and placed between open vocal cords under direct vision.

• In man, the tube is generally inserted about 23 cm at the lips and women it is 21cm when tip of the tube is at 4cm above the carina.

• Cuff if inflated with air so that there is no audible leak.

• Following are the signs that tube is in proper position

• Both side equal air entry on auscultation

• Air column in tube• And by capnography

RAPID SEQUENCE RAPID SEQUENCE INDUCTIONINDUCTION

• Steps are• Preoxygenate at least for four

vital capacity breaths• IV anesthetics and relaxants are

given together• Apply cricoid pressure when

patient is unconscious.• Ventilation prior to laryngoscope

is omitted here.

LARYNGEAL MASK LARYNGEAL MASK AIRWAYAIRWAY

• Technique of insertion• Sniffing the morning air head position• Lubrication of the posterior part only• The index finger of the operator’s hand may

be used to guide LMA over the back of tongue

• The tip of the cuff is pressed posteriorly against the hard palate

• The back longitudinal line on the shaft on the LMA should face midline of the upper lip

• IIPV is accompanied by an audible leak

• THE COMITUBE• It is double lumen tube that is inserted

blindly. The esophageal lumen has a closed distal end. while inserting , the tongue and mandible are lifted with one hand and introduce the tube in the direction of normal curvature of pharynx with the another hand

• Pharyngeal cuff is inflated with 100ml of air and distal end with 15ml.Ventilation is started with the longer tube because placement is usually esophagus. If there is no signs of lung ventilation and stomach being inflated ,ventilation should be started with second tube.

COMBITUBECOMBITUBE

• NEEDLE CRICOTHYROTOMY• In the event of inability to

intubate the trachea or ventilate the lung needle cricothyrotomy or tracheotomy are final steps.

•

• Advantages of cricothyrotomy over tracheotomy are

• Can be performed in lateral position

• Easier to perform• Less instrumentation is needed• Takes shorter time

• Procedure• It is performed by by placing a 12-14 gauge

needle or catheter through cricothyrroid membrane into the trchea. An alternative site is the subcricoid region beween the cricoid cartilage and the first tracheal ring.The needle is fixed with an artery forcep.Intermittent pressurized oxygen provides the most suitable method for ventilation through this small needle and simplest method is to use emergency oxygen flush.