1. Laryngeal mask airway Dr. S. Parthasarathy
MD., DA., DNB, MD (Acu), Dip. Diab. DCA, Dip. Software statistics-
PhD ( physiology), ( IDRA )

2. Supraglottic device – the first
standard fixtures in airway management, filling a niche between the face mask and the tracheal tube in terms of both anatomical position and degree of invasiveness.
These devices sit outside the trachea but provide a hands-free means of achieving a gas-tight airway.

3. History Archie Brain – Supraglottic approach was less traumatic
Gold man mask in his dental anesthesia clinic
Nasal mask was possibly similar to laryngeal inlet
Connected the tube with the rim
Prototype LMA in 1981

4. From the internet for closed academic purpose only

5. 1983 – first published article in BJA
1985 Katz MD popularized the use in US
Slowly commercial devices
Replaced ETT in the use as such in number of cases
Various modifications !!

6. LMA – classic
It consists of an oval soft silicone mask that sits over the larynx with an integrated stem that extends through the oral cavity to allow attachment to the anaesthetic circuit or other appropriate equipment.
Mask when inflated, fits around the laryngeal inlet and supports it in a position away from the posterior pharyngeal wall

7. Mask like a bowl continues as a stem to end in a 15 mm male connector for a breathing circuit
Mask and stem – 30 degrees
Inflatable mask – tube, pilot balloon , valve
Grilles across the mask for preventing down folding of epiglottis.
Silicone rubber – 40 times autoclavable

8. Taken from internet for closed academic purpose only

9. INSERTION TECHNIQUE Something like swallowing
Deflate smooth, Fbs, pilot balloon
Sniffing position
Jaw assistant
pen hold – index at junction
Black line centre of upper lip
push for hard palate
Release pull assistant
cuff tip flat against palate --See folding of tip.

10. Continue pushing with left hand
Resistance
Anterior laryngeal displacement
Inflate to desired ml to see LMA slightly coming out

11. When properly placed, the mask rests on the hypopharyngeal floor
When properly placed, the mask rests on the hypopharyngeal floor. The sides face the pyriform fossae, and the upper border of the cuff is behind the tongue base
Other techniques
Partially inflated
Retromolar and turn
Lateral in high arched palate
Release cricoid pressure if not

13. Seals !!
pharyngeal seal.
During controlled ventilation efficacy is dependent on factors such as whether the device orifice sits over the larynx and the quality of the device seal with the laryngopharynx
esophageal seal
Reducing aspiration risk requires a good-quality seal with the hypopharynx and/or oesophagus

16. If the epiglottis has downfolded, moving the LMA up and down without deflating the cuff may help to reposition the epiglottis. Another maneuver is to withdraw for 5 cm and reinsert
My fixing – gauze piece and a plaster as bite block
Intubate through LMA if needed
Maintain anesthesia

17. Extubate LMA – my option
Supraglottic device – hence patient acceptance is better
Small dose fentanyl , cut off agents , awake
Reverse and totally awake
Deflate – remove the LMA – ask the patient to swallow
No suction in LMA removal

18. Although careful placement, cuff inflation, and adaptation time improve the seal, leakage often occurs at 20 cm H2O airway pressure with the classic LMA.
Obesity, a head-down tilt, abdominal insufflation, airway obstruction, or any other conditions necessitating ventilation with high airway pressures increase the risk of hypoventilation, gastric insufflation, and regurgitation

19. Taken from internet for closed academic purpose only

20. Advantage LMA !! Professional singers Remote locations Resuscitation
Endoscopies
ESWL

21. Complications
injuries have been reported with LMA use, including injuries to the epiglottis, posterior pharyngeal wall, uvula, soft palate, tongue, and tonsils
Sore throat
Ventilate ? Change of head position ?
rare complications include 12th cranial nerve paralysis, unilateral hypoglossal nerve paralysis and transient bilateral vocal cord paralysis

22. If gastric contents are seen in the laryngeal mask, the patient should be placed in the 30° head-down position, the LMA left in situ, anesthesia deepened,
and the breathing system disconnected temporarily to allow drainage and suctioning of the airway tube.
Intubate if aspirated

23. LMA-Unique
The single-use LMA-Unique (disposable laryngeal mask airway, DLMA) is made of polyvinyl chloride and costs less than a reusable LMA
tube is stiffer and the cuff is less compliant.
It may be helpful to warm the tube before insertion

24. The reinforced (or flexible) LMA
The reinforced (or flexible) LMA (sizes 2-5) is an alternative version of the LMA in which the tube is thinner, narrower and longer and is reinforced with a spiral of steel wire to add flexibility and reduce the risk of kinking;
Difficult to insert. can rotate later
Tongue bite safety , no in MRI
But nasal surgeries , tonsils !!

25. Insertion of an LMA is frequently difficult in patients in whom tracheal intubation is difficult.

26. Aspiration is the danger?
Proseal LMA ( pLMA)
Aspiration is the danger?
Can we decrease leak ?

27. Drainage tube with a ring
No grille
Cuff s- 2
Anterior and posterior
Reinforced tube
- Hence narrower
Bite block

28. pLMA Greater depth Technically more demanding insertion
The device may be introduced digitally or with a special introducer.
Bougie to drainage tube and esophagus
Bougie to larynx – straight to main tube
Laryngoscope or a tongue depressor

30. Position ??
(1) The PLMA may not be inserted sufficiently far, with the consequence that the tip of the drainage tube lies in the pharynx. Positive-pressure ventilation is ineffective because delivered gas passes out the drainage tube.
(2) The tip of the PLMA may lie within the glottis, thereby obstructing ventilation and impairing function of the drainage tube.
(3) The tip may be folded over and obstruct ventilation and the drainage tube.

31. Gel to proximal portion of drainage tube
The drainage tube gel does not move with positive-pressure ventilation or brief firm pressure applied to the sternum.
The drainage tube gel does not move when airway pressure is raised to 20 cm H2O.
The drainage tube gel moves slightly when brief “bobbing” pressure is applied to the suprasternal notch (the mechanism is pressure on the esophagus).( SS notch test )
Catheter inside drain tube

32. Clinical pearls Can we nebulize ?? Pregnancy more than 14 weeks ??
Prone position ??
Classic 20 cm Vs 30 cm peak pressure for pLMA
Cuff pressure is 60 cm for both
Limit of surgical duration – 2 hours but with proseal 12 hours reported

33. Supreme LMA . Similar to the pLMA,
sLMA has an improved cuff design that produces higher airway leak pressures,
drainage tube that allows for gastric access,
integrated bite block
Fixation tab to insert and to find size

34. Other SGD in next classes
Summary
LMA – history
Types
Classical insertion tecniques
Indications and contraindications
Merits and demerits
Supreme
pLMA
Thank you all
Other SGD in next classes