ANESTHESIS SHOULD KNOW
1) Anatomy, nerve innervation,phatologic cond. & method of assessment.
2) Physiologic consequences & complication.
3) Anticipate pt. with difficult airway.
4) Formulate & implement alternative plan in various clinical situation.

History
Sn/Sm suggest abnormal airway
•SOB
•Hoarsenes ( rheumatoid artritis- criocotenoid cartilage – narrowing Lx opening.)
Previous surgery, trauma, neoplasia of airway

Previous anesthetic record.

Physical examination

1) Head shape- micrognathia,mandibular hypoplasia
2) protruding teeth(edentulous)- disturb seal mask, loose, capped, prosthetic teeth.
3) Cleft, high-arch palate
4) Large big tongue( trisomy 21, mucopolysaccharidoses, beckwith-weidemann syndrom)

5) Prediction difficulty trachea intubation by:
•Mallampati classification
•Temporomandibular joint mobility
( ankylosis,long term type1 DM, pain due to trauma)
•Distance lower border mandible to thyroid notch > 6.5 cm (adult)

INDICATIONS OF INTUBATION
1) Inabiliy to oxygenate patient (SpO2 <>
2) Inability to ventilate patient (rising PaCO2, respiratory acidosis, mental status change or other symptoms)
3) Patient unable to protect the airway.

CONTRAINDICATIONS
1) Neck immobility or increased risk of neck trauma (e.g. rheumatoid arthritis, cervical spine injury, etc.)-consider fiberoptic intubation.
2) Inability to open mouth (e.g. trismus, scleroderma, surgical wiring, etc.)- consider nasal intubation, either blind or fiberoptic, or surgical airway.

Airway equipment

1) Mask
2) Airways
3) Laryngoscopes
4) Endotracheal tubes + stylet.
•Adult male: 7.0,7.5,8.0
•Adult female: 6.5,7.0,7.5
•Children > 1 year age
size= (age(yr) +16 )/ 4
5) Length of tube cm= 12 + (age/2)
6) Suction.

endotracheal tube

laryngoscope

type of larynscope

Technique For Orotracheal Intubation
- Assemble equipment
- Calculate doses and draw medications into syringes
- Check IV access and flush fluid
- Preparation And Equipment (Always Have Suction Available)
- Head Position - Alignment Of Oral, Pharyngeal, and Laryngeal Axes ,(sniffing position)
- Choice Of Laryngoscope And Endotracheal Tube

Induction agent

Etomidate
dose- 0.3 mg/kg
advantage-Good for low blood pressure; okay in hypovolemia
cautions- Nausea and vomiting on emergence

Ketamine
dose- 1.5 mg/kg
advantage- Good for low blood pressure, hypovolemia; good in asthma
Caution in elevated intracranial pressure or heart disease

Propofol
dose- 2 - 2.5 mg/kg
advantage- Rapid onset and recovery
Caution if hypovolemic or risk of hypotension

Thiopental
dose- 3 - 5 mg/kg
advantage- Multiple drug interactions

caution if hypovolemic or risk of hypotension

Muscle relaxant

Succinylcholine
dose 1 - 1.5 mg/kg
characteristic- Rapid onset, rapid recovery; fasciculation
Contraindicated in hyperkalemia, crush injury, renal failure, extensive burns, elevated intracranial or intraocular pressure

Rocuronium
dose 0.6- 1.2 mg/kg
characteristic- No fasciculation
cautions- Longer acting-may be problematic if intubation attempt fails

Vecuronium
dose 0.08 - 0.1 mg/kg

Atracurium
dose 0.4 - 0.5 mg/kg

Orotracheal Intubation

- Patient’s Head At The Level Of The Xiphoid
- Sniffing Position
- Laryngoscope In LEFT Hand
- Open Mouth

- Hold Tracheal Tube In Right Hand Like A Pencil

Laryngoscopic View Grades
Laryngoscopic view may be clasified into four grades:

Grade I = visualization of the entire laryngeal aperture.


Grade II = visualization of just the posterior portion of the laryngeal aperture.

Grade III = visualization of only the epiglottis.
Grade IV = visualization of just the soft palate only, not even the epiglottis is visible.

Laryngoscopic View Grades
Grade II or III laryngoscopic views are relatively common and occur in 1 to 18% of surgical patients. The Grade III view occurs in about 1-4% of patients. A severe grade III or grade IV view with failed endotracheal intubation occurs 0.05 of 0.35% of patients.
It may be helpful to the next anesthesiologist to record both the grade of laryngoscopic view achieved, the patient position and the technique.

Laryngoscopic View Grades

Alternatives To Orotracheal Intubation Under Anesthesia
Awake Orotracheal Intubation
Nasotracheal Intubation - Awake Blind Nasal - Nasotracheal Intubation After Induction
Intubation With Fiberoptic Bronchoscope
- Awake versus Under Anesthesia
- Orotracheal versus Nasotracheal
Retrograde Intubation

Verification Of Correct Tube Placement
- The most reliable method for determination of tube placement is direct vision of the endotracheal tube passed through the vocal cords
- Symmetric Chest Movement
- Symmetric Breath Sounds
- End tidal Carbon Dioxide - Greater Than 30 For 3-5 Breaths
- Condensation Of Water In The tube
- Palpation Of Cuff In Suprasternal Notch
- Fiberoptic Bronchoscopy

RAPID SEQUENCE INDUCTION
Sequence and rapid method of securing airway, to minimizes aspiration in process of intubation
•Pt preoxygenated for 5 minutes / 4 max deep breath within 30 scd/ 3 vital capacity breath 100% O2.
•No assisted breathing until airway isolated
•Nondepolarizing MR - scolin
•Applied cricoid pressure (sellick’s maneuver)
*All process should be completed in 60 sc post induction

Complication of endotracheal intubation
During intubation
•Laryngospasm
•Laceration,bruising lips,tongue,pharynx
•#,chipping,dislogement of teeth
•Perforation trachea,esophagus
•Retropharyngeal dissection
•# or dislocation cervical spine
•Trauma to eyes
•Haemorrage
•Bactremia
•Aspiration gastric content/ FB
-Endobrachial or esophageal intubation
-Dislocation arytenoid cartilages or mandible
-Hypoxemia, hypercarbia.
-Bradycardia, tachycardia
-Hypertension
-Increased intracranial or intraocular pressure

Complication with tube insitu
-Accidental extubation
-Endobrachial intubation
-Obstruction / kinking
-Bronchospasm
-Ignation of tube by laser device
-Aspiration
-Sinusitis
-Excoriation of nose or mouth

Complication after extubation
-Laryngospasm
-Aspiration –gastric content, blood, FB
-Glottic,subglottic, uvular edema
-Dysphonia,aphonia
-Paralysis of vocal cord, hypoglossal,lingual nerves
-Sore throat
-Noncardiogenic pulmonary edema
-Laryngeal incompetance.
-Soreness, dislocation jaw
-Tracheomalacia
-Glottic,subglottic or tracheal stenosis
-Vocal cord granulomata.