Anatomy• Vocal cords divide the airway into upper and lower airway• Opening between the two vocal cords is called Glottis• Glottis is the narrowest part in an adult airway
Age Considerations- Infant airway• Large occiput• Tongue relatively larger• Larynx is higher in the neck (C3 in infants, C4- C5 in adults)• Subglottic area is the narrowest part• Trachea is placed more anteriorily• Young infants have relatively less oxygen reserve (greater oxygen consumption), so hypoxemia occurs more rapidly
Physiologic changes- Pregnancy• Generalized edematous state which also affects tongue & supraglottic soft tissue• Mucosal engorgement- Bleeding & swelling• Increased gastric emptying time & diminished LES tone- Risk of aspiration• Incidence of Mallampati class 3 increases as pregnancy progresses• Hypoxemia occurs more rapidly.
Problems with the emergency airway• Unexpected• Little time• Panic• Risk of Aspiration high• Trauma: Facial injuries Head injuries C-Spine injuriesAll the above situations makes it difficult to secure the airway
Oropharyngeal airway• Contraindicated in patients with gag reflex.
Nasopharyngeal airway • Contraindicated in patients with basal skull #
Bag-Valve-Mask, pocket maskTechniques:• Mouth - to - Mask• One person BVM• Two person BVM• Three person BVM• PPV: Forcing air into a patient, (with a positive pressure) who is breathing inadequately or not breathing at all
INTUBATIONWhen does the patient need it? • Unconscious/semiconscious patient with GCS <9 • Respiratory failure (snake bite, drug overdose) • All gasping patients • Cardiac arrest • Anaphylaxis • Pulmonary edema/ARDS for Positive pressure ventilation • Before gastric lavage, in poisoning patients with low GCS
Purpose of intubation • To maintain a patent airway • To maintain adequate oxygenation • Protect from aspiration • For positive pressure ventilationNote: It is the most definitive means of achieving complete control of the airway
Airway assessment before intubating(elective) • Look for size of teeth • Size & mobility of the jaw • Mobility of C-spine (avoid in trauma) • Short neck • Obesity / pregnancy • Mallampati class
Choose the appropriate ETT size • Adult males 7.5 - 8.5 • Adult females 7 – 8 • For pediatric patients (1- 8 years) ETT size= 4 + (age in years) 4 • Use uncuffed tubes in patients <8 years • Subtract 0.5 for the appropriate size cuffed ETT
Intubation procedure• Position : (sniffing position) • Flexion at lower neck • Extension at atlanto-occipital joint, if there is no C- spine injury.• Suspected C- spine injury: • Manual in line stabilization should be done
Procedure• Pre oxygenate the patient adequately, with 100% oxygen using BVM• Hold laryngoscope in left hand and insert laryngoscope blade into the right side of mouth and sweep the tongue to left• Lift the handle tangentially at 90o to the blade• Visualize vocal cords (BURP technique)
BURP technique• Applying Backward, Upward and Rightward Pressure over the lower third of thyroid cartilage for proper visualization of the vocal cords during intubation
GlottisVisualize the tube going through this structure
Procedure• After inserting the tube• Take out the stylet, inflate cuff• Ventilate patient through tube and confirm breath sounds over epigastrium and 4 lung fields. (5 point auscultation)• If tube is placed properly, secure the tube in place.
Rapid Sequence Intubation Combined administration of sedative &neuromuscular blocking agent to facilitate tracheal intubation.
Rapid Sequence Intubation• RSI should not be used in patients who do not need pharmacological adjuvants for intubation such as those with agonal respirations or cardiac arrest• Do not give RSI medication in whom laryngoscopy is likely impossible (Ex: Angioedema, Mallampati class 3 and 4)
Rapid Sequence IntubationPreoxygenation:• Hyperventilate at 20-24 breaths per minute with 100% O2, using BVM with a reservoir bag.• Attain a saturation of over 95% before administering any drugs.• Perform Sellick’s maneuver before administering the first RSI agent, and should be maintained until tube is passed and cuff inflated
Special considerations• Give Atropine 0.02 mg/kg IV for pediatric patients to prevent bradycardia & asystole• Give Lidocaine 1.5mg/kg IV, if raised ICP is anticipated (head injury, meningitis, SOL in brain)
Confirming the tube placement• Five point auscultation• Look for equal chest rise• End tidal CO2 detectors• Esophageal detector devicesNote: Visualizing the tube going through the cords is the best method of confirmation
Misplaced ETT• Right main stem intubation: - Breath Sounds more on right side - Deflate cuff, pull back about 1 inch, reinflate, ventilate and reconfirm• Esophageal intubation: - Sounds primarily over epigastium - Deflate cuff, remove tube - Hyperventilate patient for another 1-2 minutes, - Reintubate
Other techniques of intubation• Nasotracheal intubation- Blind procedure • Trismus, TM joint arthritis, • Risk of bleeding is high • Difficult in apneic patients • Patient may have sinusitis later
Digital intubation• Indicated in children and patients with micrognathia• Handy technique when laryngoscope is not available
Retrograde intubation • Rarely required in Mallampatti class 3 & 4 patients
Indications:Failed intubation due to anatomy (short, obese neck), disease states (epiglottitis, laryngeal edema), trauma (C-Spine #, mandibular #)
Needle cricothyroidotomy• Insertion of a large bore IV catheter through the cricothyroid membrane.• Easy to perform but greatly inferior in providing adequate ventilation.• Patients can be ventilated only for 20-30 mins.• I:E ratio should be 1:10 to 1:15
Surgical cricothyroidotomy• Preferred over needle cricothyroidotomy.• Contraindicated in children <12 years- late airway complications• Diameter of the tube inserted should not be >7mm.• If airway is needed for >3 days, cricothyroidotomy should be changed to tracheostomy
Surgical cricothyroidotomy• Make a small vertical, or horizontal incision over the skin and subcutaneous tissue.• Perforate the cricothyroid membrane with the blade,• Place the back of the scalpel handle into the incision to widen the opening• Insert the ETT, inflate cuff and secure the tube with adhesive tape
Surgical cricothyroidotomy• The only vascular structure that may get injured during the course of a properly performed cricothyroidotomy is the thyroid ima artery• Rx- Surgical ligation